On Wednesday, March 26, 2014 9:05:42 AM UTC-7, PrecisionmachinisT wrote:
"jon_banquer" wrote in message

...

On Tuesday, March 25, 2014 1:20:36 PM UTC-7, Cydrome Leader wrote:

jon_banquer wrote:



On Tuesday, March 25, 2014 10:41:54 AM UTC-7, Cydrome Leader wrote:



jon_banquer wrote:







On Tuesday, March 25, 2014 10:05:09 AM UTC-7, Cydrome Leader wrote:







jon_banquer wrote:















On Monday, March 24, 2014 12:47:31 PM UTC-7, Cydrome Leader

wrote:















I keep running into an issue with spiral reamers that leave what

appears































to be rifling in anything (aluminum) that I ream.































































changing speed and feed rates doesn't seem to matter. Dry or

with cutting































oil doesn't seem to matter either.































































The straight reamers of the same size don't seem to have this

problem.































































What might be causing this, or how does one stop it?















































Sounds like chip build up on the reamer.































Is it a through hole?































it's through hole. chip build up doesn't seem to be a problem. The

rifling















starts immediately.































Can you stop the reamer and clean it when it pokes through?































yeah, it doesn't appear to be the cause. It will happen at any

depth, be















it 1/4 or an 1".































Usually spiral reamers leave a better finish.































not this one at least.























What are you holding the spiral reamer with?















3 jaw chuck in a tailstock.







Check the alinement of the tailstock. I think something is off. You can

start by doing something like this:







http://www.youtube.com/watch?v=AtYi-mXS4O0







will have to try that rule trick.







shop dog has some great recipies by the way- I tried the apple cake.





It's a great quick check and it is especially helpful in a machining job

shop that has its share of hacks where you share equipment.



I prefer using an indicator in the spindle, attached to a medium lengt rod

so that it can be repositioned, lock the tailpiece and indicate the tail

center at both the retracted and extended positions. This not only centers

the quill but it also tells you whether the quill travel is parallel to the

spindle bearing rotational axis (if it is not parallel then a drill might

line up perfeftly but a reamer will be off-center because a reamer is

typically longer than a drill)



Usually though I just chamfer a bit larger than the reamer and then single

point bore a bit smaller than the reamer for a shallow distance, which

eliminates the problem of reamer wobble on entry....generally works fine

except in exceptionally soft materials since tailstiocks and reamers tend to

flex fairly easily and so they'll tend to follow the hole if you at least

given them a fighting chance.



For cooking I'll stick with Alton Brown. Trying hard not to become a

fanboi but it's hard because I think he's so much better than the rest.


As per usual, excellent machining advice from Precision Machinist.