What do I need to add a stepper.

Hi Guys.

i have an XJ9512 milling m/c. I'd like to motorize the table in order to get a better finish and save all that winding back and forth. The problem is, I'm no electrician and haven't any real idea of what I need to be able to achieve this.

reading various threads on here there seem to be a lot of you that know about electrics, so I guess what I'm asking is could someone inform me please.

dave

You need a stepper motor, a power supply and a driver.

Outside of that - I am none the wiser, sorry. But this is something I would like to do too. I was a little reluctant to ask as I am not sure I would understand the answer.

What I would really like is someone to come along and show me a shopping list of components. I could probably work it out myself from there.

graham.

Hi Dave, you may want to consider using a small DC motor on the table X axis, many are low cost and run at 12 Volts so quite safe to use, could be direct or gear/belt/pulley connection to your existing feedscrew, just a case of sizing for the power required and figuring out the connection method. 12 VDC controllers are plentiful and very low cost. You would of course need to attend the machine to reverse the travel at each pass, although this could be achieved by using limits connected to reverse direction at each hit.

Going the stepper route would I believe allow better control but at higher cost.

Rgds, Emgee

Dave, Graham,

Some years ago there was an article in MEW on motorizing a tailstock hand wheel. It had all the ingredients you need to make it and could be adapted to suit your needs. I'll try and look it out tomorrow, unless anyone else can come up with the MEW number first.

Cheers

John

It's quite simple to make up a power feed using a surplus window winder motor. They usually come with a fairly large reduction gearbox (worm and wormwheel) so you can drive the leadscrew directly. Mine was a 24V motor and I drove it with a variable 0-30V power supply so I could set the feed rate - you really need that I'd suggest. You can buy these PSUs from the likes of Rapid Electronics and Maplin.

It only took me a couple of hours to make up an adaptor and bracket to couple the motor to the existing handwheel coupling, in place of the handwheel. The main issue is that you can't turn the leadscrew by hand without removing the motor and ideally you'd fit limit switches to prevent damage if you left it running. Mine can be fitted and replaced fairly quickly.

This was for the generic Chinese (Sealy in my case) milling machine X-feed. Not long after this I acquired a Bridgeport clone and the Sealy has been sulking in the corner ever since....

I could post some pics when I get home if you'd like.

Merry

To answet the question as posed

1 stepper/ stepper gearbox combo...suitable torque and size [too small motor even if geared for torque might be too slow)

2 coupling between machine and above

3 stepper driver electronics to suit 1 above..

4 psu to suit 1 and 3 above

5 variable frequency pulse genertor to signal steps [also knob ]..to stepper drive above...

6 forward reverse switch connected to 3 above..

plus swarfproof box etc.

or..cordless drill ---speed control fwd/rev .gear box and torque limit all built in..

Edited By jason udall on 26/11/2013 23:44:53

..... Also good for rapidly winding the mill-head up to the top of the column without effort.

Here's what I did. Avoids the need for a lot of the stuff Jason listed. Depends what you have to hand - I couldn't find a suitable drill driver....

The drive dog was a snug fit on the output gear of the motor gearbox.

I just had one wing nut to secure the assembly. The pillar was quite rigid enough.

The assembly simply swaps out for the hand wheel.

Not pretty but it works. 3 position switch gives forward / stop / reverse. Motor is 24V nominal (ie spends most of its time at 28V) and the PSU was a 0-30V, 0-2A (I think) El Cheapo lab power supply. Sat next to the machine so I could adjust the voltage (speed) and current (max torque).

There is a similar PSU to the one I got currently available from Maplin at about 90 quid. Arguably, with a current limited PSU like this you can get away without limit switches.

Hope this is useful in some way.

Muzzer

This is a 12v clutch and a 12v motor from a car window runs from a small transformer as i wanted it to be low voltage and safe.

it was easy to fit but a few months to get all the bits from eBay and the scrap yard, i have the motor running all the time and just switch it on and off as i want it and it works very well the clutch still let you use the table by hand.

Ty Kevin

My method is crude in the extreme. An old wound field 12V wind screen wiper motor, with the shaft of the worm wheel extended to take a 10 tooth sprocket. A 20 tooth sprocket is fitted to the lead screw, next to the hand wheel, a bit of bike chain of suitable length is joined up, make it loose enough that it can be easily lifted off. A switch that gives on, off, on for left, off, right, and a power supply, mine is 18V, but a battery charger should do it, 20V+ would be OK, even better would be a truck wiper motor for 24V, a 36V power supply would be about right. Took me about 2 hours to make, including the sprockets, it could be a lot tidier, but it works. Ian S C

Dave,

All the info you need is in MEW No.110. That issue also has some good info on making toothed belt drives which might be useful.

Cheers

John

Right then, trip to the scrapyard it is. Some terrific ideas that I can easily build on/modify.

As a bit of trivia, I do know that one Mig welder manufacturer used to use Volvo windscreen wiper motors as the feed motor because of their reliability.

I will let you know how I get on but today is my day off - so I am off to the workshop to catch up with all the projects I have half finished/started. Pics to follow!

graham.

Not sure if it helps, but have a look at this? Designed for a Sieg SX3 which is what I have but could be adapted perhaps?

I have got as far as buying the electronics and motor but need to fabricate the mounting plate/coupler etc still

Hasn't cost me much so far

Regards

Chris

Hi Guys.

thanks very much for the info. Like Graham, it looks like the scrap yard idea wins. Unfortunately there is only 1 yard round here that will let you in. ( those dam health and safety rules   the ones that won't let you in tend to charge an arm & a leg for stuff because they've had to take it off.

thanks again all of you

Dave

An up/down window motors are very good as they are designed to work in both directions, have low speed with gear box, some wiper motor are not reversable unless you alter the brush postion which is not easy. Also a dog clutch is useful,so that its easy to revert to manual operation when required. Regarding speed control, in MEW Dec/Jan 1992 was a very good circuit diagram together with comprehensive construction details. Ted

Or you could add one of the commercial units shown on my smaller mill above. Axminster and others used to sell them