Z Motor Upgrade

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ob1
Posts: 11
Joined: Fri Jan 27, 2017 10:44 am

Z Motor Upgrade

Post by ob1 » Fri Jan 27, 2017 10:49 am

If you're contemplating upgrading your Z axis motor from the original silver frame to the new black frame then here is a procedure to help you out. Have a look at http://turtlesarehere.com/html/m2_upgrades.html.
Note that a RAMBo software revision will also be required.

t.

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willnewton
Posts: 473
Joined: Wed Apr 09, 2014 8:32 pm

Re: Z Motor Upgrade

Post by willnewton » Fri Jan 27, 2017 4:36 pm

I may have missed something here, so help me out.

You want swap motors to improve the steps per mm on the Z from 400 to a 1000-ish, yet the practical limit of filament printing (.10mm layer height) is 10 steps per mm. Even impractical .05mm layer heights only require 20 steps per mm.

So if I am figuring correctly, you would need to be printing at .001mm layer heights to take advantage of your new stepper.

In broad generalization, 90% of most printing on the M2 is likely to be done at around .20mm layer height, only needing 5 steps per mm.

So......does this change work in the same way a louder exhaust makes your car faster? ;)

I am not knocking your upgrade or desire to learn or the work you put into the informative web page (which is very nice), just seems like a lot of work for little gain.
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/about

ob1
Posts: 11
Joined: Fri Jan 27, 2017 10:44 am

Re: Z Motor Upgrade

Post by ob1 » Fri Jan 27, 2017 9:06 pm

@willnewton. A fair call on the resolution but my primary motivation is an M2 upgrade to Revision E. One immediate advantage of the new drive is that it appears to stop the bed fall of the original drive (but I'm interested to see if this is retained as the new Z drive beds in through use). I figure this comes from the reduced pitch of the new lead screw (about 6.3 mm compared with 7.8 mm) and the increased length of the associated bearing (1" c.f 1/2"). The procedure my also be useful for folk that choose to upgrade following a Z drive failure.

spmahoney78
Posts: 21
Joined: Thu Mar 24, 2016 1:01 am

Re: Z Motor Upgrade

Post by spmahoney78 » Sat Jan 28, 2017 2:14 am

the change was important enough for the manufacturer to do it. Please explain why the new machines should have the new motor but I should not update my older machine? MakerGear won't explain it to me, they just say that they don't offer an upgrade option.

ob1
Posts: 11
Joined: Fri Jan 27, 2017 10:44 am

Re: Z Motor Upgrade

Post by ob1 » Sat Jan 28, 2017 12:06 pm

Yes, MG have seen fit to upgrade the M2 Z motor and lead screw. The reason for this appears to be captured in Brad Hill’s post at https://groups.google.com/forum/#!topic ... qC0xmOzNMQ. It concerns load, precision, accuracy, noise and motor resonance.

While MG do not yet offer an upgrade kit you can order the parts. You will need a new Z motor with lead screw, a new Z stage, a new Z motor cable, and a new top bearing.

The Z stage is always under load (this is Sir Isaac Newton’s fault). My understanding is that the old (silver framed) Z motor was driven with 8 micro-steps in a 1.8 degree pole step. The old lead screw allowed the Z stage to drop under its own weight until balanced by an increase in Z motor current.

The new Z axis lead screw has a finer pitch, reduced diameter and increased bearing length. These appear to prevent Z stage free-fall. The new (black framed) motor allows 16 micro-steps in a 1.8 degree pole step. So the Z motor holding current should be less than the original motor and any gravity deflection should also be reduced. It would be reasonable to expect that the effects of drive noise on Z stage travel and resonance effects should also reduce.

If you are getting satisfactory prints with your current Z stage then there is no impetus to upgrade. However if you want to push the capabilities of the M2, upgrade your printer to the current revision, or if your old Z stage has died then this upgrade may be warranted.

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willnewton
Posts: 473
Joined: Wed Apr 09, 2014 8:32 pm

Re: Z Motor Upgrade

Post by willnewton » Sat Jan 28, 2017 12:15 pm

I have no idea why they changed. It could have been they simply ordered a new batch with different specs. It could be that this motor was $0.50 cheaper. It may have no importance at all other than that. The MG staff will have to weigh in.

As for not offering an upgrade, it may be that they have revised the firmware to work with the new motors and don't want to end up having to provide free tech support for a homegamer swapping parts. Rick has definitely made posts referring to the limits of support he can reasonably provide and stay in business.

I am not telling you what to do. I just presented you with information showing that the capablity of having more steps per mm doesn't necessarily make your printer more magical. If the post was about swapping out a V3b for a V4 nozzle I would have said, "DO IT NOW!" because that single change was a large leap in performance and capabilities.

You will have to decide if this upgrade is worth it or not. The OP has a great tutorial on it.

I have made many "non-performance enhancing" upgrades to my own M2. There are some revE upgrades, like the revised spider/z-stop upgrade, that I will probably never do, because I happen to be able to level my bed just fine. At the same time, what is a non-essential upgrade to me is a blessing to a new user and I would not choose the old system over the new.
I'm finally back to where I started two days ago!

A thread with some stuff in it I update every once in a while. viewtopic.php?f=8&t=9
See some of my stuff http://www.thingiverse.com/willnewton/about

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