My turn for help with Pulse multiplier for test rig.

[cropwell]

But in mean time please keep giving the suggestions but just remember only needs to be simple doesn't need any thing fancy I'm not after accuracy or any kind of CNC pendant.!!

How about a USB games controller like this. Mine cost me nowt, uses keygrabber and the biggest hassle was putting the labels on the keys.

[JAZZCNC]

How about a USB games controller like this. Mine cost me nowt, uses keygrabber and the biggest hassle was putting the labels on the keys.

Nope.!! . . . . Remember NO PC involved.

[Neale]

...and the only reason that the Arduino-based approach fails to meet the cost criterion is because people think of buying a complete Arduino board. But an Atmega chip only costs a couple of quid (for one of the smaller dual-inline versions) and if someone could develop the code and burn the odd chip or two, it would barely cost more than a 555 with a couple of switches and a pot. In fact, it's the reason that the simpler microprocessors were developed in the first place, to avoid boards full of logic chips. I took this approach recently with a soldering iron temperature controller, but I have too many projects on the go already to put my hand up for this one, I'm afraid. So, watching with interest to see what turns up!

Ex-G8BYK, now G4FBN, and wondering how it would have been done in thermionic valve days...

[stirling]

The more I think about this - the more crazy it gets. A MANUAL pulse generator is exactly that - MANUAL. It allows you to step ONE pulse or MANY pulses under precise MANUAL control. That's it's whole purpose in life.

Earlier, with an electric drill attached. That makes it no longer MANUAL. The MPG became a means to an end. When you pulled the drill trigger, you might just as well have turned a pot.

The MPG is just becoming a distraction. Everything that everyone has suggested (even Irving with the ONE pulse per rev) is battling against the MPG's natural behavior. Whatever ANYONE comes up with it will no longer behave like an MPG - so why have it in there at all?

I reckon your back to the 555.

Sorry - short and to the point - I'm drinking here...

[JohnHaine]

Isn't it more obvious to use not electronics but a mechanical step-up?

[irving2008]

Tbh my approach just generates n pulses for each wheel pulse at a rate that's fast enough to finish before the next wheel pulse. To vary the multiplier pulse rate to adapt for the wheel pulse rate is much more complex and I'd probably start going the software route on that (but not beaten yet). I'm assuming Dean is just testing basic motion and maybe home/limit switches. I haven't provided any acceleration control - it's only 3 chips after all (optional 4th if you want an LED to warn of overrun, ie wheel pulses too fast for multiplier), plus 2 options for multiplier control, a dip switch giving 1 - 256 or a 4 way rotary giving 1, 10, 20 & 50

[Jonathan]

Tbh my approach just generates n pulses for each wheel pulse at a rate that's fast enough to finish before the next wheel pulse.

As touched upon earlier, the 'jitter' this adds to the pulse stream will reduce the maximum feedrate somewhat as the motors wont run as smoothly. How much is hard to say, but it could be a problem...

OK, here's version 0.1 for discussion....

Direction required?

[Web Goblin]

This might not be what Jazz needs for his project but it might be useful to someone else. https://neil.fraser.name/hardware/stepper/ttl.html

[EddyCurrent]

Fit a hand crank to the rear stub shaft of the stepper motor.

[Robin Hewitt]

Fit a hand crank to the rear stub shaft of the stepper motor.

That works on so many levels, a complete solution, I am truly in awe