Bloke in uncoverted loft with 3 dot matrix printers says hi

(originally posted on CNC Zone, but replicated here with a little editing since I'm UK based & maybe not everyone here reads that forum)

I've finally got around to building my my CNC

Because I'm such a cheapskate I wanted to spend as little as possible on this.

Ingredients..

6 x Dot Matrix printers - kindly donated from work (they were about to be thrown out - intially I only had three, but the extra three have made a significant difference to how I've rolled out the design) ....excellent for hardened steel rail & the bearings that ride on them...also stepper motors (albeit weak ones) & switches.

Steel pipe (was formerly used as stair handrail at work)...this is for the frame

4mm Aluminium plate (used to be blanking plates to fill in the gaps on the front of computer cabinters). This has proved to be excellent for keeping everything fairly level.

Bought items...

Stepper driver card (I couldn't be bothered to make my own)

Linear rail mounts (a godsend ...the linear rails out the dot matrix printer were 11.94mm...a bit of ebaying found a product called 'sk12' mounts (for 12mm rails) ....these held my rail perfectly! All 12 for about £20 delivered (I'm a Brit)

M8 threaded rod - remember ...I'm cheap.

Roller Skate bearings.

Delrin (to make my own anti backlash nuts)

Some screws/bolts.

I'll be powering from a fairly powerful bench PSU I already have.


Ok, I've only just started the build (two days in), but here you can see the dot matrix printer transport after I'd stripped it out of it's casing (you can make the photos larger by clicking on the main photo within the page that opens).....

http://img16.imageshack.us/img16/643...omments.th.jpg

These are the linear rail mounts (money well spent)....

http://img12.imageshack.us/img12/928...mmentsn.th.jpg

Here's an early shot which outlines the basics of the steel frame (lossely based on the easy CNC mill design - the steel frame will be all welded once everything is finally built & 'lined up').

http://img12.imageshack.us/img12/1238/cncframe.th.jpg


& here's where I'm up to as of today...

http://img12.imageshack.us/img12/365/cnch.th.jpg

http://img16.imageshack.us/img16/511/57487199.th.jpg

(note, the little bit of wood you see at the end of the threaded rod , was just an experiment to try & get the threaded rod level. Also the bright green thing with a red top isn't a sex toy...it's a carton from one of my kids ice lollies, I've got some enamelled copper wrapped around it for a home pickup project - another day!).

yes, I know the stepper is going to be too weak...initially, I'll only be cutting thin acrylic & we'll see where this takes me (I'm using a dremel as a spindle but have my eye on a nice wolfgang spindle!)

Still to do...

mount the motors (I'm still trying to figure out the way to do this cheaply!)

Align the threaded rods with the motors. (M8 threaded rod to 6.35mm shaft - any ideas...remember, proice is a motivating factor here!)


I'll update soon - bear in mind this is my first build (& no plans to follow...making it up as I go along) , I'm not really the mechanical engineering type (more the electronics sort)

Flexible coupling would be ideal.

Quote:

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Originally Posted by HankMcSpank

Align the threaded rods with the motors. (M8 threaded rod to 6.35mm shaft - any ideas...remember, proice is a motivating factor here!)

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Quote:

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Originally Posted by Gary

Flexible coupling would be ideal.

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Do you mean like PVC tubing?

If so, the problem is the 'differing' diameters of the two end I want to connect ....ie M8 rod is erhm, 8mm(!) & the stepper shaft is 6.35mm ....???

PVC tubing is very crude and will not be accurate.
I am reffering to an actual coupling.
Have a look on our website, there are quite a few options, on the bore sizes, and 6.35 and 8mm are standard.

Quote:

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Originally Posted by HankMcSpank

Do you mean like PVC tubing?

If so, the problem is the 'differing' diameters of the two end I want to connect ....ie M8 rod is erhm, 8mm(!) & the stepper shaft is 6.35mm ....???

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Hank

Just do a search on CNCZONE for the Wolfgang Spindle before parting with your money, there have been issues with the bearings allegadley!!!!

Andy

Quote:

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Originally Posted by HankMcSpank

mount the motors (I'm still trying to figure out the way to do this cheaply!)

Align the threaded rods with the motors. (M8 threaded rod to 6.35mm shaft - any ideas...remember, proice is a motivating factor here!

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1: Mount the motors rigidly to the shaft so the shaft supports the motor.

2: Run an arm from the motor and tie it to something solid with a rubber band. This means the shaft has to turn, not the motor.

The motor may wobble about a bit but it's cheap and it's a good solid connection :beer:

You can get couplers from the same place you got the SK mounts from as well Hank ;)

8mm x 6.35mm is not a problem.

Just got round to making a short video of my 'heath robinson' (cheapskate's) CNC making parts for itself (a toolholder)...

[ame="http://www.youtube.com/watch?v=JOAPOP_3wq0"]YouTube - DIY Hobby CNC mill made from Dot Matrix Printers[/ame] (check out the elastic bands holding the dremel to the Z plane ....which is why it's cutting a new proper toolholder in the video!)

It's not exactly rock 'n roll but it tickles me!

Also got to sort out a better way of clamping the material!

I'll get a few photos taken of this machine once this toolholder is finished being cut & mounted (the final part of the five pieces designed in CAD will hopefully be cut tomorrow night), I just need to tidy my workbench a little afterwards!

Total cost about £140...

Stepper motors - free (dot matrix printers)
Stepper motor mounts - free (made from some 4" x 2" that I had lying around!)
Linear rod - free (from the dot matrix printers - about 33cm long)
PSU - not exactly free but I already had a 30V bench PSU capable of 5A.
£85 driver board (couldn't be @rsed to make that myself!)
£8 M8 threaded rod
£5 - drive nuts (I made from a block of delrin I bought off Ebay)
£16 - twelve SK12 mounts (for the linear rod)
£5 roller skate bearings (to thread the M8 threaded rod through)
£10 for 6 x SK16 mounts (for the roller skate bearing turning the M8 rod)
£10 various nut, bolts & screws!

Software - various CAD/CAM/CNC demos (need to shell out for some of this I guess!)

Quote:

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Originally Posted by Kip

It's alive! and working OK......I liked the "Pimp your bubble bath" video better :beer: Didn't have those when I was a kid!

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Wot bath's ? yer did, it's were ya da kept 't coal.

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