View Full Version : Need a little home machinist advice...

01-29-2009, 12:33 AM
I'm trying to ream out the bushings I'm creating using 4130 tubes. I need to ream the bushings for both the rear tailpost and the bottom of the jackscrew.

Any advice for a simple dead-on ream through 3/4 of an inch with a 3/8ths bore. I tried locking in a vice, and the top was perfect, the bottom just slightly off and oblong.

I'm slightly creative and probably the best plagiarizer I know for a good idea when I see one. Any ideas for a simple home shop set up and do this simply for best results? I thought of just holding the tube with a pliers under my drill press and let my hands try to ream it square, but I haven't tried it yet.

01-29-2009, 12:40 AM
I think I know what you are trying to do, maybe. Why don't you ream a 4 or 5 inch section of tubing and them cut to length?

01-29-2009, 12:53 AM
So friggin obvious!!

Of course, that's why I type instead of scratching my head in the garage!

Thanks Snert, excellent idea.

01-29-2009, 02:11 AM
No problem. I didn't spend three years in the fourth grade for nothin.

01-29-2009, 06:17 AM
Are you using a reamer or trying to ream a hole using a drill bit? If using a reamer you should drill the hole first so that it is no more than .015 under the finish size. A sharp reamer will follow the existing hole. If using a drill the same idea applies, step drill in 1/64 increments to your finish size, each drill will then follow the existing hole.

If your making a bunch of bushings try making a simple fixture to hold them. Using your drill press, take a block of aluminum or steel and drill a hole through that allows the bushing to slip in. Then drill and tap a hole from the side that intersects the bushing hole. Slip your bushing in and lock it in place using a screw in the tapped hole. Using your drill press you should get consistent results.

01-29-2009, 11:31 AM
Excellent suggestion. I'll follow it.