Monday, 3 December 2018

Diagnose your spindle with SpindleTalker - episode 225

Diagnosing a problem with a HuanYang spindle you are installing can be difficult without tools to test with. Sometimes just looking at a problem isn't enough, even if the answer is right under your nose. I hate to think how many times I've stared at something that later turned out to be obvious but at the time might as well have been invisible. If we're honest we could probably all say that. While my knowledge of VFD installation is limited to the VFD I installed on my machine, my experience of fault finding is extensive. To make figuring out where the problem is with your setup it is best to break the setup into smaller pieces and this is where Spindle Talker comes in. Written by Tommy Gilchrist and based on a program by Scruffoid

Please note: SpindleTalker only works with HuanYang VFD's. Please read the information on the website when you download the software.

SpindleTalker is a program that can be used to help diagnose VFD connection problems by eliminating your CNC control software from the equation by talking directly to the RS485 adapter and VFD. Once you have the spindle working under control of SpindleTalker you can move on to connecting it to UCCNC or Mach3. 
Best of all SpindleTalker is very simple to install. Simply drag the 3 files in the zipped folder onto the desktop and away you go. The only requirement is that you have .NET Framework version 4.03 or higher installed on your Windows PC. Fortunately this is only a problem for Windows XP and can be resolved by installing it from Microsoft as demonstrated in the video.

Note: You need an internet connection to install .NET as it will download files as it installs.


Click to watch

If you are using the same VFD settings I used in my RS485 videos then the only thing you need to change on SpindleTalker is the Com port number to match your RS485 port. The rest of the settings should be the same. When you connect to the VFD it reads the settings from the VFD and displays it on the settings page.

SpindleTalker might not solve your spindle install problem but it can be a big help by splitting the install into managable parts. It is a useful tool to diagnose and test. For those who are into learning more you can see the communication over the RS485 interface between the PC and the VFD. For most of us, if the spindle turns on and off and changes speed as it should then we will be happy and will never look at it again.

Lets hope you will never need it.


Sunday, 25 November 2018

How to VCarve a Sign - episode 224

Have you ever been given a strangely shaped piece of wood and been asked to machine it?
This is exactly the sort of job I designed my vacuum table to handle. A piece of material shaped such that my standard hold downs will not clamp it and since I really need to flatten the wood I can't have the clamps on top anyway as they would get damaged. 
Well that is the senario I encountered this week. I need to flatten my wood and position the lettering on it such that it is centered and look correct. Given the shape of the wood this is not obvious at first glance and simply putting my letters in the center would not work. I needed another way of aligning everything.
This is the method I choose.

 Click to view

The Results
It came out as expected with the lettering in the center of the material as planned. Using a photo to get alignment is a good way of getting alignment but you need to keep your wits about you. Set up a reference vector like my oval and scale your photo to this vector. Make sure the vector position does not move with respect to the origin point and select an origin that you can easily locate on the material. It could be sonething as an X that you mark on the material before you take the photo. So long as you have a reference point that you can set your cutter to. After that position your engraving to suit the photo and not the reference vector. the rest is plian sailing.

For this project either VCarve Pro or Aspire from Vectric could have been used. I used Aspire for this one.


so what is the HotBox?
I'm not sure what it is called in other countries but here it is called a Bach or a Crib or at a pinch a holiday home though it lacks the creature comforts you would normally expect while on holiday. The name comes from the basic box shape and the fact that it used a coal range for cooking and heating. Given the fach that it is small and the coal range put out massive amounts of heat you are left with a hot box. As I was growing up I spent most of my holidays here in the middle of nowhere, Surf Casting, rounding up sheep and anything else that was needed.

My work here is done so until next time have a good day.


Sunday, 11 November 2018

Conventional or Climb Cut? - episode 223

When I started my CNC adventure about 10 years ago I didn't understand Climb and conventional cuts. To be honest I still don't to a certain extent. I understand how to tell the difference between the two, I understand that the direction of cut can have good and bad effects on the finish of my cuts. I have read up on the subject and tried to learn as much as I can but at the end of the day it is the observations that I have made while playing with my machine that ultimately determines which machining strategy I choose.
In my testing with cut direction I have always found that conventional cuts give me the best results. Now to be clear my observations are related to cutting wood and wood products like plywood. I m not talking about cutting metal which is a whole other subject that is out of my realm of experience. It is also fair to say that most of what I have read is related to metal work. Even the small amount of aluminium and steel cutting I have done on my CNC was done as conventional cuts and I did not do any testing to see if changing machining strategy would help. I was just happy to see it cut.

Click to watch

The list of climb cut advantages over conventional is long and at first glance it is hard to see why anyone would want to use conventional at all. 
  • Smaller chip load. 
  • Chip thinning reduces heating at the cutter and the load reduces as the cut progresses. 
  • Chip ejection behind the cut prevents recutting of the chips.
  • Longer tool life due to lower stress and less heat.
  • The cutter slices into the the material reducing the likely hood of chipout
  • Better cut quality?
The only thing I have problems with is the last item on the list. When cutting in wood I have not experienced better cut quality. It could be that I run my cutter too quick for climb cuts but why run it slow when conventional cuts do a good job running faster. Maybe the climb cut should be used as a final pass at a slow feedrate. 

I would really like to hear from you and whether you have sucess with climb cutting in wood. It would be good to compare my results with what others have experienced. 

It is always possible that I have been using climb cut wrong all these years and hopefully will learn something new.

Leave a comment below or on the video.
I look forward to reading the comments.


Friday, 26 October 2018

Fix Backlash - episode 222

Following on from the last video I explore further the problem of backlash on our CNC machines and how we can use backlash compensation to fix it. Before we start we first need to now what Backlash is and what causes it. 
Put simply backlash is the effective loss of steps when an axis changes direction. These steps are used to take up the slack in the system before it starts moving in the opposite direction. These steps are not translated into movement in the axis so it doesn't travel the full distance. Backlash is non cumulative so will not increase as the cut progresses.

Click to watch

To measure this we need a dial who's resolution matches or is better than the axis it is measuring. 

Resolution = 1 / Steps per unit

X & Y axis
1mm / 75steps = 0.0133mm    or   1" / 1908steps = 0.0005"

Z axis
1mm / 315steps = 0.0032mm  or  1" / 8000 steps = 0.000125"

It is really important to have realistic expectations from Backlash compensation.
        The best you can hope for from Backlash compensation is 1/2 a step.
Divide the calculated figure by 2 and if you get better than that then you are like me, lucky.

Measuring tools
For this video I purchased a Digital Dial indicator. Up until now I have borrowed an analogue one but for this I decided a digital display was easier to read.  I have put a link below showing the dial indicator I purchased for this video.

Ebay Affiliate Links. By using this link a small commission is paid to me at no additional cost to you. There are many such dial indicators on the market. The seller who sold mine no longer stocks them but here are some similar ones.

Dial Indicator

Magnetic Dial Base

Macros For UCCNC and Mach3
Thanks once again to John Revill for his work in making Macros for UCCNC and sharing them with us. Over the last few weeks he has made and shared several Macros that I am excited to be sharing with you soon. It is thanks to his Backlash measuring Macro that I was able to easily measure my Axis backlash and was inspired to try and replicate it in a Mach3 macro.


Mach3 Macro

Installing the macros and running them is basically the same for both Mach3 and UCCNC.
It is surprising how similar these control systems are in their programming and us.
Just drag and drop the macro into the macro folder and Type M1040 into the MDI command line. If you find you already have a macro M1040 or want to call it something else just rename it as M followed by a number eg M666
So long as it isn't used for something else it should work for you.

The results
John sent me some photo's that illustrated the improvement he experienced by setting up Backlash compensation on his Stepcraft machine. The Laser really shows the backlash and I can see how this will make using the laser much better in the future.

Before Compensation applied 

After Compensation applied

You can see the lines are now aligned correctly compared to the before shot where there is a definite comb effect

How noticeable the effect will be in normal machining I don't know but I envisage it may show improvement in VCarve and PhotoVcarve machining where a fine cutter is used.

Final Thoughts
I have been using my machine for many years without thinking about backlash and I hadn't really noticed an issue. If John hadn't sent me the Macro I wouldn't have givenbacklasha 2nd thought but I'm glad I did.
It makes sense if you have a dial, to spend a little time and check each axis to see how much backlash you have and if you have a problem. Even if the dial you have doesn't have the needed resolution it will still show a major problem on an axis and may also allow you to get most backlash under control. The advantage of a lower resolution dial is it is easier to get those readings looking really good.


Sunday, 21 October 2018

Rack & Pinion or Leadscrew? - episode 221

Dan Zanotti asked me a little while ago a series of questions about my opinion on Rack & Pinion versus Leadscrew. While I'm happy to tell What I have and why I decided to go one way or the other I'm not usually happy to inflict my opinion on them. In this video I try and explain why I moved to Rack & Pinion and why I think that for my machine the combination of R&P on the X Y axis with Leadscrew on the Z is a good combination. I don't claim to be an expert on drive systems, I'm just a hobbyist like you.
In this video I start to explore Backlash which by my reckoning is the only real difference between the 2 systems that might make you think twice about Rack & Pinion.

Click to watch

when trying to decide between the various drive systems cost can play a big part in your decision. It was probably the biggest factor for me because I had to import either Rack or Leadscrew and postage was the biggest factor. For a machine like mine I would have needed a 6 foot leadscrew or a 4 foot Rack and the shorter the package the cheaper it was to send. Rack has the advantage that if in the future I need a longer rack I can easily join it while with leadscrew I would need to replace what I have with something longer. Another issue with sending long packages through the mail system is then could easily get bent. A bend in a leadscrew no matter how slight can be difficult to remove while straightening a rack is easy. the disadvantage of Rack is i needed to buy the drive plate though it is also possible to make one if you know what you need. They are not that complex.

Something I didn't really cover in the video is the resolution of each system. By that I mean how many steps per unit each system is. In my case the leadscrew has 4 times the resolution of the Rack & Pinion drive but when you consider that each step on the R&P is 0.013mm or 0.0005 inch then that should be all the resolution I will ever need. We are not building parts for NASA and the wood we use changes dimension by more then that depending on whether it is a wet or a fine day. 

Measuring tools
For this video I purchased a Digital Dial indicator. Up until now I have borrowed an analogue one but for this I decided a digital display was easier to read. the resolution on the dial far exceeds the machines capabilities. I have put a link below showing the dial indicator I purchased for this video.

Ebay Affiliate Links. By using this link a small proportion of any sale is credited to me at no additional cost to you. There are many such dial indicators on the market and this is just the one I chose.

Dial Indicator

Magnetic Dial Base

Macros For UCCNC and Mach3
Thanks once again to John Revill for his work in making Macros for UCCNC and sharing them with us. Over the last few weeks he has made and shared several Macros that I am excited to be sharing with you soon. It is thanks to his Backlash measuring Macro that I was able to easily measure my Axis backlash and in the next episode we will explore Installing  the macros then using them to eliminate system backlash.


Mach3 Macro

Thanks to John's easy to follow Macro writing I was able to create a Mach3 version of the Macro that behaves the same. My first Macro written from the scratch. These are posted here for anyone who wishes to use them to measure their backlash. In the next episode I will be demonstrating how to install and use them so don't worry if you cannot figure them out right now.

Well that's all for now so until next time


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.

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

Toyota surf 1998   

Toyota Corolla  1996


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.

A great video of a see through Thein separator in action.

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


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.


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.

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

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.

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

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

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

If you wish to read a bit more about it then have a look  here

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.

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.

2017 Screenset

If you are interested in the Screenset mentioned in the video you can find it here.

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.

United States supplier of UCCNC and motion controllers
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.


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

2D model
Saved as a DXF file

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

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.

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.

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.

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.

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.


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.

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.

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.

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.

Until next time