Trampling the axis rods?

I have a wobbly 8mm rod, the printer I'm building uses the Ultimaker motion system and it's one of the rotating axis rods.

Rotating axis rod causes the "cross rod" bracket to visibly rise and fall when the bracket is half way along the rotating axis rod.

I checked the rod before I fitted it by rolling it on a piece of glass and it seemed straight.

Either it's bent or one of the end bearing brackets is high or low. Are brackets printed in PETg rigid enough to flex the rod?

The brackets are 1piece construction comprising of both the bearings at 90° to each other. So I know that the rod to rod vertical distance is correct.

I have a spare but before I try it I need to read up how to setup and fault find the motion system.

If you would recommend a resource I can read I would appreciate it.

I'm beginning to think that the Ultimaker system is more complex than I had realised. A simpler system like the old Makerbot might have been an easier build.

I'll get there ...

I can post a video tomorrow if it's needed.

Thanks All.

Aamcle

On happy day!

I took the motion system off and rechecked (I'd done it when I got them) the rods by letting the roll gently down a glass mirror.

Of the 4 axis (rotating rods) only one rolled perfectly so I checked my spares, I bought some extra as they were coming from China, and I havev2 more good rods but I think they are too short ........

How are it too bad? When they sound like a train going over a set of points it can't be good!

maybe a pic of your setup would get more suggestions

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[mechabits.co.uk]

Check if these 8mm are stainless or hardened steel, with a file. If the file bites, it is SS or low carbon junk.
Most probably SS as chinese use them for their cheap kits.
These are too soft and unsuitable as guide rods with the ball bearing LM.
Besides most are bent and not even the correct diam may be to be sold as 8mm for the World and 5/16 inch for the US !

In that case you need to buy the proper hardened steel rods. Chinglish description rank from pure lies to grossly misleading, so check for the buyer comments.

Edited 1 time(s). Last edit at 11/06/2020 03:49AM by MKSA.

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"A comical prototype doesn't mean a dumb idea is possible" (Thunderf00t)

They seek him here, they seek him there
Those reprappers seek him everywhere
Is he in heaven or is he in hell?
That damned elusive Aamcle

I guess the Journey is better than the destination, 2 years on the forum and not one pic...the material from a cube can probably make 3 Cartesians....so i'll be back in 6 years to see your progress.

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[mechabits.co.uk]