Need help with Delrin

[Marc]

I want to use delrin as sliding guides for my Z axe and 5/16'' steel rod but if I use a 5/16'' drill bit to drill the hole in the delrin, it's way too tight, next drill bit size and it's way too loose, how do you guys do it? Is there a drill bit size between 5/16'' and 21/64'' ?

Thanks, Marc..

[ger21]

I think you need to use a reamer.

[andy_ck87028]

Not sure what delrin is but I have an 8mm rod and bought an 8mm teflon coated bush which fitted into a 10mm hole. Smooth and no slop. Bush cost me $1

Andy

[Marc]

I think you need to use a reamer

What's a reamer ?

Not sure what delrin is but I have an 8mm rod and bought an 8mm teflon coated bush which fitted into a 10mm hole. Smooth and no slop. Bush cost me $1

Delrin(acetal) it's like hard plastic. Bush you mean like bushing ? If it is I may opt for that, delrin is hard to work with

Marc..

[2muchstuff]

Try freezing it first then go back with the drill bit

[Marc]

Try freezing it first then go back with the drill bit

Tried that already and it's still to tight

Thanks, Marc..

[Cold Fusion]

A reamer is a device for creating a close tolerence hole. Drill bits aren't very good about keeping diameters better then +/- 1/64. Go to www.mcmaster.com and search the term reamer. They aren't too expensive for a standard size like that.

[2muchstuff]

With 5/16 being .3125", the next size up is an 8mm (.3150") after that is a letter O drill (.3160"). Do you have a dial caliper available to measure the inside diameter of your block. Delrin does have some springiness to it and will "retract" when you drill thru it. Measure your hole, subtract .3125 from it. Take the difference and subrtact it from the .3150. If that new figure is at or slightly over .3125 you should be ok. Then drill it out with the new bit.

[Marc]

A reamer is a device for creating a close tolerence hole. Drill bits aren't very good about keeping diameters better then +/- 1/64.

Ha, I see, so a 5/16'' reamer would do it. Btw nice machine

Do you have a dial caliper available to measure the inside diameter of your block

Unfortunatly I don't, but eventually

the next size up is an 8mm (.3150")

I'm going to try an 8mm and see what happens, good thing I have spare delrin

Thanks all

Marc..

[Marc]

The 8mm drill bit worked perfectly

Marc..