Comments sought on new build: A CNC Router for RC Gliders and Planes

[njhussey]

Well doesn't time fly....

Not done anything for ages as life has got in the way (family bereavement, relationship split up and new one developing etc. etc...) but I'll have funds available soon to get all the components so should be able to push ahead. Think I've come to the last (famous last words) iteration of my design. Quick animation of the design is on YouTube, link below.

[WandrinAndy]

Welcome back Neil. I like your most recent design.

[kingcreaky]

glad that despite all your other challenges your still eager for some more... :D cant wait to see the build thread

[njhussey]

Cheers guys!

Once my Mum's (now half mine) house sells (exchanging contracts in a week or so) then I need to buy a 9' x 6' shed which will take 2 weeks to be delivered so the SBR20 rails and RM1610 and 1605 ball screws and BK/BF ends and NEMA 23 motors and drivers will all be ordered at the same time so they should all arrive at about the same time.

A couple of clearer jpgs below...

[kingcreaky]

very similar design to mine... surely you'd be better off just buying mine? :-D

[njhussey]

If I had a big enough shed I would!! Only in rented accommodation (moving from Hereford to Gloucester) so no where to put a big machine like yours :(

[njhussey]

Just got another bargain bit of Ali on fleabay...20 mm Aluminium Plate | eBay

Might have to think about re-designing my router now to take into account the 20mm thick Ali

[njhussey]

Guys, I'm now in a quandary as to which direction to go in my build. I'm going to have to have the router in a shed (10' x 8' it's grown since my previous post as I've been looking at how much "useful stuff" I've recently acquired!!) so space will be at a premium. As I'm mostly going to be cutting balsa, 3mm thick ply, the odd bit of plastic and thin Aluminium (for control horns etc.) do I go for a bigger design I've been working on or stick with the original design? The original design gives me 700mm x 300mm cutting which is ample for what I need it for (not thinking of future expansion though) with 1000mm 20mm rails and 16mm ball screws and the new design gives me 995mm x 500mm with 1300mm 20mm rails and 16mm ball screws. I've been considering also mounting the new design vertically to save space (after remembering Jazz mounting his, almost, vertically.) For the original design I've already fabricated the base but seeing as I have access to getting hold of cheap steel through work, fabricating a new frame will not be that hard or costly.

I'd appreciate your thoughts as I'm in two (possibly more) minds....

[JAZZCNC]

I've been considering also mounting the new design vertically to save space (after remembering Jazz mounting his, almost, vertically.)

If your space challenged then it's a no brainier to me go vertical. There's no down sides only gains, space being the biggest gain.
My machine mainly (99%) cuts aluminium and other than the space saving the other benefits are below. Wood cutting will be similar and possibly better with vacuum for chips.

Better quality of finish due to gravity helping to clear chips.
Much Longer cutter life due to less re-cutting chips, over 50% less wear.!
Greater DOC can be used for roughing again due to less heat and work re-cutting chips.
Less air required for blown air/mist cooling again due to gravity and less chips to clear. Down from 50-70psi to 10psi and obviously much less volume of air required.
Less chips flung around shop again due to gravity and cut chips being cleared more efficiently so not getting re-cut and thrown about with 80%+ falling into bins below machine.
Much easier access and loading/clamping of material due to bed being directly in-front of you, no more back aching bending over fastening material.
Better access to spindle and tool loading.

Has you can see other than the major space saving there's quite a few other decent quality benefits and I can honestly say there's been NO down sides.

Yes there's things I've learnt from being vertical about design that I'd build into a purpose built vertical machine. These would mainly deal with lessening chip collection on various surfaces.
The Z axis would be one area I'd look at and build more shielding around. Ball-screw bearing blocks would be another and I'd build shielding to stop chip collection.
Both of these are only minor things and don't affect the machine in anyway also my machine has NO protection of any kind for belts,ball-screws so they would be things I'd do anyway if was building again and it was horizontal.

The other thing I'd do with MY particular machine is raise the whole thing up higher than it is now.?
At the minute it's just in the same spot it was when first tipped up, sat on same axle stands. This means the bottom area of the bed lower than I'd like also the gantry when parked at top is not quite above head height and I bump my head on it when removing material. Also it's just makes fitting tools into spindle a bit more awkward than could be.
Both of these things are Still much better than when horizontal but if machine was 12" higher they would be perfect.

Now before folks comment on material holding etc other than requiring holding on first placement until clamped then it's absolutely no different to when horizontal.
This initial holding is easy over come with a simple temporary holding shelf I slide into position to place against material edge, which I then slide out the way while cutting. The slight incline of bed then holds it hands free against bed while I clamp or screw it down.
Just like when horizontal both cut parts and waste material needs to be clamped for safety's sake. To be honest it's actually safer regards waste because it mostly falls away from cutter and off the bed so with thought about placement of material cutting entry IE: always starting/exiting at top then there's far less chance of material being pulled back into cutter. That said I also have and do fasten waste material has it's just best practice.

Hope this helps.!

[njhussey]

Jazz, in your opinion would the router be better at a slight angle (15° in this case) or at 90°?

I can see the slight angle as better for work placement as the work will "fall" against the bed and the chips will still fall away into the collection tray at the bottom. I've added some sheet steel sides (that might need more support to stop resonance) so those will stop the chips from being flung all over the place. Just need to work out some shielding for the ball screw lower bearing mounts, and the stepper mounting arrangements and a few other details and I should be good to go I hope?