Saturday, 29 July 2017

Keyholes - episode 156

It's time to have a peek into keyholes.
They are very useful when it comes to a method of hanging projects on the wall but there are more useful than that. The slots we use for out holddowns on the CNC table are nothing more that Keyhole slots that run the entire length of the table. Used properly these slots can work well but ther do not have the strength of and Aluminum Extrusion but on a small machine they could work OK. I used a Keyhole cutter to cut slots in my router table for fence adjustments and they work very well.

Back to Keyholes for mounting projects to walls.
Not many CAM software packages can create the required toolpaths but VCarve Pro and Aspire can by the use of Gadgets. There is a gadget for Keyholes and it created the necessary toolpaths for cut them. Keyhole toolpaths are different in that the require the cutter to plunge the full depth into the material and them move along cutting a slot under the surface. A small slot is cut by the shank of the cutter. It then needs to reverse back to the original entry point and exit using the hole.

 Click to View video


Keyhole cutters come in varing sizes and designs but the most common is the basic L or T shaped cutter but this by no means the only shapes they come in.


They all have a couple of things in  common. A large blade at the bottom and narrower blades above it to allow it to undercut the surface. In normal theses cutters are put under a lot of stress because they cannot clear the cut material so take it slowly.
While the Bottom blade seem to come in standard 3/8" and 1/2" the upper blades seem to come in several sizes. 
3/8" Lower with 3/16" upper or 1/4" upper
1/2" Lower with 5/16" upper or 1/4" upper
There are also metric versions of these cutters of very similar size so choose carefully what you buy. As with all cutters the price varies considerably froma couple of dollars to $50 or more. Given how often you are likey to use a keyhole cutter I would tend to get the cheaper one ans wouild probably be lucky to blunt it and remember those cutters can be sharpened easily.
The one thing you must watch out for is the maximum depth of cut which is determined by the overall length of the cuttinb blade. This will be the large and small bales combined height. Do not exceed this or you will break the cutter.

I have created some Gcode to use for the cutting of keyholes to hang projects on the wall. Please read the READ ME fole included in the zip files below to make sure you understand the requirements and the risk of using unknown Gcode.

Imperial Keyhole

Metric Keyhole



 Where to purchase cutters

These types of cutters are available from many suppliers so pick the supplier that works best for you.

Please note that by using the link provided to visit the Ebay site I receive a small commission on any purchase you make at no extra cost to you. The link will provide you with search results for Keyhole cutters so shop around and find the best deal for you. If you do use the link then thank you for supporting my channel and remember it costs you nothing.


 Keyhole Cutters

Many thanks for visiting and I will catch you on the next one.


Sunday, 23 July 2017

10000 Subscribers - episode 155

A big thanks to you guys for supporting my channel.
I has now reached 10000 subscribers and to celebrate this milestone I have made a Play button with a difference.
I Couldn't have done it without the support of you guys and am honored that you have taken the time to watch my videos and subscribe.

To celebrate this Google sent me an animated GIF to celebrate but I thought I would make something a little better. This is what I came up with.

Click to watch Video

This is the first tablet I purchased many years ago and don't really have a use for it so I thought I would use it for this project. I think it cake out pretty good.

Once again thank you.


Saturday, 15 July 2017

Feeds & Speeds - episode 154

Let me start by saying that I don't claim to be an expert on feeds and Speeds but I have learnt a few things over the years.
  • I know they are important to ensure a decent tool life and the finish on my projects.
  • I know that when abused in the extreme they will cause my cutters to break if my feed is too fast or burn my work and dull my cutter if the feed is too slow.
  • I know that even if you calculate your feedrates using manufactures data it will still depend on your machine as to whether they are right for you.
  • In short, it's a black art.
Click to watch video

Onsrud catalogue

The Onsrud catalogue is the only reference material I found that had Chipload information in it other than the Apps I mentioned in the video. I include a link to the catalogue as it may be useful in determining feedrates for similar cutter types.

US Router Tools App

Before using this App please download read and understand the following documentation
These are generic chiploads and need to be traeted as starting points not Gospel.

Cover art 



Vortex Tool Co. Router Bit Selection Guide

Cover art

This is an interesting app with built in calculators and a tool recomendation guide based on your selected material and machining use.



I hope you find this useful and it will help when you need to figure out Speeds and feeds for your next job. Remember to treat these as starting points and use your best judgement to determine what is right for you. If you are happy with the way your machine cuts and you are not destroying router bits then that is what matters in my opinion.

Until next time