cheap bipolar driver kit

[balsaman]

I found this link posted on another forum. Has anyone tried this driver?

http://www.electronickits.com/kit/co...tor/ck1406.htm

5-50 volts, $20.00 per axis.

E

[fyffe555]

Hi,

Yes I tried this one, and a very similar version #3-303 for Unipolar by Oatley/Mondotronics. Just used the schematics off the web because I had the parts.

Here's what I found;

Both work ok and ran without problem on turbocnc from a regular pc, using Pacsci 23 motors.

I like the added 5v regulator on the ck1406. Had noise problems on the 3-303 which didn't happen on the ck1406. Only difference in the setup was the board itself.

The ck1406 also worked on a laptop that doesn't source enough ma to drive my commercial drivers (ims483). This is because the first component in is the opto whichcan source enough to drive the rest. The 3-303 wouldn't run on the laptp because the opto is after the logic. Both run on 3' cabling.

Both where fairly slow - couldn't drive more than about 6000 steps/sec.

Even with hexfets the output fets got very hot running at 38vdc (24v rectified) for more than a few minutes on both kits. Need a fan and heatsinks for longer running. Note the kits says 5-30v motor voltage - the output stages irfz44 is 60v 50a rated, the mtp2955 is 60v 12a. I think because theres no curent reduction when the powers on but no stepping occuring.

Motors also ran noticably hotter than they do on a commercial driver.

Neither kit allow fractional/microstepping.

I built them to try out pcb making and drilling methods. For the effort involved and cost of the materials the board alone is almost worth the 19.95.

hth

Andrew

[balsaman]

6000 steps per second is 1800 rpm on a 200 step motor. Quick enough for most aplications considering its a full step only drive.

It's not a chopper is it? You still needed current limit resistors?

E

[fyffe555]

'6000 steps per second is 1800 rpm on a 200 step motor. Quick enough for most aplications considering its a full step only drive.'

True - I guess its relative. I run my X & Y at 1/8th step or 16,000 steps per inch on 1.8 steppers and 1/2-10, 600rpm is 60"/min. It sounds like a turbine, smooth and relatively quiet. Single stepping sounded like a staplegun each step and vibrated the machine and the motors run hotter.

'It's not a chopper is it? You still needed current limit resistors?'

No it's definitely not chopper - resistors are needed as per normal non current regulating drives...

They're a well thought out and effective drive I think, as long as you don't need microstepping. From the number of people selling kits on basically the same format they're pretty well proven too, and if anything does blow its cheap and easy to replace. I'm going to use one or the other on a foam cutter I think, putting all four drives on one board and use a very fine pitch screw.

[davesaudio]

many of these kits originate here
http://kitsrus.com/
kits r us

[ballendo]

Balsa,

You probably already know this, but you can't assume that 6000 microsteps will translate into 6000 full steps...

More like 4000, if that. Because once yo come back to full steps, you also come back to resonance problems and issues which may severely limit the top end you can get. Like the old Yankee joke:

"Oh!, Ya wanna go There? Ya can't GET there from here!"

Ballendo

Originally posted by balsaman
6000 steps per second is 1800 rpm on a 200 step motor. Quick enough for most aplications considering its a full step only drive.

It's not a chopper is it? You still needed current limit resistors?

E

[Stevie]

well I've ordered 1 to play with; I'll try anything once

I wouldn't mind just using it as a manual jog if the thing has not got the power to drive my big steppers; I do have some 17 sized

[Stevie]

It arrived today; nice looking board; all the parts seem to be there; I'll start soldering it together later

All soldered together; went nice; in fact my 8 yr old enjoyed finding the right resisters (she liked the colors)
I even got 1 extra resister; Rachel enjoyed trying to bend it right to fit the holes in the board; but she did not want to try soldering

Anyway; the drive is rated to 6amps; I'm wondering if I need to microstep with 0.05" pitch; 1 step with 1.8dgr would be only 0.00025"; for my lathe project this might be the ticket; the cross slide is 1.5mm pitch; close enough to the 0.05" of the saddle pitch
I'm a bit lost on the IPM; I think it's about 30 RPSec (6000 div 200 steps = 30) or 1800rpm thats 90"PM; can that be right

[woodcam]

A heads up on the same bipolar driver, the Allegro a3977, that is used by Xylotec and others - mircrostepping is built in to the chip, pretty amazing, will drive up to 2.5 amps and costs $5.90 from Newark - bare single axis board for $10.00 at :

http://www.thsengineering.com/produc.../thstep25.html

[Stevie]

this board hasn't got that chip; but good find nice cheap board using the Allegro a3977

[davesaudio]

its too bad that the chip doesn't have pins to give access to the
h bridge input. it would be nice to beef up with an external fets

[kfong]

How about this design, 3amps and up to 55volt. The nice thing is it is a microstepping chopper driver board. Software is open source and the design works great. Very smooth at 8 microsteps.

http://www.embeddedtronics.com/microstep.html

Kin Fong
http://www.embeddedtronics.com