Comparing motion controllers...

**JW1977** · 10-02-2016

Hi!
I am finally getting somewhere with my CNC Project and right now i am comparing the Csmio IP-M with the Ethernet smoothstepper from Warp9. Got some questions that i was hoping someone could help me with...

The CSMIO IP-M is interesting although it lacks functions that the smoothstepper has got. On the other hand, maybe i dont need em?

1 - I know what homing is but what does homing on "index" mean?
2 - The IP-M does not have backlash compensation. Is this a big "-" compared to the Ethernet smoothstepper or can this function somehow be implemented from Mach 3?
3 - Same goes for the ability to Control spindle speed. Can this also be done from Mach 3 in some way?

Thanks JW

**JAZZCNC** · 10-02-2016

If you are using steppers and don't need slaved axis or Backlash compensation then the IP-M is better option. Here's why.

The Cslabs controllers use 24V I/O which is very noise immune but more importantly they remove BOB from the equation which is weak area on any machine. This should not be under estimated because BOB's are big cause of trouble so any chance to remove is worth paying extra for.

Then you have built in spindle speed controller. Also another important area often over looked is the Software and support. Cslabs make excellent reliable software and support is great. This isn't the case with Warp9.
Quality of the unit has whole is excellent very neat and to industrial standard. The ESS by comparison feels weak.

Now to answer the questions.
#1 Homing on Index means if using servos with encoders you can use the Index pulse of the encoder to home more accurately than switches. It also allows much faster homing because can rapid at full speed towards the home position at which point you trigger a switch. This then slows the machine to homing speed then homes to the encoder Index pulse.

#2 Backlash is something to be avoided and best done by removing mechanicly not thru software. At best BL comp is fudge and not very affective. To me it has no value and wouldn't use it if did have it. I'd remove the BL mechanicly by others means or new screws etc.

#3 Spindle speed control is combination of hardware and Mach3. The IP-M provides Spindle speed control so it's no problem. The ESS does not and will need spindle speed controller or BOB with one built into it.

I've used just about most Controllers and NONE come close to Cslabs in quality and performance. If using the ESS then I'd only use one with high quality BOB like those from PMDX and if needing Spindle speed you'd also need there board for this. The combination of all 3 costs far more than the IP-M.

**JW1977** · 10-02-2016

Hi!
Im hearing you and im ready to go for the IP-M. Unfortunately my router design requires a slaved axis. I've read that the IP-M does support a slaved axis...? Do you know anything about this?

Many thanks for the support. You seem to be a really big asset to this forum...

**JAZZCNC** · 10-02-2016

Yes the IP-M does support slaved axis and does it very well but it doesn't home to individual home switches. This means you can't square the gantry using a switch for each screw.
This is important because when steppers turn on they often move to the nearest full step and if one motor jumps opposite way to other then over time it racks the gantry. So homing to separate switches allows you to square gantry back up.

I use lots of the IP-M and have been pleading with Cslabs to provide homing to separate switches but they are not too keen. I think because they don't want to hurt sales of the IP-S which I feel is wrong way to look at it. So I encourage you and others to email them and complain. Let them know that you would be prepared to buy if it had this feature and would never buy the IP-S for stepper system because of the higher price. Maybe if enough do this they'll re-think.? They did on making it Slave so they may again if enough people ask .!

**JW1977** · 10-02-2016

Ok, im gonna do that...
To bad, the IP-M is just right for all other reasons... Thinking about a way to do the homing without "twisting" the gantry.
Would it be possible to simply switch of the slaved motor each time you would want to home? To let one motor home that axis? Would that solve the problem?

**JAZZCNC** · 10-02-2016

Originally Posted by JW1977

Ok, im gonna do that...
To bad, the IP-M is just right for all other reasons... Thinking about a way to do the homing without "twisting" the gantry.
Would it be possible to simply switch of the slaved motor each time you would want to home? To let one motor home that axis? Would that solve the problem?

The IP-M will home the slaved axis but only using one switch. What needs to happen is for both motors to de-couple from being slaved together so while homing are independant of each other again and look for a switch of there own. Provided the switches are aligned this ensures each side is level and gantry is square again. Just having one switch whether that be moving one or two motors still won't straighten the gantry if twisted.

There is another crude but very affective way to ensure gantry is square and that is to bump up to hard stops which you know set the gantry square.

**Boyan Silyavski** · 11-02-2016

Pokeys57CNC can do all that,and generally i consider it much better option price wise or having in mind all possible options. If only CSLABS were not so dumb to make that slaving happen, which sure is a minor thing if they wanted to.

**JW1977** · 11-02-2016

1 – Can’t stop thinking if it would be possible to install a second switch anyway? Or is that what you just said?
Connected so that the signal that keeps the gantry moving continues until both switches have broken the circuit.
It’s not the proper way to think but I’m new to this and I guess if it would be that simple, it would have been done right?

2 – To install 2 reference “pieces” from where the gantry position on each side can be measured.
So once in a while after homing the gantry I can twist one of the screws manually to set the gantry square and then turn it on again.
Would that work?

3 – I could let both ballscrews be driven from the same motor but I guess that would require a belt and with that I would loose some of the precision.

4 – What is the downside of squaring it the crude way besides that it feels… Crude?

5 – Would it help a bit if I choose 400 step motors instead of 200?

**JW1977** · 11-02-2016

Is there any obvious flaws with the Pokeys57 compared to the IP-M?
Does it have onboard BOB?

**Clive S** · 11-02-2016

3 – I could let both ballscrews be driven from the same motor but I guess that would require a belt and with that I would loose some of the precision.

This is one of the standard ways of doing this and has been proved to work well. If you look through the forum there are many cases where it has been done this way.

Installing a second switch as your point (1) will not work. Point (2) Will work as Jazzcnc has already said (but it is not an elegant way of doing it). Not sure what you mean in point (5) it has nothing to do with the homing sequence