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

[JAZZCNC]

Ok here's things I see with this and learnt from mine being vertical.

The Machine frame, (not holding frame) needs much more bracing esp at the open ends. The 2 short uprights will flex if not braced well, triangulate much has possible.

Chips which fly up will collect in several places on way down so think about covers or deflector guards. Collection areas are:
#1 Against the rails on Y axis so on the top side just in front of rail with enough clearance for bearing to slide by put a short angled deflector/catch plate which they hit first and slide off.

#2 The Ball-nut mounts so again some form of angled deflector plate wrapping over the mount with hole for screw to pass thru, won't hurt to build in a wiper seal has well. Chips don't collect so much on screw but they do around the ballnut where screw enters on top side so this is the target area to keep chip free.

#3 The bottom bearing mounts.! Same deal just some form of deflector guard so chips hit that first and bounce off.

#4 THE BIG ONE . . .Complete Z axis cover needed FROM THE START. While turning 180deg you have lessened the chip collection points BUT they will get in there and the ONLY way is full cover. They are easy made with thin Ali plate and weigh nothing not the prettiest things but very affective. Something Like this


Also while turning 180deg helps keep chips off rear of front plate it will also make it very awkward for when your changing tools.? The way you have it When doing jobs with several tools you'll have to lower gantry to reach spindle properly and that will mean leaning over gantry so will be very awkward.
Much better to raise gantry and access spindle from below, I have my screen setup with tool change position where gantry goes to top and Z axis parks in centre of gantry. This brings me to #5

#5 Not chip related but relates to parking the machine when not used. You want to build in some bump stops at the bottom and when not using park it there to release any tension on motors/screws/belts etc.
On my machine I just have some thick rubber dougnuts with slit in which slip over screws and sandwich between bottom bearing mount and ballnut which i slowly drive upto, simple but affective.! . . But if was building from scratch like you then I'd build in some permanent bump stops, either fixed or flip up jobs.?

#6 Not a biggie but still worth doing else it will annoy I'm sure.?. . . Put the side covers on the inside of frame not outside has again chips will collect and build up, have the inside walls smooth and uninterrupted and chips will slide nice into box below.

That's it for now if spot owt else i'll shout. .Lol

Edit: All the above with exception of beefing up frame work are Minor things and even if left uncovered won't affect machine working properly just annoying and over time will cause premature wear which is easily avoided with simple deflectors or covers.
Don't necessarily need to cover every thing just deflect chips away.!!

[JAZZCNC]

Said I shout up if seen anything else, well I have. . Lol

Looks like you are thinking to use the slotted front gantry style.? Well the way yo have it now it will eventually fill up with chips. .. Doh.
. . Even with brush guards they will get thru.!

The slotted gantry is great because it keeps every thing neat tidy and protected and it will work perfect turned other way just not this way. . .Sorry.!

[njhussey]

Cheers Jazz ill look at the design again and take into account your comments...

This afty was finishing the shed off. Well nearly as got to go out in a bit so had to stop. Its all done apart from the boards on the roof edge at one end but as the boards need altering I've run out if time. Given it a coat of clear preservative so should be ok when it rains. Still needs another couple of coats to be on the safe side.

[JAZZCNC]

Looking good Neil.

I'm a little concerned thou that your going to put a heavy frame of that flimsy looking wooden floor.!! Let me tell you when this machine gets moving around it will Rock that shed so much you'll think Pink Floyd is in there.. Lol

You will Seriously need to strengthen floor and brace the inside walls for the size machine you have planned, honestly can stress the amount of inertia and movement the machine will send thru that shed if frame and structure is not Rock solid will blow your mind.
When my my machine was horizontal and not bolted to floor then on full tilt it would easily walk about the workshop when doing jobs with lots or direction changes.
Even now it's vertical and bolted to Concrete block wall if I put my hand on wall when cutting fast materials like woods I can feel the wall vibrate so your shed walls will quiver like a jelly if not solid.!

[njhussey]

Dean, the plan is to put a second floor of 18mm ply screwed to it and then bolt the machine through the floor and into the base which has 12 4" x 4" posts concreted into the ground. I'll insulate the walls with Celotex and skin it with 12mm ply. This will be screwed to the walls and braced round the top and bottom. Its only a temporary shed/workshop until we move so hopefully it won't shake itself to bits before then!!

[JAZZCNC]

Dean, the plan is to put a second floor of 18mm ply screwed to it and then bolt the machine through the floor and into the base which has 12 4" x 4" posts concreted into the ground.

Ah Ok that sounds a good plan I'd hate for you to tip your new shed over on first job. . Lol

Michael Marino has his machine in similar sized shed which is super organised with shelf's etc and I remember when took it up to him saying about machine shaking shed and stuff falling off. . . . He'd only had crappy merchant dice snail before this machine and think he thought I was joking.!! . . . He soon realised I wasn't when it tried to walk off the bench and out the door. . . Lol . . . . . And that was at half it's capable speed.!!

That machine and gantry was half the size and weight yours will be.!!!!! . . . . Fasten it well.. .Lol

[njhussey]

Ordered one lot of linear rails 1190mm long with 8 blocks on Thursday night, they arrived from Korea today at 8.45am......that's fast...straight through and no stopping at customs (if you know what I mean ) These I'll cut into two lengths, one 750mm long for the Y axis and one 420mm long for the Z axis. Ordered the ballscrews from Chai today so waiting on one more lot of linear rails (1390mm long for X axis) and the ballscrews and then I can start the build in earnest!

[Wobblycogs]

The shed's looking good as are the rails. I got stung for fifty quid and a two and half week delay with the rails I imported, I obviously don't have any luck at the moment.

[njhussey]

I was lucky, not complaining as I've always had the fee (which I don't mind as it's the law) on imported stuff so a bit of a change. You got your steppers and drivers yet? Which ones you going for? I was thinking of the Leadshine AM882 from Zapp and the Nema 23 3.1Nm stepper motors from cnc4you...plus looking at making my own (gulp...) PSU.

[Wobblycogs]

Erm, snap on all items (even where I was planning on buying them) . From what I've read they seem like a good combination of parts. I'd probably have made some purchases by now but I've been looking into getting one of these PMDX-107 for spindle control. I doubt I'll set up spindle control straight away but if I can order the part at the same time as the BOB that would be good. I take it you've seen this thread about building a PSU?