Thread: Wobblycogs CNC Mk1
Btw, for me it all started about four months ago.... I was simply sitting thinking that it would be quite nice to be able to see the cut taking place on the router table, like one can see when making hand held router cuts.... And I started thinking "upside-down" router tables, and then there was simply no turning back...
That one single thought started my downfall ;-)
Funny you should say that as I was just looking at steel prices. I'm favouring aluminium because it's flatter and I may at some point move over to profiled rails. I saw a discussion on self levelling epoxy earlier today which I've put to one side for later (got to get some work done today), that could be a solution.
Btw, for me it all started about four months ago....
I haven't tried this but I've been thinking about it. The supported rail (at least the stuff I got from chai) has a series of machine screws(red) that bolt the rail to the support from below. Maybe these could be replaced with slight longer ones(blue) and bolt through the extrusion, support and into the rail.
Oooh steel, the build begins today . I'm hoping that's not all mine, I've already got more angle brackets than I know what to do with! Good to see it supporting it's own weight on what it probably about a 3m over hang though, I think this frame might just be strong enough :-). Cheers for to the update.
That's a cunning idea with the bolts asbo (and I like the drawing). Some careful planning would be required to get the bolts in as well as a long socket wrench and some careful hole cutting on the opposite side of the extrusion where it looks fairly weak already.
It's very similar to this one:
You could try using a carbide cutter, since 6mm is good at 13000rpm and 8mm is good at 9700rpm. Probably best to try 6mm as there's then more margin for error on the feedrate.
Yeah...don't use extrusion, or add a 10mm plate. The plate is a good idea anyway to reduce local deformation (spread the load).
Linear guides are much stronger than round rails and just generally better - you wouldn't regret it. However I'm confident that with your current design you could cut aluminium quite well, so it's not a necessity.
Problem is the accuracy of steel box section compared to aluminium box, or extrusion. If just using round rails you'll probably get away with it, but it would be hard to mount linear guides on steel box section without entertaining self levelling epoxy.
(Oh just noticed Wobbly said that in the next post!)
It doesn't really tell you anything. With a CNC machine we're not worried about the material failing/passing it's elastic limit, we're instead concerned about making sure it doesn't deflect by a few tens of micrometers. In the image that will probably be bending at least a milimeter.
Last weekend, in the pouring rain, I collected the steel for the base from Neil who very kindly sourced it for me and cut it all to length.
It was all covered in a good coating of oil which has been doing it's best to get every where this week so I turned it in to a somewhat cleaner pile of steel by rubbing it down with a degreaser.
After spending an hour or so cleaning it I decided to get a couple of rust spots off with a wire wheel which is when I discovered that I'd actually only managed to get a light surface layer of oil off, there's a much heavier oil still on the steel. My question therefore is this: how clean do I need to get the steel in order to paint it?
The image above shows a very clean piece at the bottom and a pieces that have just been degreased above. I'm sure the bottom piece is clean enough for paint but are the other pieces? If I've got to get all the oil off what is the quickest method as wire wheeling it all will take ages.
Some good news though. I've tested a couple of the long rail pieces of steel with a reference straight edge and they are fairly close to straight <0.5mm in 600mm.
BUILD LOG: Wobblycogs CNC Mk2By Wobblycogs in forum DIY Router Build LogsReplies: 113Last Post: 10-02-2015, 12:37 PM