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Robin Hewitt
30-08-2008, 11:48 AM
In my junk pile I have a Borries engraver. Has precise X Y screws at the top and a T slot bed at the bottom. There's a handle to wind the top up and down. It's old, 60cm high 33cm wide by 34cm deep (approx) and weighs like it would need collecting. Comes with a big controller box and a stack of manuals. Presume the pneumatic engraving heads could be replaced with a light rotary cutter but not by me.

I'm getting too old to do anything with it. Looks too useful to throw away, might be just what some budding CNC hack on a budget might want. Forty quid.

If anyones interested I'll post some pics.

Robin

irving2008
30-08-2008, 02:12 PM
put some pics up Robin...lets have a look

Robin Hewitt
30-08-2008, 04:46 PM
I think the active area is only 100mm square, but as it's designed to drag a stationary carbide tipped cutter through metal with great precision, it is Robust. I think the steppers are rated 70v 6A. Full X Y bellows so it shouldn't have too many spiders inside :D

Could be great for cutting pcb's.

Robin Hewitt
30-08-2008, 04:50 PM
Made in 1996, there's a plate on the back :D

Lee Roberts
31-08-2008, 02:07 AM
That would make a good little weekender!, are you going to do it up ?

Lee Roberts
17-10-2008, 01:13 AM
Did you ever get this going?

Robin Hewitt
28-10-2008, 01:38 PM
Hi Soapy

I think it's sold. I got a PM so I can't say who :rolleyes:

Probably wants to cut bank note printing plates or something like that :D

best

Robin

irving2008
20-11-2008, 03:23 AM
Hi Soapy

I think it's sold. I got a PM so I can't say who :rolleyes:

Probably wants to cut bank note printing plates or something like that :D

best

Robinlol...

Well I am the happy recipient of said beastie, now christened Boris. I picked it up from Robin this evening... the closure of the A23 on the way back added an hour and made it a 5hour 200mile round trip - the petrol almost cost more than Boris!

So when I got home it was with some concern I had a quick scan of the manuals and decided to open the box (since Robin had already taken the money - duh, showing my age there)

Anyway, heres three pics of the insides...

What we have are a Pacific Scientific single stack Powermax II stepper (0.8Nm) belt driving a 10mm pitch 12mm dia ballscrew for the X-axis (upper screw) and a double-stack version of the same stepper (1.5Nm) driving the belt/screw for the Y-axis (lower screw). Resolution according to the manual is 0.02mm (10mm/rev/200 = .05mm half-stepped is actually .025mm, but thats good enough for me!) The steppers are 4.6A bipolar parallel. Pic 3 shows the Y motor and the end of the X slide (in shadow above). All the ballscrews are supported in bearings.

Working area is 100 x 100mm.

The controller unit contains a pair of stepper driver boards (9.1A max, full/half step) opto-isolated inputs (step/direction) and a power supply rated 70v 9A plus some other rails for the electronics. It shouldn't be too hard to get EMC to drive this :D

There is no Z drive as such. Boris has a pnematic hammer that vibrates at 100Hz approx and marks the work. 'space' between markings is simply acheived by turning the air off with a solenoid valve (the thing with the CE mark in the first pic). The whole X/Y assembly is supported in the Z-axis on 2 x 40mm round rail slides with a 3mm pitch leadscrew (doubt its a ballscrew tho) with 140mm motion driven by a handle for setting the z-position and fitted with a revolution counter calibrated in tenths. In operation you would place the item to be marked under the scribe, wind it down til it touches and then wind back 1 or 2 clicks on the counter to clear the work surface. In the manual it suggests that the software can be programmed to pause for the operator to wind the Z up and down to avoid obstacles!

It wouldn't be hard to fit a stepper in place of, or alongside, the handle.

I am thinking that for PCB milling/drilling a small air spindle would be ideal, since there is already an air supply/regulator assembly. There isnt really room for a motorised spindle in there unless the motor was slung alongside the spindle below the X/Y axis somehow. With the X/Y unit at its maximum height there's 210mm of clearance to the table, and for PCBs you need the length of a 1mm drill in a collet plus a few mm for the sacrifical plate clearance, say 50mm all in.. so a 150mm long spindle is a possibility (theres about 50mm clearance internally).

Its a superbly engineered piece of kit and I'm fairly confident it can be repurposed as a PCB milling machine relatively easily...

So am I happy?... what do you think :D:D:D

ps Robin, thanks for the cuppa. And I am in awe of both your plasma cutter and injection moulding machine - they are superb examples of engineering skill I'm not sure I'd even begin to consider... hope to see them both working one day!

Robin Hewitt
20-11-2008, 11:23 AM
I discovered I was crap at explaining things when faced with someone who could actually understand. Probably because I've never met anyone like me before :D

Boris had to be somewhat disassembled to fit in the irving2008-mobile because he drives a gas guzzling, bird magnet. He got stuck talking cars to a pair of drooling wives, but I got the impression he's used to that :rolleyes:

Silly idea, but could you turn the whole stepper assembly upside down on the column, fit a table to it then use the cutter pointing vetically down in to the PCB?

1: You'd have a unobstructed view.
2: You could support the cutting pencil at it's business end.
3: The bellows would stop the crut getting in to the works.
4: It would look a lot prettier.

irving2008
20-11-2008, 12:25 PM
I discovered I was crap at explaining things when faced with someone who could actually understand. Probably because I've never met anyone like me before :D:D made sense to me tho ;)


Boris had to be somewhat disassembled to fit in the irving2008-mobile because he drives a gas guzzling, bird magnet. He got stuck talking cars to a pair of drooling wives, but I got the impression he's used to that :rolleyes:let me hasten to add they weren't both Robin's... I'm fairly sure of that. Its not much of a bird magnet although I do have to clean the fabric roof off quite a bit in the spring :eek:. Hey, it fitted didn't it and got home in one piece (well 3 really!)


Silly idea, but could you turn the whole stepper assembly upside down on the column, fit a table to it then use the cutter pointing vetically down in to the PCB?

1: You'd have a unobstructed view.
2: You could support the cutting pencil at it's business end.
3: The bellows would stop the crut getting in to the works.
4: It would look a lot prettier.
Funnily enough I was thinking that. It could work, the only issue would be the turning moment on the slides when working to the edge of the table, but for PCB milling the forces are relatively low. I note that the current stylus is offset about 25mm from both X and Y slides and they would experience much more moment when marking than a PCB milling operation. A table made from 150 or 200mm square of 10mm ali mounted on a 50mm square block would probably work well... Effectively that would create a knee mill as the table would move to the cutter which would be static and mounted on a frame bolted to the sides of the upright column.

irving2008
20-11-2008, 11:55 PM
Well it steps :) but its incredibly noisy. Some tuning required I suspect.

Robin Hewitt
21-11-2008, 01:12 AM
Well it steps :) but its incredibly noisy. Some tuning required I suspect.

My first guess would be an electrolytic has dried out. I have performed miracles in the past simply by changing electrolytics.

You don't but an electrolytic you only rent it :D

irving2008
21-11-2008, 01:30 PM
My first guess would be an electrolytic has dried out. I have performed miracles in the past simply by changing electrolytics.

You don't but an electrolytic you only rent it :DI'll get the scope on it over the weekend and see how the supply rail is holding up... Cant be far off tho as as soon as power is applied the axes lock solid. I need to get a prototyping Euroboard to allow me access to all the signals on the backplane, I was only bit-banging the step-lines individually using some wire poked in the holes in the socket to connect to the BOB. Worked tho :D