|350 forum posts|
Fitting a DC variable speed motor to a Unimat 3.
Mounting independently of the lathe direct to the baseboard.
Should I bolt direct or sit it on rubber bobbins please ?
|martin perman||16/04/2019 10:30:46|
1519 forum posts
I would suggest rubber feet to stop vibrations appearing as marks on the job.
|Philip Rowe||16/04/2019 11:52:37|
|164 forum posts|
Many years ago I made my own countershaft assembly to drive my ML2, the belt tension between motor and countershaft and lathe spindle was was arranged by the motor being mounted on a hinged plate and the weight of the motor provided the belt tension. This whole arrangement including the lathe was mounted on blockboard which I think was around 35mm thick and the blockboard was in turn mounted on brick pillars. This worked well apart from the blockboard used to 'drum' to such an extent that it was very annoying. To offset this I inserted rubber mounts between the motor feet and the hinged plate, I tried different types of rubbery materials both soft and hard and I was quite suprised to find the most effective was a hard rubber that I made by cutting slices from a rubber door stop.
|Clive Foster||16/04/2019 12:35:28|
|1639 forum posts|
Thick wall "rubber" hose makes a pretty good vibration absorbing bobbin when forced into a reasonably thick substrate. Make the hole a touch undersize so the rubber is a tight fit. Cut the rubber overlong so it squidges out to make a flexible rim when things are tightened down. Through bolt needs to be a tight fit with large stout washers between it and the rubber so things squidge nicely. Best to use nylock or similar locking nuts so the squidge can be adjusted to tune things for best performance.
Generally I reckon 1/4" overlength each side works well enough with 3/4" to 1" thick substrates using my stash of thick wall car heater hose.
Similar technique without the squidge works well for stiff, shake free, pivots and hinges on things that only move occasionally.
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