Drilling cross holes

Btroj

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I need to make a few parts with a .226 bore about 1 in deep. There will be a couple of cross holes at 90° in the bore.
I have made similar parts with a larger bore. I drilled the bore undersized, drilled the cross holes, the bored to final size. I still had a few small burrs to deal with where the cross holes met the bore. I usually final lap the bore to size with a split rod, emery, and some oil.
A split rod isn't practical on a .226 hole, least doesn't seem so to me.
I want to see what you guys think of this.
Drill bore undersized. Ream to just under final size. Drill cross holes. Ream bore again with same reamer to remove burrs from drilling cross holes. Final lap to size with brass laps and lapping compound.
Would this work reasonably well? I need final size to be .226-.2265.

Would drilling cross holes undersized then reaming to final size reduce the burrs in the bore? Cross holes are .065.
 
Your going to have some burr no matter what. I would do the .226 to finish then drill cross holes then use the reamer by hand if it felt like it wouldn't oversize the .226. You can use a small ball shaped grinding burr to deburr the cross holes as long as a slight chamfer is ok. I don't think you would get very good results using an ez burr type tool.
 
There will be a total of 4 cross holes all at 90° to the bore. I may well ream to .224, drill the cross holes, then ream to .226 to clean up the burrs and set a final dimension.

What is the best, or easiest, way to polish a hole that small?
 
What kind of accuracy are you trying to achieve? If .0001, then yes, lapping. If .001, then just bore to final diameter after cross drilling. .0005? Depends on good your measuring equipment is and how skilled you are. I can do that without reaming, but if you have the .226 reamer? Why chance it. No need for intermediate reaming step. If boring I would leave it closer to .005 to .007" for the final boring step, not .002. Sometimes too light a cut just pushes the tool out of the way.
 
Looking for accuracy of ..226-.2265. Bore needs to be smooth.
 
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