[Bob La Londe]

After calculating the speed and feed for a chucking reamer do you rapid for the retract, or do you maintain the same speed and feed for the retract?

[keebler303]

I use the same speed for retract. In my experience a rapid retract will tend to leave a spiral score in the bore.

[Bob La Londe]

I use the same speed for retract. In my experience a rapid retract will tend to leave a spiral score in the bore.

I received a reply in another forum from somebody I respect who half agrees with you. Yes a rapid retract will leave a light spiral score mark, but it is superior to allowing the imperfections of the machine, lineup, etc to cut the overall size of the hole larger from a slow retract. You use the reamer to get to a very close to perfect size, but allowing it to wallow around in the hole any longer than absolutely necessary will oversize the hole.

[AARONT]

If your machine is a pos then yes it can ream oversize feeding back out. But chucking reamers are designed to follow the hole so feeding out shouldn't make much of a difference. If you're worried about it reaming over on the feed out and spiral marks you can also stop the spindle then retract.

[keebler303]

If your machine is a pos then yes it can ream oversize feeding back out. But chucking reamers are designed to follow the hole so feeding out shouldn't make much of a difference. If you're worried about it reaming over on the feed out and spiral marks you can also stop the spindle then retract.

But then you have straight marks instead of spiral marks. Ahhh!

[handlewanker]

Hi, I always rapid retract....the reamer is not a boring bar, it is designed primarily to cut a bore to size rapidly as opposed to boring it out with an adjustable boring bar, so as time is the reason you use a reamer......rapid retract.

The fact that you may leave scratch marks on the bore is irrelevant........if the finish is that important, hone it out to size afterwards.
Ian.

[moriboy1]

We feed in and out at the same speed. Size and finish are equally important for most of our parts.


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[handlewanker]

Hi, reamers are designed to cut on the end (corners) not the sides, so withdrawing the reamer will not cut any more material out of the bore, but it will leave a rub mark as the reamer comes up the bore.

If you are feeding the reamer out at the same rate as you feed in you're wasting time which is money.

When a reamer is sharpened it is ground on the corners only.

If you grind the OD of a reamer, you don't have a reamer anymore.....not at that size anyway.
Ian.

[juergenwt]

Hi, reamers are designed to cut on the end (corners) not the sides, so withdrawing the reamer will not cut any more material out of the bore, but it will leave a rub mark as the reamer comes up the bore.

If you are feeding the reamer out at the same rate as you feed in you're wasting time which is money.

When a reamer is sharpened it is ground on the corners only.

If you grind the OD of a reamer, you don't have a reamer anymore.....not at that size anyway.
Ian.

Second that.Juergen

[AARONT]

But then you have straight marks instead of spiral marks. Ahhh!

What if you use a spiral flute reamer...:cheers:

[keebler303]

What if you use a spiral flute reamer...:cheers:

You got me! :wave: