Re: 5'x3' Ideas and build.
I'm not 100% certain but I believe the purpose of a spoil board is to get spoiled by chopping into it either accidentally or on purpose. When your spoil board is spoiled past being able to use any more how are you going to change it for a new one without dismantling the whole machine?
Re: 5'x3' Ideas and build.
Hi D.C.
Yeah, I hear you on that one - it's not ideal, but I'm going to be clamping a thinner bit of ply between the work and the spoil-board and cut into that rather than the actual table surface.
Cheers.
w./
Re: 5'x3' Ideas and build.
Quote:
Originally Posted by
Wal
X Axis driven by 2x 20mm ball-screws with a lead of 5mm driven by a NEMA34 motor connected by cam-belt/pulleys.
Y Axis driven by a 16mm ball-screw with a lead of 5mm driven directly by a NEMA23 motor mounted to gantry side-plate.
Z Axis driven by a 12mm ball-screw with a lead of 2mm driven directly by a NEMA23 motor.
1. The first plate will act as a mount for the linear bearings riding on 20mm supported rails (TBR20 from Zapp) mounted to 80mm aluminium extrusion and will also act as a brace
From your selection of ballscrews and bearings it appears that you are planning on ordering them from England? If you want to save money on them then linearmotionbearings2008 on eBay offers any size you need if you send him a message, along with fast service. I'm not sure if he has TBR bearings still, so you may have to use SBR. TBR are stronger than SBR, but you could probably compensate for that by just using one size bigger, i.e. SBR-25mm.
Using 20mm ballscrews is only beneficial on the X-axis, of a router, if they are 10mm pitch. You can get 10mm pitch, 20mm diameter, ballscrews from China, but not on eBay. If you used RM1610 the critical speed will limit your rapid feedrate to about 6-7m/min, but that's still respectable for this size machine. To get any more is expensive. See this post.
Most people use RM1605 on Z, but if you want to use something smaller (e.g. RM1204) that would work just fine but there isn't really much point unless you're very short for space.
20mm is plenty of thread engagement for M8 in aluminium.
Re: 5'x3' Ideas and build.
>Wouldn't an easier solution to your 25mm dia Ali bits you're painfully cutting out if plate have been to buy 25mm round Ali, cut to length, mark the centre and drill?
Maybe, but I don't have a metal saw - at least this way I can be sure that each spacer is an identical height - buying stock cut to length is always a bit hit and miss... The guide bit drills the centre hole too! Bonus.
Yep, it's a pain - but on the next batch I'm going to try drilling a guide hole straight through, cut from one side, flip, re-align and from the other side. It's the swarf not rising cleanly out of the cut after 15mm or so of depth that's making this job a pain - flipping the piece should solve the problem. I can only hope!
Cheers.
w./
Re: 5'x3' Ideas and build.
>the single 15mm Y axis (or I think you call it the X axis) plate could do with stiffening as I don't think it will resist twisting very well, especially if the Z axis is at max travel.
Do you not think that the plate that it's bolted to (which sits horizontally behind it) would be enough? When the Z is at max this is the part that's going to be taking the brunt of the forces - hmm... Will have a think.
Cheers.
w./
Re: 5'x3' Ideas and build.
>Cutting from both sides.....ooooooo good luck with that, I can never get cuts to meet in the middle doing that lol
Hehe. Yep, I know what you're saying. Luckily these spacers will be hidden from view... ;)
w./
1 Attachment(s)
Re: 5'x3' Ideas and build.
Not sure how you're doing your Z axis but if you put some bracing across the top it will stiffen it right up, something like this....
Attachment 7724
Probably need to put a brave in between the top and bottom in the middle to stop vibrations too...