I Need To Make A Quick Reamer For Delrin Bushing Thats Mounted

[davidh]

the title says it, i need to ream a bore to .612 or so, in a bushing thats shrunk a bit when i mounted it in a frame work with a hammer, its about 1" long. i could just carve down a hunk of a broom stick and wrap it with sand paper and put it into a drill but there must be a way to do it and still get a nice smooth surface. . . sand paper really does not leave the surface i would like to have. .
my brain has just hit a brick wall.
its only about .005 too small that came from the smash fit. . . .

 

[RJSakowski]

A 7/16" square comes out to .618. If you milled a square shaft to .433 on a side and tapered it on the end, it should serve as a reamer for Delrin. Leave the corners sharp.

You could also turn a rod to the required diameter and taper the end . Then grind a cutting edge on the tapered section and partially up the straight section. Crude but it should work on Delrin.

 

[GadgetBuilder]

A "D" bit is fairly easy to make and would do the job. No need to harden for use in Delrin. Taper the end slightly to make it easy to start into the existing hole.

The one at the top of the picture below was hardened so it would work in steel.

 

[planeflyer21]

Speaking of D-bits, Clickspring just released a great video on making D-bits:

 

[davidh]

thanks for the replys. i will proceed with a d-shape. . .

 

[george wilson]

I make useful reamers by making the reamer to size,shape,etc.. Then,mill it down exactly in half. I have even chambered pistols like this. I made a half round reamer to ream out peg holes for violin pegs. Half round works fine. And,by working it by hand,you can move a slightly off center hole back into position. Very useful in violin work. Even imported,factory made peg reamers have 3 flutes,and the other side is left blank so you can move holes a little.

 

[Kernbigo]

AS George stated the half ground reamer work great, made some out of tap steel ( m1)

 

[Wreck™Wreck]

You have answered your own question.

If the bore is a critical feature of the part a .612 -0+.0002 chucking reamer may be bought from McMaster for $51.00, if as you say you can open the bore with a wooden dowel and sandpaper then do so, spending an hour or more making an easily available tool is foolish.

 

[tomw]

You can smooth the sanding marks in Delrin with notebook paper on a high speed shaft. It takes awhile...

 

[chips&more]

You can smooth the sanding marks in Delrin with notebook paper on a high speed shaft. It takes awhile...

I thought I tried every trick in the book! A few months ago I tried to polish Delrin with no luck. The best I could get was to leave it alone with the original tool/machine finish. If I touched it with anything else to polish it up. It just made it look worse. I will try the paper idea next time, Thanks!