Well here goes... Aluminium frame router design

[Neale]

No, it isn't safe. DAMHIKTIJKOK.

My carriages came with little plastic slides that fill the hole as you slide the carriage off the rail - not sure if you could use a flat piece of plastic about the right size?

[CharlieRam]

No, it isn't safe. DAMHIKTIJKOK.

My carriages came with little plastic slides that fill the hole as you slide the carriage off the rail - not sure if you could use a flat piece of plastic about the right size?

Just had to google that to find out what you meant!!

[JAZZCNC]

Flat piece of plastic or wood about 3mm thick same width as slot ball fit into with tapered edges will work best. Foam and sponge can let the balls fall out if rails arnt perfectly lined up and push on them wrong.

To be honest thou If those are TBI bearings, which they look like then I think they are held in with plastic cage and don't fall out. The tricky part is putting them back on because you can easily damage the plaistc cage if not careful. . . . Better to be safe than sorry so make.!

[CharlieRam]

The branding on the bearings is PDF, I tried searching for them but couldn't find them online, I got them off Chai before everyone switched to fred! not to sure about the rails, a bit bowed and terrible looking grinding bounce along the profiled angles but they seem smooth enough when moving by hand with a bit of pressure on them. time will tell I suppose.
I'm having a right mare trying to machine the faces flat for mounting the rails, it seems I needed a bigger mill because even with the gibstrips adjusted the bed sags with the weight when moving to the extremes of the slideways causing a bowed face so I'm going to clamp it upright and mill with an end mill instead of the flycutter I was using. what this means though is I am more than likely going to have to Epoxy my steel rails cause they are even longer and heavier than the aluminium gantry.

[CharlieRam]

Just put the bearings on my ballscrew for the gantry and gave it a spin, it's a bit bent, the runout on the ends near the bearings is about 0.001" but in the middle it's over 0.020", my DTI doesnt read any more than that but I estimate it to be about 0.030"/0,75mm. Now I can attempt to straighten it on my mill but before I do, What would be considered as a reasonable amount of runout please?
Cheers, Charlie

[JAZZCNC]

Just put the bearings on my ballscrew for the gantry and gave it a spin, it's a bit bent, the runout on the ends near the bearings is about 0.001" but in the middle it's over 0.020", my DTI doesnt read any more than that but I estimate it to be about 0.030"/0,75mm. Now I can attempt to straighten it on my mill but before I do, What would be considered as a reasonable amount of runout please?
Cheers, Charlie

Obviously the ideal is zero or near but I've seen worse work perfectly fine. I'd just fit it before doing anything because I think you'll find the runout won't be noticable when attched to ballnut mount. If you have vibration then it's an easy thing to remove and straighten.