New Max V2 build with Magnetic ball mod.

[Boundless]

Hey guys,

I am new to 3d printing and my V2 kit should be here soon. I have done alot of reading and research to mod the arms and effector with Xnaron's magnetic ball mod. A few of you have already made this mod and are seeing "night and day" differences in quality prints. The pictures of prints I'm seeing are amazing and I would be thrilled to get similar results.

This is a mod I already plan on doing and yesterday purchased the 3/8" magnets and 3/8" chrome steel balls. Naturally, when my kit arrives, i'll still have to assemble it with the stock components to be able to print the parts I need.

I am considering going to a hobby store and buying 3/8" wooden dowel rods or carbon fiber rods to cut to the 240mm length I need for the arms.

Has anyone considered printing and selling the effector, rod end caps, and cheapskate adapters, credit to and permission from Xnaron of course? Any tips for a new builder? Would it be easier to buy the printed parts and assembling than assembling, printing, disassembling, modding?

Chime in if you have plans to do the same mod or already have.

[Polygonhell]

The original (Kickstarter) Max's had an issue where the universal joints required sanding of the arms for the right fit, many people had difficulty doing this well and there was a problem associated often referred to as "the delta arm blues". After Werner Berry showed the Berrybot, magnetic arm solutions became popular.
For the most part this is a resolved issue now, and you shouldn't need to replace the stock arms.

If you replace the arms you will introduce scale and radius issues, and you will have to dick around with the firmware to resolve them, and there is no guarantee you will get better prints.

Personally I am using the original kickstarter arms and my print quality is comparable to any I've seen posted here.
I think you are much better off getting the printer dialed in before you start randomly replacing parts, there are too many variables in getting good prints to start introducing a whole bunch of new unknowns before you've tuned everything else.

[Tinyhead]

^ Second this.

I have a V1 that has the same updated arms as the V2 and I went to the magnetic arms. There was little to no appreciable difference in print quality between the two. The stock arms are very good. Making the magnetic arms involves a fair bit of pissing around and you might get dropped balls, or the hot end nozzle may hit a lifted part of a print or something and knock the effector right off the arms. It's happened to me a few times.

If I were to do it again, I would probably leave the stock arms, but make sure the u-joints are lubricated properly and check them every once in a while to make sure they are still loose. After a month or so I did the magnetic mod and found my u-joints were starting to seize - even with lubrication. This may have been a materials/metals thing that's been resolved since, but that would be my only concern.

[notarat]

This is a mod I was seriously considering doing when mine arrives but, after reading that the stock arms should be sufficient, I think I will hold off.

That gives me more time to resolve the alignment issues when Dualstruding on my Creator X, anyway

[Boundless]

Thanks guys,

I think you've adequately scared me away from doing the ball mod.

Since I have no experience updating firmware settings, I can only imagine a nightmare trying to dial the arms into the proper settings. Sounds like what I need right now is experience with the build and prints before I dive into mods like these.

Is lubricating the u-joints suggested in the manual?

Thanks again for the help. My line of thought was, since this is the initial build, yet to be calibrated, that doing the magnetic ball mod now would be easier rather than later. Didn't know the new arms were producing as good of prints.

Guess the magnets will end up on the fridge.

[geneb]

The current production axles have a special coating so lubrication isn't required.

g.

[Tinyhead]

I can only imagine a nightmare trying to dial the arms into the proper settings.

To be fair, if you followed all the instructions to a tee (I spent an unhealthy amount of time on my arms to make sure they were perfectly equal in length), then everything should turn out fine. After making the arms exactly as specified, it was then just a matter of calibration and a few setting changes in the firmware and the mag arms worked perfect.

[bdjohns1]

I've got one of the last v1 units before v2 came out (late-January), but I got mine with the old axles. Even after getting a bad axle replaced (had a burr) and cleaning up the holes on the aluminum parts, I still wasn't satisfied with the occasional "grab", and balancing freedom to rotate with the need to machine the effector precisely to eliminate slop in the joints. I'm not slamming the stock u-joint design, but I wonder - if it were really the best way to go, wouldn't we see more deltas using it instead of ball-joint rod ends or magnetic options? I don't care what you coat the axles with - metal on metal is a delicate thing to do right in motion systems.

As a learning exercise, I ended up designing my own effector inspired by one of flateric's designs, which reduces the z-loss associated with having an e3d mounted under the effector and uses the Traxxas ball studs, so no JB-Weld needed. One adjustment to the arm length, and a few iterations through the calibration sequence, and I was set. Did a print to make a replacement part for work, hit all my dimensions within 0.02mm.

As long as you make your arms all exactly the same length (easy with a jig), you only need to change 1 additional parameter - the diagonal arm length, and you should only need to change it once.. You technically don't need to worry about the end effector offset and the carriage offset anymore since Repetier is using the HORIZONTAL_RADIUS term to calibrate.

It's not a breakthrough improvement, but I think it was worth the exercise.

[Boundless]

Thanks guys for the replies.

[JohnStack]

It's not a breakthrough improvement, but I think it was worth the exercise.

That's a maker response if I've ever seen one. Huzzah!