New build with recycled parts on a ridiculous budget 120cm*60cm work area

[Desertboy]

Already budget is out the window ha ha ha.

I bought a pair of 1.5m of linear rails with 4 blocks and a 1.4m ballscrew with couplings, mounts, etc.

Spend is ~£250 now but will need to buy 2 900mm ballscrews for the x axis and need to sort z axis but I think I can do that cheap.

That will then leave a router/milling spindle but lol lets get the X,Y & Z working.

[Desertboy]

Bought 2 1m ballscrews now so I have

A strong aluminium frame 1.6m*1m made with heavy duty profile
2 supported rail 25mm slides (With new bearings) will cut to 100cm
2 linear rails with sliding blocks (HWin) 1500mm long with 4 blocks
1 Ballscrew 1400mm long RM1605
2 ballscrews 1000mm RM1604
The fittings for the ballscrews, motor couplings, etc.
Most of a z axis (25mm smooth rod & bearings, 20mm ground ballscrew travel 20cm) I will need to decide how much travel I need and cut down and machine to fit.
2 nema 23 motors (I have these working)
Arduino Uno, CNC shield
Nema 23 mounting plates
Probably more stuff


The budget has been taken outside like old yellow and a bullet has gone in it's head. I am now working on a budget that I bought an xcarve (Which I was seriously considering but in the end decided I could build something a lot better for a lot less and also the satisfaction of building your own and of course I have a lot more wiggle room for upgrading.

Now is the waiting game as I ordered cheap ballscrews from China to get it working (C7) this will be fine I'm sure for my first cnc. When I get some cash in (I already have some jobs for the cnc I outsource at moment.) I will upgrade the ballscrews, cover the frame in 5mm steel (The Y axis will get only 3mm to keep weight down). I also will swap the 2nd hand supported rail for new from zapp.

I now need a spindle but totally wiped myself out financially.

I have some work for this machine so when it does work I will use the money made to upgrade the machine (Looking at slides, ballscrews and electronics also encase frame in steel) and I need to build an 8*4 which will be for wood based products only.

[Greeny]

Looking like you're powering forward with the parts. She'll be cutting in no time ��

1605 &1604 ballscrews might be problematic though.
You're going to have to gear them to spin very quickly to get any reasonable feeds for cutting mdf/wood.
You may experience problems with whip:
On the 1605 1400mm the calculated critical speed is about 1000rpm which equates to 5m /minute.
On the 1604 1000mm the calculated critical speed is about 2000rpm which equates to 8m /minute.

You may be happy with those feeds or may able to exceed the critical speeds, but just wanted to highlight it.


Cheers

[Desertboy]

Hi Greeny thanks for the reply,

This is my first CNC so making it up as I go along. I have a job to do with this machine (At moment I sub contract but am tied into a contract so have 3 months to finish this if I choose to fullfill it myself.) when it's done I intend to build an 8*4 rack and pinion machine for ply and beef this up to do harder materials. Mostly aluminium but occasionally a steel bracket (Mostly building more machines for me personally). I'm somewhere between home user and pro but I get a real kick out building it and am interested in the automation ;)

Like everyone on here I want at least 6 machines in the end 5 of them I will build ;)

3d printer (Already have)
cnc miller/router
cnc router 8*4
laser cutter
vacuum former (Have vacuum pump and air tank)
decent vertical wall saw

[Greeny]

Hi Desertboy,

Sounds good.
All the best with your build, will be watching with interest.

Cheers

[Desertboy]

Greeny out of interest how would you have drive this?

Also for 8*4 how would you drive it? I was thinking R&P for 8*4.

Originally I was going to try and drive this belt and pinion but I knew I was building something special so ballscrews seemed the only choice I want a very capable machine and I'll build the 8*4 for speed and production as 90% will be ply/mdf style products or real wood.

[Greeny]

Although i have a lot of experience using big cnc machines, I don't really have the building experience to offer good advice,
but as long as you bear that in mind here's what i would be looking into if i was thinking about a machine that size.

A ballscrew for the 4ft axis , either a 2010 or 2020. Nema 23 3nm.
The 8ft axis probably 2510 or 2520 fixed ballscrew with 2x rotating ballnuts and 2x nema23.
I would personally only consider R&P if budget can't stretch to rotating ballnuts as they are pricey.

Here's a few relevant threads you might like to peruse.

http://www.mycncuk.com/threads/3340-...n-ideas/page14
http://www.mycncuk.com/threads/10219...tart-8x4-build
http://www.mycncuk.com/threads/10865...concept-review

Hopefully someone with more building experience will chip in.
Cheers