Wider Tyre Wheels

A makerslide wheel cannot handle much side force, and if the washer does not meet the wheel tolerances there is side play too. This leads to flex and possibly chatter.
I wondered if it was possible to make a better wheel within the size limit of the makerslide wheel.
The Makerslide wheels are rated 2.7kg so I decided that that would be the testload. Using a bellcrank and gauge I could measure the side deflection of the wheel with a load either pulling or pushing the wheel, any play should show immediately. The test jig:

The wheels were tightened so that you could still barely make them turn by hand.
In a Makerslide wheel the side force is transferred to the bearing on a 1mm plastic ridge on the inside of the wheel. In the modified wheel the side force is transferred to the bearing on the 1mm steel flange of the bearing.

The results are very conclusive.
The Makerslide wheel shows a deflection of 0.05 mm.
The modified wheel shows a deflection of 0.03 mm.

Hardly any difference:

For this test I used a couple of Openbuilds wheels and reduced the thickness to 9mm. The spacers were made from 1mm sheet metal. I have not tried to preload the bearings.


His finding was for .02mm. .02mm = 0.00079" (inches) I’ll keep the stock wheels too. :wink:

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Doh! I thought you were referring to the difference between the two deflection measurements. You’re right though, the original wheels are good enough…at least for this hobbyist.

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This shows that the majority of the flex in the Z axis is caused by the makersilde profile being twisted and not the wheels.

Napoleon “visited” us in 1795 and learned us about driving on the right side of the road, gave eveyone a lastname (son of john became johnson), meters, grams and being equal. When he “left” in 1813 we figured out that these things were not that bad and we kept those habits.

So yes I work in mm not inches.

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I guess 1971, so you are a sliding ruler and punch card generation too?

My dad was. :wink:

Those were the days, boats were made of wood and men from steel.

Back to the topic, the wheels convinced me that for a better Z axis I can keep the wheels. With the double load capability I can stick to 4 wheels to making thing easier to assemble and adjust the proper tension.

The force in the test was applied straight into the wheel. On the machine there is a rotational torque from the z axis. Put the dial caliper on the machine and apply a rotational torque on the router. There are several things flexing and the wheels are one of them. Open builds wheels flex less and steel wheels even less. Does it matter, yes when your trying to cut a press fit bearing hole in Al.

Great thing about the x-carve, it’s open source. So you can swap out the wheels for rack and pinion or chains or lead screws if you want. Personally, I keep looking at the chain drive mods and hoping a kit comes out that doesn’t include a plastic or 3d printed cog.

Torsion of the Z makerslide, can be compensated with an extra slab of mdf to bring the lower Z wheels at the same height of the lower X wheels
Crushing the Z makerslide, maybe more wheels
Better wheels, possible

So for a better Z axis with less flex the construction needs to change, I wonder how good the SO3 setup is compared to the X-Carve