Reaming

[HuFlungDung]

Originally posted by woody5 What's a floating tap holder?

Its a wooden tap chuck

Actually, it is a chuck that is designed to hold a tap, with some spring loaded flexability in the radial and axial direction. It is commonly used to compensate for lead errors between the tap and the feedrate of the machine's Z axis.

It has a little bit of radial float, too, so it will allow the tap to align itself with a slightly out-of-position hole. Thus, it will work in the same way with a reamer. It is not necessarily the ideal answer, because the tool does wobble a little until it gets started.

[E-Stop]

Originally posted by Bill I will be reaming 6061-T6 90% of the time. I am waiting for reamers to start testing. We will c-dril, drill 31/64, G13 to leave .004 per side, ream .5010. Speed & Feed for the reamer is at 2600rpm and 40ipm, this is in the ball park so we can test. We have a floating tap holder should i G13 the hole to .5000 to get a good start ? Thanks, Bill Johansen

That's a bit fast, Bill. In 6061-T6 reaming a .501 hole I would start at about 688 RPM (90 SFM) and about .012 per rev feed, which would be about 8.25 IPM in this case. Your stock of .004 per side is pretty good. I usually shoot for .004-.006 per side.

I can't stress enough the importance of having a 'good' hole before you ream it. The reamer can only do so much and making sure the pre-reamed hole is good will insure consistency.

[Dan B]

...and never run the reamer backwards when retreating out of the hole.


Dan

[hardmill]

+1 E-STOP
On the speeds & feeds

Also a floating reamer holder is what your after.
A tap driver is a diff. tool.

PEACE

[jonbanquer]

Originally posted by E-Stop That's a bit fast, Bill. In 6061-T6 reaming a .501 hole I would start at about 688 RPM (90 SFM) and about .012 per rev feed, which would be about 8.25 IPM in this case. Your stock of .004 per side is pretty good. I usually shoot for .004-.006 per side. I can't stress enough the importance of having a 'good' hole before you ream it. The reamer can only do so much and making sure the pre-reamed hole is good will insure consistency.

If he's double drilling he should be able to go with less
than .004 to .006 per side. The reason I say this is I often
have to make dull reamers work / last and the less they have
to cut the more they last. Ahhh...you learn so much working
in a small job shop which won't spend a penny on tooling,
machine repair, modern CAD/CAM, proper coolant upkeep, etc.

Of course I'm probably the only one that has to deal with this
situation. LOL :>)

jon

[Ken_Shea]

Hu I have seen your mention of using WD40 on several occasions, do you have good results on other machining uses?
In the firearm business I do my level best to see that no one uses it.
I do like the smell though

I was also kinda taken back at the slow speed and feed recommendations on the reaming of aluminum, having very little experience reaming I would most certainly have started much faster.

Thanks for the tips
Ken (Shea)

[jbtech]

Originally posted by jonbanquer If he's double drilling he should be able to go with less than .004 to .006 per side. The reason I say this is I often have to make dull reamers work / last and the less they have to cut the more they last. Ahhh...you learn so much working in a small job shop which won't spend a penny on tooling, machine repair, modern CAD/CAM, proper coolant upkeep, etc. jon

I think you are confused. What's this about a small shop?

[HuFlungDung]

Originally posted by Ken_Shea Hu I have seen your mention of using WD40 on several occasions, do you have good results on other machining uses? In the firearm business I do my level best to see that no one uses it. I do like the smell though I was also kinda taken back at the slow speed and feed recommendations on the reaming of aluminum, having very little experience reaming I would most certainly have started much faster. Thanks for the tips Ken (Shea)

Hi Ken,

No I don't like to use WD40, but I use it because it seems to work good with reaming. It can also keep a cutter from clogging when doing engraving or small endmill work in aluminum.

I hear it attracts moisture and causes rust after it evaporates. Is this why you do not recommend it?

[Bill]

To the group I have not had time to do testing for the reaming, got asked to work on another project, High Speed Machining of O-1, already talked to Hardmill and set me up.
Thanks again for all the info,Bill Johansen

[Ken_Shea]

"I hear it attracts moisture and causes rust after it evaporates"

You heard right Hu, it will absorb atmospheric moisture after a while, the higher the humidity the quicker it happens. It does make for a fairly good/cheap cleaner and flushes out rust well. WD40 is about 50 years old so its technology is outdated at best. I hear they manufacture 1,000,000 cans a week for the USA alone, pretty impressive actually but I will pick another product for firearms.

[MaximumBob]

I'm trying to ream an accurate hole in a 1/4" thick 6061 Al pulley that I'm making. The finished hole size will be 0.500. How much should a leave for the reamer. Currently the hole is 0.478 which means the chucking reamer will have to ream 0.011" - is this about right? The work is being done in a lathe.

Thanks,

Bob