My turn for help with Pulse multiplier for test rig.

[m_c]

It's quite amazing what can be done with logic chips, however I'm like you Ian, I'd be using software and I'm eager to see what Irving comes up with.
Most of the early Gecko drives relied alot of pretty basic Logic chips, yet Marriss managed to do some pretty cool things with them.

Assuming Dean doesn't require to move the exact number of steps/pulses, then you wouldn't have to be that accurate about timing, and could miss some pulses.
For example, as soon as a pulse is input, output x pulses at a slow rate, then if another input arrives before the x pulses are generated, reset the counter to x and increase the output frequency and so on. That way you're never really behind the curve in terms of number of output pulses, and you don't have to handle buffering/predicting what's going to happen. Off course slowing down is pretty easy, however you may want to implement some kind of deceleration so you're not slamming to a stop as soon as you stop spinning the MPG from high speed.

And from there, you could also add a logarithmic style input, in that the quicker you spin the MPG, the higher the step multiplier is i.e. slow turn could be single step, gradually increasing to 50x at high speed. That way you can still maintain accurate slow speed, yet still move at high speed.

I could probably throw some code together, however I don't have any MPG to try it, and I've also currently not got any spare Arduinos kicking around! (I keep meaning to order some, as I've got a couple more prototypes to build, but that's currently on the roundtuit list!)

[Jonathan]

The standard circuit to multiply a frequency is a phased locked loop and there are ICs that implement it. If I recall correctly they don't handle varying frequency well.

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.

Not everyone - I suggested the pot. back in post #13... However Jazz said he 'would like to keep the detent control of MPG', i.e. be able to move a distance specified by turning the dial, not just set it at a speed and go. Either are easy to do with a microcontroller. The differential signalling very slightly complicates matters. I just suggested Arduino as although I dislike them, it's undeniably easy, but in post #14 Jazz seems to call that a 'massive electronics project'...

In software it is trivial - just stay one pulse behind, measure time (t) between pulses and output pulses at f=n/t where n is 10,20,50. If another pulse not received, output n pulses at your favorite frequency to catch up. But as Irving pointed out 'Dean wanted a learning experience too'.

To be honest I'm little surprised( slightly dissapointed) there are not more takers or more informed/detailed suggestions because I know there are plenty on here who do know how or could easily come up with something.!

It's more entertaining to watch and see what other people come up with. Plus I'm busy at the moment with another massive electronics project , so you'll hear from me if this isn't over in a month or two.

[stirling]

It's more entertaining to watch and see what other people come up with. Plus I'm busy at the moment with another massive electronics project , so you'll hear from me if this isn't over in a month or two.

ROTFLMAO - Effing unbelievable - That has to be one of the most effing arrogant statements I've seen you come up with to date. It's a doozy.

Hopefully the "entertainment" you get from watching the rest of us neanderthal cretins struggling with the concept of which way is up for one or two months meets with your approval.



Ah thanks Matey - you kill me.

[Robin Hewitt]

Hopefully the "entertainment" you get from watching the rest of us neanderthal cretins struggling with the concept of which way is up for one or two months meets with your approval.

I agree with Jonathan. Patently you don't understand what it is to be a geek.

From a geek perspective this is a request for a magic box of tricks that performs some nebulous function with a motor by reading Jazz's mind when he plugs it in.

If you think you can make it then you are either an extreme geek or a Neanderthal cretin. There is no middle ground

[JAZZCNC]

It's more entertaining to watch and see what other people come up with. Plus I'm busy at the moment with another massive electronics project , so you'll hear from me if this isn't over in a month or two.

Jonathan I'm even surprised you botherd to comment so I thank you for that.!! . . . . . As for your input then I expected no less from you.!!

Sorry to the rest for not replying sooner or keeping track of this but I've been busy all weekend wrestling unfriendly CNC machines.!!

Ok well let me explain again that ALL i want to do is have the axis move, doesn't matter if it misses steps or stops fast etc just move faster than 1 pulse at a time so I can get from one end of machine to other with cranking the handle 1000's a time.
All I wanting is like Irving says to move the axis while working on machines and for setting up limts switches etc. This is why I would like to have the single pulse detent for when close to limits etc. Before that it won't matter if it gets infront or behind with pulses etc and overruns or misses steps etc as I'm not after any accuracy and when I'm getting close to where want to be I'll drop to single pulse. Sure when used to it I'll know how it's going to react to my turning the handle at differant speeds.?

To those that have suggested mechanical options then YES I know this and I can even push bloody the axis if I wanted but that's not what I want so please don't go there anymore it will only take the thread off at tangents.!

Similar with the arduino and software based options, yes I know they are best or easier option and yes I've done some VB and C++ coding so could after cleaning the rust off gone this route and made it happen.!! . . . But again didn't want to. Just want it rough arse KISS approach and to learn from.

555 timer hasn't been ruled out but I would have to have the single step option like the detent of the MPG.

I'm flat out busy at minute but when I have more time I'll look closer at it and ask some folks I know that have done similair things.

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.!!

CHEERS:

[irving2008]

Added option to replace DIP switch with rotary for presetting step multiplier rate.

[FatFreddie]

555 timer hasn't been ruled out but I would have to have the single step option like the detent of the MPG.

How about a hybrid system, keep the MPG for fine control but have a button that also injects pulses from a (variable frequency) 555 timer type circuit? Direction is set by the wheel and that is used for fine adjustments but for rapid traverse, the button is used.

[Clive S]

How about a hybrid system, keep the MPG for fine control but have a button that also injects pulses from a (variable frequency) 555 timer type circuit? Direction is set by the wheel and that is used for fine adjustments but for rapid traverse, the button is used.

Bingo. ..Clive

[JAZZCNC]

How about a hybrid system, keep the MPG for fine control but have a button that also injects pulses from a (variable frequency) 555 timer type circuit? Direction is set by the wheel and that is used for fine adjustments but for rapid traverse, the button is used.

Yes this is an option and will be my backup if nothing full fulls my perfect needs.

Irving I'm following your design and with some googling I've found it uses a Hex Schmitt trigger, Flip flop and down counter so I'm learning already . . . . . . Now I just need to get my head around what they are and how they play together.

While googling the codes have been showing up with letters on the ends like "BE" or "BCM" what do they indicate.?

Should I start to play with this now and get these bits to play with or will there be more versions so hold off.?

[irving2008]

How about a hybrid system, keep the MPG for fine control but have a button that also injects pulses from a (variable frequency) 555 timer type circuit? Direction is set by the wheel and that is used for fine adjustments but for rapid traverse, the button is used.

Yes I'd considered this approach but rejected it as too easy lol, also doesn't truly meet Dean's original criteria.:)