Plastigauge for V-Wheel Tightness?

Hey all,
since 5 weeks I’m a proud owner of an X-Carve and pretty satisfied with my results so far. I’m sure there is still room for improvements though. Thanks to this great community for so many helpful posts. I still try to get more precise and want to doublecheck my belt tension, stepper current etc.

The other day I was wondering if someone has heard of Plastigauge or tried it to check the tightness of the v-wheels. It’s a piece of plastic string and used to check the clearance of crankshaft bearings.

I know there are no specs for the v-wheels, but at least you could compare the v-wheels with each other.

What are your thoughts about it?

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I used it a few years back a couple times, it may be worth considering. Do you think it would work with the plastic v-wheels, or is it firm enough that it could possibly damage them?

I have been trying to standardize things also, and put out a couple videos on belt tension and adjusting the pots. If you get this to work, I’d love to see a video added to the maintenance video forum topic!

Boy does that bring back memories. I used it in the 60s and 70s on Coast Guard engines during rebuild.
I’m also not sure you would get good info in this case.

I wonder if one could use a very good inch pound or inch ounce torque wrench to check the torque on each eccentric nut as you set the amount of tightness of the V wheels.

Ariel, WA

There’s no proper belt tension either, but as a group I think we figured that out. I can’t afford a torque wrench at the moment though, so I’ll have to leave it to you for now. :smile:

The thing about using a torque wrench or torque screw driver is to be able to set all V wheels with eccentric nuts to the same setting. Then you are not relying on how hard or easy it is to get the V wheel to slip on the maker slide.

As to setting belt tension. I will be using a guitar tuner to set the belts to the same frequency.

Ariel, WA

Wow, Deja Vu back to my apprentice days…

On my machine, I’ve simply adjusted my V Wheels until I could no longer ‘easily’ turn individual wheels by hand. A bit of force will turn them, but they’re sufficiently tight that it takes a fair bit of effort. I’ve then added a second ‘locknut’ to ensure the eccentric nut stays in place.

This type of ‘fit’ is more of of an interference fit, than one where there is some measurable gap (however small). It’s more a case of pre-loading the bearings and removing as much backlash as possible without overloading anything.

Using a torque wrench on the eccentric nut is not particularly accurate as like any nut, bolt, washer combination, there are a great many variables, so I’d doubt it’d be any more accurate than what I’ve described above. If there was some way to grip it, using a torque wrench to measure how much torque is required to turn the V Wheels when they’re up against the rail might work, but in practice, it’s not something that will be of much use.

Once the V Wheels are adjusted, the plastic gauge would certainly be useful for comparing each set of wheels to make sure they’re all roughly the same.