UMO upgrades, heated bed, Z axis, belts

[JohnInOttawa 62]

Good afternoon everyone. I will start with apologies for likely asking about things on other threads. My (newbie) search didn't get me to a solution, so my hope here is to try and collect the wisdom on one thread.

I have one (and maybe two in a short while) Ultimaker Originals, both used. I believe the hotend has been upgraded on the one I have, unsure about the second. Neither have the heated bed upgrade, although one has had the Z leadscrew and nut changed, still using a coupling. The other will almost certainly have the original lead screw.

I would like to bring both printers to the same standard so I can run them interchangeably. Most jobs these days run over 24 hours and there is a backlog, so having the ability to have one down for setup, cleaning or maintenance without being pressured to get going would be useful.

That's the background. What I think would make sense for me are the following (and here is where you come in to tell me if I am off base)

1) Heated bed upgrade for both. Some issues:

I know the UMO heated bed kit is virtually extinct. There are a number of UM2 options. Will the UM2 aluminum plate fit the UMO? It looks identical to me, except for a small tab on the back side which looks benign to me.

I can't locate the integrated Z screw/stepper in the places I am looking. Either the pitch is wrong or the motor is. Any suggestions here? If I just change the lead screw and nut to the right pitch and stay with the coupler, do I lose the benefits of the upgrade?

Flanged linear bearings - Any suggestions on better or worse sources?

Heat plate - ditto

2) Belts - I am thinking GT2 is a better setup and was thinking of sourcing from Robotdigg. It looks like a straightforward mod, but would appreciate knowing the pitfalls, tips and tricks in advance, will order accordingly.

3) Power supply and motherboard. I am almost certainly on the original UM motherboard. I think this will limit my options for which UMO+ or UM2 options I can apply. Specifically stepper motor wise, do I need to choose different steppers for the UMO vs UMO+ or UM2?

Is there a critical mod that I have overlooked but the veterans here would recommend?

Thanks again for your help, once again, apologies for overlapping on other similar posts.

Cheers

John

[amedee 338]

A couple of quick answers...

1) Yes, it is a pity, no HBK anymore. There is no difference between the UM2 and the UMO-HBK/UMO+ heated bed. If you try to retrofit an UM2 HB, you need to take care of the following:

- the lead screw is different, so you need to change the lead screw or buy the combo stepper/lead screw from UM as well.

- the temp sensor is a PT100, so you need an E3D amplifier

- it should operate in 24v (see (3))

- the wooden 'cover' is different, but you can print one (I think @neotko has printed covers)

2) GT2 from RobotDigg is a no brainer, there is a post on this forum with all the details on what you need to order

3) PSU: UMO is designed to run at 19v, but you can use a 24v PSU but you need to replace the original 12v linear converter on the board by a switching step-down regulator (search for 24v UMO on this forum). Going to 24v will make things easier in particular for the bed -- be careful with the hot-end fan if you are still using the original one, as it is a 12v fan over-powered in 19v and I don't think it will like 24v

Also check the version of the electronics (they range from 1.5.3 to 1.5.7), they all work equally good, but there are some small differences like the way the Arduino is powered, the electronics fan or the pinout of some connectors...

[JohnInOttawa 62]

Thank you!

I will go for easy stuff first, GT2. It looks like that also involves replacing the blocks, I presume bushings as well.

Does the new lead screw improve resolution noticeably?

Excellent info on the electronics. I will look to see what standard the board is at.

Cheers!

John

[amedee 338]

For the GT2 mod, I posted a "BOM" here.

I personally recommend the "Twister blocks", but there are other options -- you need to keep the brass bushings.

While you are at it, do this mod as well.

Re. the lead screw, I always had very good result with my old UMO, not sure the new lead screw made a difference. The build plate is more stable and obviously the big win is the heated bed. The only thing you could argue is that the UMO lead screw is not metric, so some rounding needs to happen wrt the layer height...

[mariuszem 4]

I do use https://www.youmagine.com/designs/lars-ultralight-ultimaker-xy-blocks as new blocks for GT2 belts and I liked them more.

When you use UM2 HB, you'll need E3D or MKS PT100 aplifier. Lead screw will need a change also - use step driver with same lead as original. Than you'll use same steps as with HBK upgrade (200).

The lasercut for HB case is hosted on Git. Use only the side that is used to trigger endstop.

You will need 24V PSU and new regulator, as amedee pointed (search for TRACO POWER TSR 1-24120).