New Machine Build- CHESTER MODEL B 3 IN 1 BOTCH JOB

[mung]

I thought I would post some pics of my build, I started at the weekend. I am going to try to do the job at minimal cost and time. Budget is below £200, I hope to finish first version in a month, then make improvements from there.

I am a beginner, only metalworking as hobby for a year and most of my stuff is a botch (which I blame on the awful machine ))) .

I hope to post some pics, video, and maybe some text about my ideas and what I have done.

Don't expect too much, I am trying for an evolutionary approach, botch then improve.

Very quickly what I did this weekend:

1) wired up and installed variable frequency inverter for main motor.
2) made stepper mounting brackets for X, Y, and rotary table from 100x50x5mm alloy extrusion.
3) played with linux cnc emc ubuntu distribution.
4) tested pacsci stepper that I got from ebay.
5) tested some other stepper drivers.
6) butchered all the atx PSUs I have lying around (have heard switching psus are not good for stepper drivers but thought I'd give it a try anyway).
7) mounted most of the PSUs in an atx case.
8) thought about how to remove backlash in the lathe
9) butcher some HTD pulleys from a HP laserjet to connect steppers to lead screws
10) took loads of pictures and some video

May post some video when I get time though its not good so I may not bother.

[mung]

ATX pc case with 2 AT and 2 ATX PSUs stacked to give 48volt supply for stepper drivers, I had these lying around scrap.


X axis mounted

X axis mounted from above (this is just test fit further work needs to be done)

X axis and the rotary table mount on the bench.
X axis mount was made by hand (i.e. not on the lathe or mill) in about 30mins, cut section of alloy extrusion about 200mm long on band saw, mark out and centre punch mounting hole positions, used battery hand drill to drill 9 holes. It just seemed easier to do by hand than setup on the lathe as it would not fit in the vice.

Rotary table stepper mount was machined on the mill, as the mount holes needed to be fairly accurate, took about hour and a half (though probably could do in 45mins second time, as I keep having to change drill bits).

The drive pulleys for X axis came from a laserjet printer and were filed down.
I may go to davall or RS for some proper HTD pulleys in the future depending how the scrap ones workout.

The drive belt came from ebay for £1.59, HTD M3 10mm width belt

The steppers came from supplier who gave best price they are old stock size 34 2Amp 3Volts unipolar and work out at £8 each (had to buy case of 6)

The drivers I got from ebay 2 (2.5Amp 45volt) for £17(8.50 each), another 1 (3.5Amp 55Volt) for £18, and a pacsci 34 long series motor and driver (with 240volt ac supply) for £45.

I feel I paid too much for most of the stuff I got from ebay (there always seem to be idiots with too much money bidding against me!). Most of the stuff is used and probably found by someone on a rubbish dump.

[mung]

YouTube - stepper motor test

YouTube - stepper motor test

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I had a little trouble working out how to access the serial terminal on the linux cnc live distribution as I had only ever used minicom and that was not available.
So after a few googles I found some other serial terminal comms programs, went back to the cnc pc and tried each on the list. The only serial terminal prog that is available on the emc distro (as far as I know) is "screen"

screen /dev/ttyS1 9600

(access the ttyS1 at 9600 baud)

So just a quick vid showing how I accessed the pacsci 5445 Microstep Indexer/Drive via the serial terminal in linuxcnc emc ubuntu live cd distro.


More videos available once I have time to upload them to youtube.

I think I have some vids of:

a)points on the lathe mill that are total **** and the manufacturers should be embarassed of
b)wiring a VFD to a three phase motor
c)general workshop
d)rotary table stepper mount
e)?????

Have not looked at it all yet and most is probably poor quality (I always seem to end with two option doing a poor quality job or never having time to finish the job)

YouTube - screen tty to stepper motor driver

YouTube - screen tty to stepper motor driver

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YouTube - stepper mount for rotary table

YouTube - stepper mount for rotary table

[mung]

So total fiasco this weekend I was hopeing to get a couple of axes test fitted and run the motors using linux cnc.

But after a quick look at the system I decided the original plan was a bad idea, and felt it would be more productive to blow four channels of my parallel post.

So to achive the new goal I had to carefully drop a screw driver on to the stepper drivers so that the 36v stepper supply shorted to the step and direction lines to the parallel port.


Anyways I found out a little about linuxcnc axis gui and setting up the parallel interface.

Made a pretty much complete assembly of the Y axis (mounting bracket, motor, pulleys, belt, and tensioner).

made some changes to X axis for longer belt as I realised I did not have suitable M3 HTD pulley for fitting the leadscrew so used a smaller belt.

Made a 5.25" drivebay bracket for two stepper drivers and alterations to the wiring.

Tested the stacked PC power supplys and found that they did not work..... FFFFF.

Machined pulley for X axis.

Some pictures below....


X axis bracket

X axis bracket

X axis bracket

Y axis bracket almost complete

Y axis bracket almost complete closer

Y axis different angle

the steppers, 5.25" drivebay bracket, and wires, foil wrapped motor wire to cut EMI noise.

box of scrap drive components

tapping holes that were drilled for stepper mounting bracket.

offering up the stepper bracket to mark holes to drill.






May add some more latter.

I get the feeling I take too many photos though.

[smallblock]

I used to read a car magazine printed in England. Whenever they found some long lost classic, the article invariably began with " It was pulled from a garden shed which had long since collapsed around it"

[mung]

Originally Posted by smallblock I used to read a car magazine printed in England. Whenever they found some long lost classic, the article invariably began with " It was pulled from a garden shed which had long since collapsed around it"

I think england may be a collapsed shed but there are still a few old classics in it?.

I knew an old stegasaurus that worked at the company, used to go round taking pictures of that sort of thing (think it was for practical classics?, maybe not the same magazine though).

[mung]

I have made very little progress as I am considering how to get a decent power supply (that will run possibly 6 axes at 3.5A 40V per axis) with very very little money.

I made a few more vids and started trying to edit down the larger ones so I can post them.

Adjusted made minor mods and tested the X axis as shown in the vid below:

YouTube - cnc axis test max speed 400mmpm

YouTube - cnc axis test max speed 400mmpm

Will maybe post another vid showing the stepper stalling (test showed max speed of about 400mm per minute), making and assembling the stepper mounting...

Few more pics taken, but I am still behind in posting what has been done as I have not shown a lot of work that was done last weekend. Some pics and posts are not going to be in chronological order.

Considered what the plan for future work will be:

1)Get all steppers and axes assembled and tested.
2)Workout power supply system
3)Look at covers and guards to ways/slides and leadscrews.
4)dismantle and clean all components
5)Final reassembly and fitting fixing backlash problems.


I hopefully have found a way to fix any backlash problems in the leadscrews with very low expense and no machining or special tools. But I think backlash adjustment will be the last thing to do.

Will post more when I get a round to it.

[mung]

YouTube - cnc axis test max speed 400mmpm

YouTube - cnc axis test max speed 400mmpm

[mung]

Just edited this video, was actually done a few weeks back.

YouTube - imo inverter wiring for emc linux cnc lathe conversion

YouTube - imo inverter wiring for emc linux cnc lathe conversion

I get the feeling there will be no work done this weekend as I'm feeling ill, but that should give me some time to edit and post old videos.

[mung]

YouTube - rotary table, cnc, stepper motor, mounting bracket, fitting

YouTube - rotary table, cnc, stepper motor, mounting bracket, fitting