Hammerhead Magnetic Carriage for Delta printers

by AdrianW Sep 15, 2016
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Very interesting!

I've purchased Haydn Huntley's mag ball studs and arms (215mm). I'm now trying to plan how to upgrade my Think3DPrint3D Kossel Mini without loosing too much build area. This seems like a great choice for the carriage.

Now to try to pick an effector that won't lose too much space. Ideally I'd find one similar to the T3P3 version (which looks very close to the original) but just with the angled mounts for the ball studs (which might require a few more mm between sides to allow the balls space).

Actually, since I'm not using linear rails, and my carriages already stop very close to the endstops, maybe I should use your standard piece.

you may want to check this out


Mag Ball for open builds Mini V wheel plate
by AdrianW

Thanks for the guidance, and the pointer to the item above. I appreciate it.


If you are not using the liner rails then the Hammerhead is not a good choice. Most of the wheel based designs need balanced forces on the carriage. Otherwise, they tend to bend or twist. The linear rails are less susceptible to this sort of thing.

They work very well on my mini kossel. But I have liner rails.

Best of luck. I have an effector in the works but I don't think it's ready for public display.


You do realize that this carriage design is reducing your maximum build height by a fair margin?

HI CobaltGriffon,

Thanks for your question / statement.

In short, No. Let me explain.

The drilled and tapped ballberings are attached to the TOP of the carriage. The end stops for my delta printer are all at the top. So the balls end up the same distance from the end stops when the printer is homed. Thus, the effector starts at the maximum distance from the bed. This, on most delta printers, defines one dimension of the the build volume.

However, the slide on the liner rail is MUCH lower than on a normal Kossel when the printer is homed.

I have attached a few new pictures to help. I have been running with these since I uploaded the design.

I hope this helps.

Great Question!
The short answer is no. They are not balanced. Both those loads are very different.

Many people are concerned that too much “torsional” force will cause the liner slide to jamb or “wiggle”. If there is that much “slop” in the liner slide you have a bad slide in my opinion.

Now a bigger problem is flexing in the plastic part.

Magnetic ball joints are great for backlash. But a high jerk setting or high acceleration settings cause the ball joints to separate. So the forces will not exceed force required to separate the magnet from the steel ball. The part is designed to handle those forces. That is assuming that the print settings used to make the part are the specified values.

I hope that answers your question.

Will this design not generate more torsional forces on the linear carriage? Meaning that the applied force from the timing belt is not centered on the carriage mount. Is this somehow compensated by the weight of the arms and hot-end?
I am just asking.
Thank you.