[3Dsigns]

I have made some "v-groove" linear guides out of 3/16" cold rolled steel which will be used with the v-grooved Bishop Wisecarver type bearings. I am preparing to drill holes along the rails so they can be mounted to the side of 80/20 aluminum extrusion. I have a drill press and a drill press vise.

1. The rails will be held off the extrusion just a little with short standoffs so that the wheels can clear. How far apart would you recommend the holes/bolts be?

2. I will be using a 1/4" bit and to get them aligned as accurately as possible, should I mark the holes with a center punch before drilling? Or what would you suggest?

Thanks!

[neilw20]

Distance apart? Well that depends on how much weight the rail needs to support.
Center punch, and drill a few sizes under, otherwise the 1/4" bit will almost surely cut oversize, even if it is new.

[3Dsigns]

The rails are 3/16" thick x 1.5" wide, will be standing 'on edge' and will support about 35 lbs max.
Thanks

[neilw20]

On their edge. Well 12" or so would be fine. It is the stability between mountings, in the 3/16" direction that is important for you.