Aluminum Tube ID Reaming

[brettba]

I'm in the process of attempting to ream the ID of an aluminum tube to .75 ID, for a length of 28". And obtain roundness of .0003", and size consistent throughout the length.
We're now utilizing a 'mapal' style reamer which gives us the roundness and size results we're after, however the reamer does not consistantly follow the bore. The tool path is such that by the time we get to the end of the tube, the reamer has 'walked' to one side and it does not clean-up the full diameter.
Any input on possible factors that contribute to this 'drift' or 'position error' or methods used in getting this style reamer to follow the bore of a tube would be appreciated.

 

[Like2Strike]

brettba,

My guess is that the results you are seeing is most likely due to chip load in the fluted parts of the reamer. I am assuming that the shaft of the reamer is true and straight.
28" is long way to go!
You may want to try a highly experienced wire EDM company or a Gun Driller. You may be able to get the results you are after.

Live Aloha
Frank M.
Tradewind Resources

http://www.tr-usa.com

 

[ornerynorsk]

if you have an existing bore that meets straightness tolerance, honing is the only way to go on this project of yours. If you are starting out with solid stock, by all means use gundrilling.