Sunday, 14 October 2018

Oil Filter Removal Tool - episode 220

Trying to do an oil change on my vehicle today and I couldn't get the oil filter off.
 Unfortunately I just couldn't break the seal holding it in place and my options were a bit limited. 

That's what I love about having a CNC machine. In this situation I would have been left with no choice but to resort to butchery or worse still buy the tool for removing the filter.  

It occured to me that I could try and make one. I know they aren't that expensive but why not make one. After all I'm changing the oil myself so I might as well save a few extra dollars if I can. Drawing it is not particularly dificult and as it turned out it only took 5 minutes to do. For the prototype I'm using some 12mm MDF which I have laying about the workshop. 
Because the shape has 15 flats on it I had dificulty measuring it properly so decided to cut the hole out first and could then test the new filter in the hole before proceeding with the final cutout. Just as well I did because I needed to enlargen the hole by 0.5mm to get a good fit. This is simply achieved by creating 2 profiles using the same tool but give the tool a different number between profiles. this will force the machine to stop at which time you can test the filter in the hole and if it fits then hit cycle start and the machine will continue with the cut. If it doesn't fit then hit the cycle stop, load a new file and recut.


Click to view


The Result
Well there is no doubt about it, the tool worked, even if it had to be shortened a bit. I have redrawn it and created a second tool for the smaller oil filter on Mrs CNCnutz car, just in case she needs it to change the filter.
After using it it looks like MDF is more than strong enough for the job unless the hulk does the next oil change and tightens the filter to excess. I can always cut one from plastic like HDPE if I need to.

Files
The files are available for download for anyone who wants them.

Toyota surf 1998             http://bit.ly/2On6Rpb

Toyota Corolla  1996       http://bit.ly/2PxvI6h
 




Cheers
Peter






















Tuesday, 11 September 2018

Dust Collector Thein Separator - episode 219

Continuing on from the hose install I am now moving to the Dust collector itself. I own a 1hp basic dust collector with the standard ba at the bottom and a filter bag at the top. While it works well it is a bit of a hassle to empty the bottom bag as well as clean out the filter bag. One option is to install a cyclone inline with the DC hose and have it filter out most of the dust before it reaches the dust collector. Unfortunately I do not have the room for such an installation in my workshop. I want everything to be compact and reamin within the footprint of the existing Dust Collector. To put it another way i want it all.
With a Cyclone out of the question I decided to install a Thein Separator. It is basically a compact version of a cyclone which can collect most of the dust and woodchips before they get to the DC. No cyclone is 100% efficient and due to the compromises employed in the Thein separator design it is less effective than a properly designed cyclone. Some people may argue different but given the simple design and compact nature of the Thein, if it really was better than a cyclone, it would have replaced them years ago. 
This is my take on a Thein Separator designed to fit under the Dust Collector.


 Click to watch


Materials used
Made from a cut down 65 litre (17 US gal) oil drum. It was cut down to just fit under the DC. The plastic parts are a piece of 100mm water pipe and a 100mm 90 degree elbow. Mine is a bit beaten up as it was previously used on another project. There are 3 lengths of threaded rod to hold the baffle in place. the rods are longer than needed to allow the baffle to be positioned further down if needed. By moving the baffle up and down I should be able to fine tune the separator for the best performance. the top is cut from 22mm (7/8) plywood and the baffle from 4.75 (3/16) MDF. Having learnt my lesson with the vacuum table build I avoided MDF as the top of the unit due to how porous MDF is.

The down side
You don't get something for nothing and this is no exception. The introduction of the separator between the DC and the hose will introduce an inevitable loss of vacuum. This is true of any cyclone system. I can see a reduction in vacuum at the dust shoe as the bristles no longer pull in when the vacuum comes on. MY DC is a bit on the weak side and it has difficulty lifting larger chips. Unless the brush is sitting so that it seals to the table or stock it will usually not lift the chips very well. These chips are usually picked up as the cut proceeds and the dust shoe gets lower. The obvious solution is the get a bigger DC with more power but is it really? My thoughts are that so long as the dust is collected then I'm pretty happy. Chips aren't a problem and will be picked up a bit later on in the machining so no problem. It's the dust that really concerns me. It isn't good for the lungs and it floats around the room until it settles over everything from one end of the workshop to the other. The DC in my setup takes more power to run than all the rest put together and getting a DC twice the power and running it for hours on end to do what my smaller more economical unit will do eventually seems a waste to me. Just my thought and the fact that I don't have the room for one that size settles it for me.

How does it work?
I haven't had a chance to really test it yet but a quick test had it picking up dust and chips as expected. I think it will prove to be a worth while addition to my DC. If at the end of the day it isn't sucessful, I can simply connect the hose direct to the DC and bypass it. Only time will tell how well it will work for me.

More information
The Thein separator was designed by Phil Thein and here is the original website showing his design.    
http://www.jpthien.com/cy.htm


A great video of a see through Thein separator in action. 
 https://www.youtube.com/watch?v=3QCAOwSqrko
 


As usual thanks for taking the time to read and watch and I'll catch you next time.

Cheers
Peter

Tuesday, 28 August 2018

Dust Collector HoseSupport 2 - episode 218

I admit it
The hose support I made in the last episode didn't look and work the way I immagined when I designed it. The DC Hose old and not as flexible as it was when I purchased it all those years ago. At the same time I also bought a flexible 4" flexible VentilationDuct and it is still as good as the day I bought it. It has Aluminium on the outside and plastic film on the inside. The plastic walls are very thin and that makes it very flexible indeed. This is not made for use as a dust collector hose and while I'm sure it will not be damaged by dust and woodchips I can't say the same about small peices of wood picked up by the DustShoe. The only thing I have gong for me in that respect is the Dust Ciollector I have is only 1hp and it doesn't pick up too many larger pieces of material. Only time will tell if it will survive but it could be destroyed on it's first time out. I do not recommend you follow my lead in this  until it has proven itself one way or another.
I can kiss my 3 year warranty goodbye on it to start with and if it is still working in 3 years I will be astounded.



Click to view

My Thoughts
I do like the look of the new setup and the cost of the Flexible duct is only $14 so it's worth a try. If it does bite the dust, (so to speak), then no big loss and I will pull the original hose forward down to the DustShoe as I should have enough length to reach. If not i will cross that bridge when I get too it.
I also need to find a way of storing the DustShoe when I don't want it connected to the machine as I sometimes video without it to give better visibility.
Static is a possibility with this hose as with any DC hose. The plastic isside and the metal outside might make an interesting combination. Fortunately if it does prove to be an issue grounding it will be very easy but i will wait and see what happens.






This is the flexible duct I have used if anyone is interested














Not much else I can say about this. I hope you enjoyed the episode and I will see you on the next one.

Cheers
Peter









Saturday, 25 August 2018

Dust Collection hose support - episode 217


Pimp my Hose
Chip's back and he's not happy with the state of my dust collection hose. 
Can't say I blame him really and I had a good suggestion from a subscriber, (sorry I can't find his email to give proper credit)
Us a piece of pipe to support the hose and ensure it can't get a sharp bend in it. The sience of air flow in pipes is well beyond me but the basic thing to know is to have nice gentle bends and smooth inside surfaces. The hose I have is far from smooth inside but at least I can reduce the sharp corners. 

Click to watch Video


The Result
Not reallly sure how I feel about the result so far.
It keeps the hose up and it looks tidier on camera but I could have done that by shortening the rope. It does eliminate the sharp bends in the hose so that is good and should improve air flow if only a little.
I am very interested in hearing what ideas you guys have and seeing if I can improve on the design or even abandon it and start something new.

VacuumTable
This is the first on camera use of the vacuum table and is the sort of project it was made for. Holding thin material flat so it can be accurately cut. The new AutoZero Macro made cutting this project possible without cutting up the Tabletop.

UCCNC Macro upgrade
I also announced the new UCCNC AutoZero tool setting Macro from John Revill.
For those who are interersted it can be down loaded here
http://bit.ly/2HVpEQY

This brings the UCCNC version in line with the changes made to the Mach3 script earlier in the year. 
The addition of a Pre Touch test before the probing can begin will ensure that you have a working circuit so that the cutter will crash into the touch plate. This is particualy useful for those people who have to remember to clip a lead onto the cutter.

The macro has been provided in both Metric and Imperial flavours.
The new Macros have a built in touch test which must be performed before the AutoZero 
routing will start. After entering the material thickness offset you have 30 seconds to touch the 
touchplate to the cutter. When connection is detected the PC will beep and you have 2 seconds
to replace the plate on the table or stock surface.
2 seconds is longer than you think!
If a touch is not detected a time out will occur.
There is 1 parameter in the script that you must change, The touch plate thickness
If you have a touch plate with a switch in it the set "bool SwitchedTouchoff " to true
Everything else should be ok.

The Pre Touch test and beep can be disabled if desired but it is not recomended.



Thanks for watching and I'll see you on the next video.
Cheers
Peter


Wednesday, 15 August 2018

Autozero issue - episode 216


This episode is inspired by Ted who was kind enough to share his problem and the solution.
I like a mystery so long as I find out the eventual solution. Probably why I spend most of my time listening to mystery Audiobooks. (no this is not an advertisement for audiobooks)
Teds issue is that despite using the Autozero script that I demonstrated in recient episodes he is having issues with the cutter cutting into the spoilboad even though it shouldn't. He explained how he is using the machine and everything was good so the issue had to be the machine but what?

When it comes to checking things I always check the easiest first. 


 Click to watch

          1. Slop in the spindle / router bearings.
Don't take this for granted even if it is new. It takes a second to check and i have seen the issue on both old and new routers. I have seen people spend hours checking their machine trying to find lost steps when 1 second checking the routers bearings would have told the story.

          2. Slop in the X Z carriage bearings. 
This would equally apply to the Y carriages as well but that is even less likely and the test will highlight it as well. Again it is the work of a second to try and flex the Z axis and all will be revealed. You are not looking for flex in the X rail but abnormal movement in the axis. Some machines have more flex than others but you are looking for flex that doesn't belong there. In this case loose bearings. Vbearings such as I use are very susceptible to this as a small amount of wear on a V'ed rail will provide a lot of movement on the axis. Again it is is so quick and easy to check this why wouldn't you.

          3. Unlevel Tabletop
 All wood absorbs moisture and will swell when it does. MDF is a little worse than other woods but so long as it expands in a constant rate over the entire table you don't have a problem. It's when the MDF expands at different rates over the surface that the tabletop can become uneven. This usually takes many months but because the tabletop isn't constantly being scared and resurfaced the effect will accumulate over time. We all know what happens to MDF if you get it wet. It doesn't return to its original size when it drys out. Maybe it should be marketed as the grow your own tabletop. Just water occasionally and when it grows to the height you want just resurface. I of course jest!
The solution is to simple resurface to the lowest point on the table. It will flatten the table and your soilboard will remain the same thickness.

          4. Lost steps
The curse of all home CNC enthusiasts everywhere. Fortunately it is easy to test for and well worth checking if all else fails.

          5. Machine accuracy
This covers the touch off plate thickness and the Z axis calibration. If either of these is out the effect will be the same. Where possible use a dial indicator to calibrate the Z axis as it will give the most accuracy. The small movement of the Z axis will makes it very hard to calibrate unlike the X & Y. 
Likewise the touch off plate thickness measurement needs to be correct. You would be surprised how a shallow cut in the tabletop looks like the grand canyon when the light gets on it just right.I can't help wonder how accurate the cheap calipers are but they always seem to be pretty good.

The solution
Well as you saw the solution was a combination of the touch off plate accuracy and Z axis calibration. These were always the most likely to be at fault but you must never take things for granted. Check everything but do it in a methodical manner or you will simply make things worse. If you find something wrong then fix it and retest. If you still have a problem continue searching but don't hop about like a flea in a fit. Remember that the aim of the exercise is to fix the problem you have, not create new and even more diabolical ones.
Change only one thing at a time.

Thanks to Ted for sharing his problem and more inportantly the solution.

Until next time
Cheers
Peter










Wednesday, 1 August 2018

Mach3 or UNCNC?- episode 215

There are a couple of questions I get asek on aregular basis. 3 times this week already.
Should I change from Mach3 to UCCNC and what do I recommend for a first time builder. Mach3 or UCCNC
Let me start by saying that there are other control softwares out there, so are good and others not so good but the only ones i can really comment on are the ones that I have tried which I why this video is limited to the 2 options.

This is my thoughts on the 2 softwares and why I changed from one the the other.
I leave it to you to decide what is right thing for you.

Click to watch


Mach3 
As mentioned in the video a recent update to Windows 10 has broken Mach3 preventing it from opening. For anyone suffering this problem you can download the latest version of Mach3 which has the fix applied. The new version is Mach3 R3.043
http://www.machsupport.com/software/downloads-updates/

If you wish to read a bit more about it then have a look  here
https://en.industryarena.com/forum/mach3-windows-10-64bit-1803-provisional-patch--360714.html

Windows Updates
The recent issue with Mach3 is a timely reminder that your machines PC should have updates turned off. Windows has a nasty habit of updating when and where it feels like it and if you are in the middle of a cut then too bad.

UCCNC
I you want to have a play with UCCNC to see what it looks like you can download the software and when it open it will ask you to select a motion controller. It will then run as if it has the chosen motion controller installed and you can get a feel for how it runs and configures. Until you but a licence for your motion controller it will not run your machine. 
UCCNC can be downloaded here.
https://cncdrive.com/UCCNC.html

2017 Screenset

If you are interested in the Screenset mentioned in the video you can find it here.
http://www.thecncwoodworker.com/uccnc.html

Gerry has a knack of making Screensets that are clean, easy to use and has added some nice probing routines to his screenset. Should you find you want to change a particular key or script to something that suits your personal requirements then there is no issue and you can easily make your required changes. 

http://www.thecncwoodworker.com/uccnc.html


United States supplier of UCCNC and motion controllers

https://cnc4pc.com/catalogsearch/result/?q=uccnc
 
This is where I purchased my UC motion controller from and they were very helpful so if you are not sure about anything just ask. They were good enough to see that I had missed out a critical piece in my order and alerted me to it. We got is sorted there and then, otherwise I would have received it and had to order the additional parts after realizing my mistake.

When you select your motion controller of choice you will get the opportunity to bundle it with a UCCNC licence which was cheaper than purchasing both items individually.

There are of course other suppliers around the world but I caution you to purchase from a reputable dealer. 

Be careful if buying a UC100 as there have been instances of fake UC100's being sold on Ebay which do not work. You have been warned!!!


Please also be aware that the UC300ETH requires to be attached to a motherboard to work. This can be in the form of a 5LPT board as I have with mine or a 3rd party board which will give additional features like built in relays etc. When purchasing a UC300 ask the supplier to explain the additional board options so you can choose the one that suits you the best. Don't forget to buy any ribbon cables to D25 you might need to plug into your Stepper motor drives.

The UC400 is a nicely presented ethernet motion controller which gives 2 parallel ports. Just remember to purchase the ribbon cables to convert from DIP to a D25 when you purchase this. 

Parallel ports
Yes, I did say that they are almost impossible to come by but before anyone says they can get a PC or even a laptop with a parallel port 2nd hand, I am talking about new PC's not old ones. There are still PC's with parallel ports on the 2nd hand market but they won't be there forever and sooner or later you will need to move with the times.
 Parallel port monitioring and pulse generation is a time consuming task for the PC and in addition it has to put up with the constant dribble that Windows thinks is important.
Windows is a truly horrible platform to build a realtime application on like a CNC machine and it is a marvel to me that Mach3 and the others do it so well.  I take my hat off to them.
Changing to a motion controller removes the need to generate pulses and monitor the pins for signals and allows it to get on with the rest of the job. This reduces the load on the processor and things run better.

Well that is enough from me for this video.
Please feel free to comment and share and  I will see you next time.

Cheers
Peter

Friday, 29 June 2018

Making a new grate - episode 214


I needed a replacement grate for my drain and I needed it quick. The property is getting an inspection tomorrow and I wanted to make sure the drain had a propper grate in place. I also wanted to make sure that the cats or other animals ended up falling in head first.
After looking around town I found that these are no longer made and I would need to make my own. With time ticking away I made this replacement with some PVC material I had on hand. It came out really well and should last for many years. I may even get carried away and make one from Aluminum.
While ideally I would have liked to 3d model the rate and add sloping sides time did not permit but I did manage to model it later on that evening and have provided the model here for anyone who wished to make their own.



Click to watch


3D model
Saved as both Aspire crv3d and STL formats

http://bit.ly/2Kt2W7v


2D model
Saved as a DXF file

http://bit.ly/2MzQBMq

Saturday, 9 June 2018

How to calibrate your CNC machine - episode 213

This video is a natural sucessor to the previous one on squaring your machine.
If you do not calibrate your machine then noting you make will be the right size. The larger you make an item the larger the sizing error will be. Depending on what you make with your CNC the lack of calibration may or may not be an issue. If all you do is cut 3D models then any sizing error will go unnoticed but if you are cutting inlays then the penalty for an inaccurate machine is parts that do not fit as they should. Fortunately there is a simple way to fix this problem. 
Mach3 and UCCNC have built in calibration that allows you to check real world movement against the calculated movement and then they calculate new steps per unit values automatically for you.


Click to watch

 Calculations
The calculations can be a bit daunting and to make things easy for you I have created a spreadsheet you can download that will calculate everything for you.

 http://bit.ly/2JFs4Yk

Only the figures in red can be changed.
While the Leadscrew part of the spreadsheet is straight forward please read the Notes section at the end of the Rack & Pinion calculation to select the correct value to enter into your machine.
If you find an error please let me know and iI will correct it ASAP.

Assumptions
Unless you are using precision components it is likely that you will see errors in the real world measurements and just because you are using the same components in on various parts of the machine doesn't mean that they will give the same result. This is especially true of Rack and Pinion. My X & Y are identical but the calibrated values are different. Only slightly but different none the less.

Sanity
While it is nice to get everything perfect there are limits to how perfect you can get things using rulers and pointed sticks. I do not recomend using a dial to set the X & Y axis unless your machine is very small indeed. The larger the measured distance the more accurate your final result will be on a large axis. The error reduces as the item you cut becomes smaller.Measuring over a large distance take into account any non linear error in your leadscrew or rack.
Remember that this is a hobby machine and do not take this to extremes.

Making the pointed stick
If you didn't see the previous video I have put a link below to take you to making the pointed stick I used for calibration Quick and easy to do.

https://youtu.be/lU0iZKajpoo?t=3m11s

Square your machine.
If you haven't already done so then I recomend you watch my last video on squaring the X & Y axis on your machine. Unless you do both the calibration and squaring your machine will not cut properly. You can conbine both processes and have the whole lot done in under an hour.

I hope you have found this useful and I will catch you next time.
Feel free to leave a comment either here or in the video comment section.
I always enjoy hearing from viewers.

Cheers
Peter

Tuesday, 22 May 2018

How to square your X and Y Axis - episode 212

Like tramming the Z axis on your machine to be square to the tabletop, Squaring the X and Y axis is another job you need to complete for your machine to cut accurately. The biggest problem with this is it isn't as simple as grabbing a square and checking it. Machinists squares are far too small for this task and builders squares are not really accurate enough. Even if it was then on a large machine like mine even a builders square is too small and there is nowhere I can put it to reference square from anyway. This is true of most CNC machines but none the less it has to be done and done accurately.
If your X&Y are not square to one another then nothing you cut will be square. 
The good news is that it takes very little in the way of technical knowledge and tools to set your axis up square and when you are finished it will be super accurate.
For this we will use Pythagoras's theorem but don't worry if you aren't good with maths.


Click to watch video




 Pythagoras's theorem
 The square of the hypotenuse is equal to the sum of the squares of the other two sides.

  
 
 
              {\displaystyle a^{2}+b^{2}=c^{2}.}




  
The 3,4,5 Triangle
 While it is handy to know the actual theory there is an easier way to use it and that is by simply using the 3,4,5 triangle


This method is used all around the world by builders to set things up squarely when it isn't possible to use a builders square. If you wanted to set up boxing for a large pad for a building you would use the 3,4,5 triangle to lay everything out and this is also the best method for us to use on our machines. The bigger the triangle we use the better. Each side of the triangle can be multiplied by fixed amount and the result will always be correct. In the Video I multiply each side by 200mm giving me  600 x 800 x 1000mm but I could have just as easily used 8 inches which would have given me 24 x 32x 40"
If my table had been a bit larger I could have gone 3 x 4 x 5 foot. So long as the same multiplier is used for each side then it will hold true.

Now I have square what do I do with it?
This process is something you only want to do once so when you finally get it set right you need to have a simple way to resetting it each time you use your machine. There are 2 methods for doing this. You can either set your hard limits to be a reference or set up auto squaring.



Hard limit squaring
This is my preferred method to square my axis. Simply engage the Estop and manually pull the gantry toward the front of the machine until it rests on the Hard limits. Then release the Estop and it is done. Of course if you are using leadscrews then the gantry needs to be driven into the hard limits as you cannot pull against the screws like you can on a rack and pinion machine.


Squaring with homing switches
No matter how good people think having homing switches are, and I have nothing against them, you still need to go through this process to establish what is square in the first place. From there you can position the homing switches for the auto square. Don't forget to test the auto square feature after setting them up to make sure that all is working as it should.

Calibration
You need to ensure that both your X and Y axis are moving exactly the correct distance or your results will be meaningless. If you find that they aren't then use the calibration tools built into Mach3 or UCCNC to correct the error. If you are using control software that doesn't have a calibration feature then manually adjust your steps per unit until the axis move the correct distance.

Measuring
I recommend you use a steel ruler rather than a tape measure as a ruler is easier to manage. In the video I used a 1000mm rule so that is why I chose to make the longest side of the triangle 1000mm. 

If you need to use 2 rulers as I did in the video then make sure that the units of measurement are the same on each by comparing them against one another. I have seen instances where some rulers are not the same. This isn't a problem as such so long as the divisions on the ruler are even and you use the same ruler for all measurements but it is a big problem if you change rulers part way through. 

The pointy bit
I don't recommend you use an engraving bit for this as the point on them are off centre. The pointed stick I made only took a minute to make and was ideal. I left is about 0.5mm or 0.002 of the table top while jogging around. Just high enough to get the tape under.

Marking
While I was doing this video I found that already having the cross drawn on the tape and sliding it under the point was the best way of doing it. It is unbelievably easy to do and accurate.
In the past when doing this I either jogged the point over the cross at the starting point and  tried to draw the cross under the point at the end. Both methods very frustrating, time consuming and inaccurate.

Final thoughts
Is is really handy once you have your machine square to run a cutter down the sides of your spoilboard to give yourself reference edges for setting stock on the table and other things.

I hope you find this information useful and can get your machine set up nice and square.
Don't forget to tram your Z axis as well or you will only have done half the job. For he machine to work right you need to have everything set right. If you want to know about tramming your Z axis please follow the link below.

https://www.cncnutz.com/2017/01/how-to-set-your-router-perpendicular-to.html

Until next time
Cheers
Peter

Monday, 30 April 2018

DIY Vacuum Table Part 2 - episode 211

Following on from the last episode I have made changes to the Vacuum table to get the project back on track. Many thanks to those who provided feedback and suggestions on possible fixes to the problems I faced. In the end I opted for the simplest solution of painting the MDF base and the edges. This sealed the table very nicely and because most of the vacuum was being lost throught the bottom of the table I added a vinyl sheet puchased from a local craft shop for a couple of dollars. It is very effective and enures the perfect seal on the bottom. Once this was done the vacuum was restored along with its holding power. The solution I used was only one of several suggested by viewers all of which would have worked
Suggestions
Use a non porus material for the base like Plastic sign board or HDPE
Use Malamine coated MDF and seal the edges with edge banding.
Seal the MDF with paint, shellac or similar product. 
Leave the vacuum running while painting to pull the paint deeper into the MDF to get a better seal.
Cover the MDF with a vinyl or similar coating.

Here's the final result.

Click to watch


Getting a better seal
Even with the table sealed and maintaining the vacuum the issue of sealing the material to the tabletop remains. With the table flat there are still small paths for the vacuum to escape due to material imperfections. What is needed is come form of gasket to get the good seal and many solutions use Orings. these won't work if you want to cut through the material as I do and making special vacuum bases per project isn't practical.
I remember Micheal, who visited me about 18 months ago, telling me he used some form of material between his vacuum table top and the stock to get a better seal. I can't remember what it was but I had an idea to put a piece of newspaper on the table surface and see how that went. To my surprise and great pleasure it makes a huge difference to the holding power of the vacuum. It will reduse the air flow through the unused holes while alloing the vacuum to build up under the stock. I will also provides a little clearance between the tabletop and the bottom of the stock so when cutting through the cutter won't touch the table surface all going well.

Small Holes
The use of the small holes in each pod looks to be just ideal. The vacuum pulls very quickly but even with most of the pods uncovered or covered with paper the vacuum seems to have good holding power. Had I put 1/4" holes in in each pod the uncovering of just 1 or 2 of them would have meant loss of vacuum on the entire table. It also eliminates the need for sectioning off areas of the tabletop though if I had made it larger it mag have been necessary.

Vaccum source
This is the hardest problem to solve and something you need to be aware of.
Vacuum cleaners are not made to but used with vacuum tables. While they obviously work and are used by many people the restricton of the hose robs the cleaner of the necessary cooling air it needs to keep the motor cool. If you don't cool the motor it WILL burn out. The vacuum I used in part 2 of this video is made by Festool but has been superceeded. It has seperate cooling for the motor so is a good option for this project. 


















 The motor cooling outlet can bee seen as the grill on the front of the cleaner and the exhaust for the vacuum is visible on the left hand side of the cleaner. when you block the hose the exhause on the left stops but the one at the front keeps blowing. the only down side of these is the cost but it is a professional unit made to collect fine sanding dust etc. At over $1000 for one of these I think I will borrow my brothers on the occassions I need it.
Other options are real vacuum pumps though I dont know what size pump is really needed for this application. Ebay has some cheep ones at less than $100 USD but whether it will work with a midsize table top I don't know.
The other suggestion was to convert an air compressor to pull a vacuum. After all while it blows at one end it has to suck at the other. I'm told it can be done quite simply and not loose the compressor function. 
I actually have a 2 stage vacuum pump that I used to use as a compressor but its piston seals are damaged and it will not pull a vacuum any more. If I can find a suitable material I may be able to repair it but in the meantime the current setup will work just fine.

Please be aware of ordinary vacuum cleaner limitations.

Well that is all for this project. I am looking forward to using it on an upcoming video so until next time

Cheers
Peter

Monday, 16 April 2018

DIY Vacuum Table - episode 210

I finally have gotten around to making a vacuum table for my machine. I was planning to make one the fill size of my tabletop but decided it was a bit ambitious for a first attempt. How right I was.
The idea for this build was built on one simple idea. Large holes for the pods fed by tiny holes such that even if many of the holes are uncovered the vacuum cleaner that I plan to use fore this projecj will still be able to keep the vacuum up to the rest of the pods. This is the mistake made in many designs that I have seen. They use large holes which as soon as they are uncovered, the vacuum source can't keep up with the air pooring in through the holes and the rest of the pods loose their vacuum as well.
By keeping the holes small the effect of uncovering these holes is minimal and the rest of the pods should keep their vacuum. The price to pay for this it the increased time to pull a vacuum on the individual pods but this is very minimal.

So what went wrong?

Click to watch

MDF is a porus material 
You don't need me to tell you this. If you have ever tried to paint it you will know it acts like a sponge and soakes up the paint like a thirsty man in a desert. I therfore thought it might loose a bit of air through the sides and I might need to seal the edges. I did keep plenty of material between the channels and the edges to reduce this but I wasn't prepared for the results. I had thought the compressed surfaces would be immuned to the air being pulled through them but how wrong I was. Inital testing early on in the buikld showed the MDF held the vacuum of but as time went on the MDF became more porus to the point where it doesn't really load the vacuum when the entire surface is covered. 

Where too from here?
 I have already come up with a simple way of fixing it and will be giving that a try next.
It has also given me a crazy idea on how to make the workds somplest vacuum table which I will give a go as well.

Until next time.
Cheers
Peter
 





 

Wednesday, 4 April 2018

Joining Stuborn vectors in VCarve and Aspire - episode 209

This video is inspired by a subscriber who was having trouble closing the vectors on a project he was making. This video will show the issue and solution to the problem. Hopefully you will find it useful if you have a vector that stubbornly refuses to behave.

The problem is a lot more common that you might think and if not closed correctly can cause more problems than it solves. Simply increasing the tolerance of the join feature can sometimes be the worse thing you can do. Vectric software offers many tools that make drawing easier and there is more than one way to achieve the same thing. the trick is finding what is right for you and what gives the result you are looking for.


 Click to watch


Software used in this Demonstration
For this demo I used Aspire V9 from Vectric. I have been using Vectric software since 2006 and find it to be an easy to use in my day to day projects. I am yet to explore the 3D drawing features of Aspire as I have only just upgraded but the 2D functionality is the same as VCarve Pro.


Experiment
Many episodes are created as answers to viewer questions and I thought I would try this to see if others are interested in small videos like this one. I could be opening myself up to an avalanche of drawing questions so I will need to see what happens.

In the meantime I hope this helps and I'll see you on the next episode.

Cheers
Peter


Thursday, 22 March 2018

How to Modify a Mach3 Screenset - episode 208

This episode is a revisit of a video I made almost 2 years about configuring my Mach3 pendant and modifying the screenset. What I didn't realize at the time was the screenset was messed up when the screenset editor opened the file. While it was subtle a viewer who was having the same problem contacted me and pointed it out. Until I saw it on my video I hadn't noticed it but now it was obvious. I tried at the time but couldn't get it to work and I still don't know why it doesn't work. Changing computers to edit the screenset seems to make thing much worse to the point that it was impossible not to notice and even more impossible to use the screenset. In my defence I don't use the 1024 screenset in my day to day machining and the editor worked well with the screenset I use. I picked on the 1024 set because it comes with Mach3 so everyone has it and in theory one screenset is as good as another. 
A few weeks ago I was helping another subscriber with a problem he was having and decided to add a digitizing LED to the screenset main page which meant I was back battling my old friend the screen editor again. This time I tried the newer version editor Screen4 and found it works well with the 1024 screenset. With the new skill learnt I thought it would be a good opportunity to update my previous video and introduce the pendant to new subscribers as I find it an indispensable addition to my machine. Especially with the modified keys on it. It is also a good opportunity to introduce the updated Mach3 Autozero script which gives added safety to the script.

Click to watch the video


Screen4
The software used to edit the screenset is available from the Mach3website on this page.
http://www.machsupport.com/software/downloads-updates/screensets

Direct download link.
http://www.machsupport.com/wp-content/uploads/2013/04/Screen4.zip


Buttons, images, DRO's, OEM's and much more
The Screen4 software allows you to add more than just an LED to the screnset. You can add the entire range of components needed for your screen. It is well worth taking the time to have a play and see how a screenset is made. Wile I only added with an LED the priciple is the same for all the other components. Selct the component type from the left havd column and click to add it to the page. Drag  to the required location and double click to open the properties. Enter the required changes and that is it.

List of OEM codes used in Mach3
http://www.machsupport.com/Mach3Wiki/index.php?title=OEM_Buttons


The new Screensets
If you would like to use the new screenset you can fint them here
http://bit.ly/2HUpvgp


The New scripts
If you would like to download the new scripts with the touch test functionality you can download it here. They can be found in the Mach3 folder. Select either Metric or imperial depending on your machine and don't forget to change the plate thickness in the script.
http://bit.ly/2HVpEQY



Pendant
If you are looking for a pendant similar to mine this it the current version. It has a 4th axis that mine diesn't have which you can use either for a 4th axis or another function of your choosing simply by changing the screenset  as shown.
The link will give you multiple search results so you will want to fine a pendant that looks the same as the picture below and at the best price for you.

This particular pendant is available from multiple sources such as Amazon, so it will pay to look around. The link below is an affiliate link.
http://ebay.to/2HXaaMl




Where to from here?
This will help those who wish to modify their existing screenset to add additional functionality or even make a new custom screenset for your machine. you are only limited by your imagination. 

I hope you find it useful and until next time keep those chips flying.
Cheers
Peter


Saturday, 10 March 2018

Lets talk about Stepper Motors - Episode 207

Stepper Motor kits abound on Ebay and unfortunately all too often they are not very good kits.
They sound great. Huge holding torques, very very reasonably priced drivers, motors and power supplies. Unfortunately most of these kits use poorly designed stepper drivers, they are feed with low voltage power supplies and the motors are a very poor match for the drivers that have the job of making them turn.
 
In this video I try and show the issues associated with stepper motors, why they are as they are and how to choose a well matched system. The drive system on your machine is the biggest hardware investment you will make and one of the most important. It doesn't matter how good the machine is, if your drives are rubbish so is your machine.

 Click to watch video



The biggest myth of stepper motors is that bigger is better.
While in some respects this is true, there are certain criteria that must be met. The motor, driver and power supply must compliment one another to get the best out of your motors. A small well matched system will invariably out perform a poorly matched motor / driver / power supply combination.
Stepper motors are rated in holding torque which is how much power they have when they are doing nothing. The larger they are the better they will do nothing for you.
Big stepper motors are sold to catch the buyer not run your machine. The bigger the motor the bigger it's internal losses are and the more power you require overcome these losses and drive them properly. Don't get me wrong. There is nothing wrong with a properly driven stepper motor and in many cases large motors are needed to move heavy axis. Generally though the home builder making their DIY machine does not need to exceed 400 ozin or so unless it is a big heavy machine they are building or they need it to move very fast. Medium powered motors are more common in this hobby.
The problem comes when kits sold on the likes of ebay driven by a TB6560 based driver board using a 24 volt power supply and trying to drive 425 ozin motors. The TB6560 boards were never very good to start with and many of the boards have design flaws that have been extensively discussed on the CNC Zone over the years. The voltage is way too low to drive a medium size stepper motor and many of the adverts don't even give you the basic specs of the motors.
It is vitally important to check the spec on every part of any kit being offered and make sure it is a reasonable match for the rest of the system. If it isn't or there are no specs then move on and find something else.

Additional Information

Click the link below to download the Spreadsheet for calculating Drive voltage and current requirements.
http://bit.ly/2I3SLSW

Click the link below to visit the Gecko site and read their Stepper motor guide. 
http://www.geckodrive.com/support.html 

Stepper Motor Basics
https://www.geckodrive.com/support/step-motor-basics.html


My personal opinion
One thing in Geckos stepper motor guide that I disagree with is the sizing of the motors. While I am sure they are correct in their assessment, they are talking about a product you may be producing that will never change. As a hobbyist we are constantly tinkering and upgrading. In the case of purchasing a Gecko G540 I would purchase the largest motor that it could correctly run rather than one that fits my needs today. In the case of the G540 that is the 381 ozin motor I showcased in the video which if memory serves my correctly was actually specially made to compliment the G540 drive when it first came out. No matter how big a motor you put on it you will not get any more power out of it. A larger motor will give you more power at slow speed but as you try and move faster it will rapidly loose power and the 381 ozin motor will out perform it. Not only that but that little motor is capable of running a range of Joe's DIY CNC machines built up to 4 x 8 foot configuration for example. 
They will drive your small machine today and can be moved to a larger one tomorrow.

It is also important to note that Gecko are not the only makers of good drives systems on the market but the G540 is the only one that I have experience with which is why I reference this one.

4 Axis Drive kit.
I wish to point out that by using the links below I will earn a small commission on any purchase you make at no additional cost to you. It is important to note that if you purchase the individual components making up the kits from various suppliers and assembly them yourself you will save yourself money. Your responsibility is to yourself and I will be happy no matter where you purchase your drive solution from so long as they work well for you. I encourage you to look around for the best deal and solution that meets your needs. I have not personally purchased from this supplier but it is a USA based company that is selling this product.

It is important to note that this supplier does have a 3 axis kit but I would recommend asking them to price you this kit and leaving off the extra motor and 12 foot cable if you want 3 axis. Their current 3 axis kit uses a 7.3 amp power supply and if you want to add the 4th motor later you will need to upgrade the power supply to power it. Getting the 12.5 amp supply now will save later on. It never hurts to have a spare motor and cable just in case, if funds allow. Buying a 4 axis motor kit for your 3 motor machine is not crazy. When you want to add a rotary axis or have a faulty motor or cable you will have the parts you need..


With this kit you will need to supply a case or build one to house it in and a minimum of wiring is needed. If you want an Estop button you will need to purchase this separately.
The Gecko G540 has a built in Break out board to which you can add relays and limit switches. Additional wiresare added to the G540 using screw terminals so those who are not comfortable soldering need not worry.

This kit includes:
4 x 381 ozin motors
4 x 12 foot cables to the motors
1 x 6 foot parallel cable  
1 x 48 Volt 12.5 amp power supply
1 x Gecko G540 4 axis drive system



http://ebay.to/2HiENeA
Please let me know if this link stops working or the kit no longer matches the photo above.
Use the contact link on the right.

Mushroom emergency stop switch if you want one.
http://ebay.to/2oYF281