Upgrading motors

Hey all,

I currently own a Felix 1.5 Rev E, and I'm looking to upgrade the electronics from a RAMPS board to a RUMBA board, and upgrade the motors in the process, but I'm having some serious dificulty in chosing the motors.

Firstly, this is the board I'm planning on getting: [www.reprapdiscount.com]

Secondly, the plan is to use the following motors:
X axis: NEMA 15
Y axis: NEMA 15
Z axis: NEMA 17 (Linear motion on with the threaded rod)
Extruder 1: NEMA 11
Extruder 2: NEMA 11

The extruder is going to be a direct-drive E3Dv5 based design, something like this [www.3ders.org]

Now, the plan is to get all the motors EXCEPT the Z-Axis NEMA 17 from Zapp automation. The problem is that it's a minefield as far as picking the right one. How do I know what to go for as far as things like voltage rating, current rating etc? All the motors are pretty much the same price, but I don't know how to figure out which ones I should be ordering? I know that I'll have to probably rewrite a load of the electronics code too, but that'll come later. I have to figure out the motors first!

Help please!!

Anyone able to shed some light?

Without knowledge of the Felix (new one to me) and what you require from the upgrade, it is hard to give any specific advice. Motors are obviously a tradeoff between size, cost and power. I'm not sure what you mean by "upgrade" in this context.

There is a lot of general information on the wiki [reprap.org]. Regarding voltage I would highlight the following

Quote

For this reason, stepper motors rated for 3-5 V and 1-1.5 A are generally recommended, as these motors will perform near their peak torque with a current-limiting stepper controller (such as a Pololu A4988).

although 3-7V is probably ok.

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That's a good start. Thanks for that! I'm anticipating that I'll have to do a bit of works on the arduino code too, but I've seen a few guides online that go through it. I'll stick with those guidelines and see what I can come up with.

I'm using the G3D drivers with a 2.5A Nema17. I have the same motors on my other printer too, but they use the Pololu stepsticks imitation version without a 2nd trimpot for the oscillation.

I notice a huge difference in how the motors behave, but on both printers I've never had any torque problems. The advantage for me was that the motors don't overheat because they can easily take the current. The limiting factor in this case would be the stepper drivers.

Just a little question, why would you want to upgrade your stepper motors? And keep in mind that when you use different Nema types, the size will be different, so this means that the spacing of the bolt-holes is also different

Quote
Ohmarinus
I'm using the G3D drivers with a 2.5A Nema17. I have the same motors on my other printer too, but they use the Pololu stepsticks imitation version without a 2nd trimpot for the oscillation.

I notice a huge difference in how the motors behave, but on both printers I've never had any torque problems. The advantage for me was that the motors don't overheat because they can easily take the current. The limiting factor in this case would be the stepper drivers.

Just a little question, why would you want to upgrade your stepper motors? And keep in mind that when you use different Nema types, the size will be different, so this means that the spacing of the bolt-holes is also different

Yeah I'm starting to get a good idea of the kind of things I'm looking for as far as motors and electronics go. The RUMBA board does seem to be a logical progression for me to go with from the RAMPS board. And I can stick to the ratings that bobc suggested.

As for the why-upgrade-the-motors question, it's part of a number of upgrades I'm doing. The motors I have are fine, albeit noisy and the Z axis is a mess because of a mediocre coupler and rail bearing. So when it comes to the new motors I'm looking at, there's a number of different reasons for the upgrades:
X axis: General improvement
Y axis: smaller + lighter but still with enough power. It's mounted on the gantry, and that's being re-designed for a new Z axis rail/linear motor, so a lighter motor is better.
Z axis: Linear motor to work with new Z linear rail bearing and redesigned gantry.
Extruder(s): Looking at upgrading/designing a new extruder, many of the upgrades done on the felix are to go to an E3D based bowden design. BUT, bowden ones still have issues with flexible fillament. The idea is to design a light, dual-direct drive extruder, hence the light motors. Thing is, and this is a really interesting one, I wouldn't imagine much torque is needed for an extruder, so I wonder would I get away with a NEMA 8, although sticking with a NEMA 11 is probably just a safer option.

Alright, if you want to solve the 'noise' issue, there are two things you can do. It involves either changing something in your stepper driver by soldering a resistor on a specific place (I don't know exactly how it works, but there are enough people here that can explain it to you better than me), or, get the G3D stepper drivers. The second trimpot functions as this resistor, and you can turn it up to where you like to solve the noise your stepper motors are making

With the old printer it was annoying that I could hear it while watching TV, with the new printer, I have to turn down the volume and look over my shoulder to see and hear if it's still running, and even with the TV-sound muted I can barely hear the printer in a quiet room.

So, there is a big chance the stepper drivers are making the stepper motors noisy.

Second, I still think Ramps is very good.

Third, I don't think a motor < NEMA17 will give you the torque you need for direct extrusion. Unless it is a geared stepper motor. But even with a NEMA17 motor direct drive is barely achievable. You would surely need to use 1.75mm filament.

I hope this is useful for you to know, and if someone disagrees, please step in!

Ah I see! That's definitely something I'll look into. Thanks for that!

As for the motors, I'm currently using 15s for direct drive because it is running 1.75 filament. See, I'm trying to make something like the new extruder from micron [www.3ders.org]
I just noticed that they use an 11 motor with a 1:13 gearbox. Actually, the spec for the motor is on that page. So what I'm now wondering is 1) could I just get a geared 11 with the same spec? And 2) how difficult would it be to configure a geared stepper?

Thanks again for the help by the way! I know some of this is very ambitious, but the help actually makes me think it's not unachievable to do these upgrades.

Decent start to my Monday morning, fresh delivery of 1kg Grey ABS and 1kg Grey PLA. Gonna use those for the plastic parts! Gotta love those emails that say "Your package has been delivered!"

Ok, so I think I'm finally making headway on things. I've picked out a rail for part of the Z axis, a 300mm hiwin rail, gonna order that later. /tangent

I think I've managed to figure out which motors to order, but I want to just double check, so if someone could have a little glance, I'd really appreciate it!!

X+Y axes: [www.kysanelectronics.com] (recommended on RepRap wiki)
Z axis: [www.kysanelectronics.com]
Extruders: [www.kysanelectronics.com]
(For the extruders, the plan is to make something like the Micron extruder, so the motor seems to match their spec. I'll be printing with 1.75mm, through a 0.4 or 0.35 nozzle, and an E3D v5 hot end. Micron extruder here: [www.3ders.org] )

As far as the electronics, the RUMBA board seems to fit the bill for things like the number of fans etc, but also taking into account the ease of use. I'm just hoping it's fairly straightforward to write the arduino code for it!!

Anyway, motors seem ok??

Just make sure the geared stepper has METAL gears! If it has plastic gears inside, those wear quicker and when the motor gets stopped for some reason, by a blockage in for example the extruder, the plastic gears may damage.

I cannot confirm the motors for you since I am using Wantai stepper motors, so someone else should confirm I have no experience with Kysan, however I've seen them around on the machine a lot.

Ok, so I decided against paying $331 for shipping (what the!?!?) so I'm back hunting for a geared nema 11! Out of interest though, considering it's extruding 1.75mm filament, would I DEFINITELY need to gear a high torque nema 11?