Hello Everyone,
I've wasted nearly $300 on two different types of linear rail for the floating head part of my Z-axis (torch height control).
First linear bearing was IGUS which is a hard anodized aluminium rail and the bearing block has plastic sliding bearings which are adjustable. Problem is when you adjust the bearings enough to take up any play they are way too tight.
So cut my losses and ordered the typical steel rail and rectangular block. No play in this one but the bearing pre-load makes this one stiff too. Now I'm cutting my losses for a 2nd time - ouch.
Went to a linear bearing supplier to physically check before buying this time. However the seller could not find any type where the bearing would fall under its own weight. All were quite "sticky" due mainly to bearing pre-load, not the wiper seals or the grease.
When touching off on thin metal I need a bearing which will basically will drop under its own weight (plus the weight of the cutting torch). Tom Caudle from Candcnc suggests a counteracting spring to almost pull the torch and bearing back up thereby making the touch of mechanism almost weightless, and so not pushing thin metal down when touching off. This is what I want to do but this requires a bearing which doesn't stick. There are the round bar bearings which seem to fall freely but these require 2 round bar rails to be set up with associated frame.
Anybody had any success with what I am trying to achieve. Is there a particular brand and model of block which is free enough to drop under its own weight.
Thanks,
Keith.