Time for a Mesa Card Upgrade.

I am running into a step rate issue with my current set up. I think I am running something like 32K which translates into only 70IPM, for my stepper system. I am running a desktop CNC router and would like somewhere closer to 200IPM. I am using a standard pin out from the parallel port. Will the 5i25 give me the performance upgrade I am looking for or do I also need a card to go with it? If that is the case what board would you recommend? I would like something that has 4 axis and also has some I/O.

Thanks,

Assuming all other components of your machine are capable of faster speed a 5i25 and 7i76 combination is popular.
store.mesanet.com/index.php?route=produc...=7i76&product_id=119
store.mesanet.com/index.php?route=produc...oduct&product_id=215

Rick G

Assuming all other components of your machine are capable of faster speed

That is the crucial point.

There is a finite limit to how fast a machine can move, factors include gearing, multi-stepping, table weights, motor power, driver capabilities, power supply etc

You need to be sure that spending £200 on cards will actually do anything.

If you have a low power, heavily geared, small router it might be a complete waste of time and money.

A 32K base-thread is pretty good.

If you even could increase speed to 200ipm, are your motors capable of cutting a given depth at that speed or will you have to reduce cutting depths, in which case you are moving faster but doing less, so no advantage.
Increasing pulses will not make you motors more powerful, in fact the opposite, the higher the speed the lower the torque.

Think hard on it.

regards

If you are using micro stepping you might try lowering that if only to see if the rest of your hardware is capable of moving faster.
As ArcEye pointed out stepper motor torque drops off rapidly after a certain rpm.

Rick G

can you give more details ?
type of stepper drives used & voltage and amperage of power supply is a good start .
and if using microstepping why ? , (using half step is a good base )
what type of machine is it ?

in a lot of cases increasing voltage will help , but this depends on the spec of the stepper driver .

I am running 425 oz/in steppers of a 36v power supply. I am running 2000 steps/rev, thats 10th micro stepping with a 5mm pitch lead screws, which at 70ipm puts me at 356rpm if I did my math right. I have stepper drivers from longs motors, I think its the same thing as: Wantai Motors DQ542MA. I built the machine entirely from scratch and made it pretty beefy, the sides are 3/4" aluminum and is built with aluminum extrusions and good quality linear rails and bearings. It's a very rigid machine. From reading the responses it sounds like I should upgrade my stepper drivers and maybe my power supply. I could also decrease my micro stepping, however I do like the resolution I get with 2000 steps/rev which is pretty close to .0001'.
'

I could also decrease my micro stepping, however I do like the resolution I get with 2000 steps/rev which is pretty close to .0001

Are you telling us you need 2.5 micron resolution from a router?

Just reduce your microstepping to 4x and see if you can more than double your speed without hitting problems - simple, no cost test.

From reading the responses it sounds like I should upgrade my stepper drivers and maybe my power supply. I could also decrease my micro stepping, however I do like the resolution I get with 2000 steps/rev which is pretty close to .0001'.
'

Maybe not yet.

The point is you need to find out what the limiting factors of your machine are. You stated you wanted to go faster and you could not generate steps fast enough to do so. In which case hardware step generation will allow you to do so.
But it would be nice to see if the rest of the machine can go faster. For the same step rate you have at 10 micro steps per revolution if you change to say 5 micro steps revolution for the test the machine could theoretically move twice as fast.
So if you reset your drivers to a lower step rate, change your configuration to reflect the new setting and see how fast your machine can now operate. If it test out O.K. and you want to keep using 10 micro steps the mesa setup will allow you to do that.

Here is a sample torque curve...
www.automationtechnologiesinc.com/wp-con...KL23H286-20-8BTC.pdf

Rick G