shortening long reamers

[Messinger]

Do any of you shorten your chucking reamers? They all come with such long shafts. I would like to keep the flutes closers to the chuck to try to increase accuracy. Any recomendations on how to cut off some of the shaft (above the flutes) without ruining the reamer (or cutting tool)? I could just put it to a die grinder or bench grinder (cooling as I go), but I thought I'd ask in case there is a more ellegant way I'm not thinking of. Thanks in advance.

-Ben

[MJ Hofbauer]

I don't see why a cut-off wheel wouldn't work. You may temper a small area of the shaft near the cut but since that'll be up in the chuck I can't see it causing any problems. As long as you don't cause so much heat that you warp it. I've had to cut a few tools for use with my mini-lathe and never had a problem. Generally I just used reinforced emery boards with my dremel. -MJ

[Ray Rogers]

I use an air powered cutoff tool with a 3" wheel and heat is no problem and it cuts quickly. I imagine a Dremel would get the job done too ..........

[Messinger]

Thanks guys! I'll give those a try.

-Ben

[L6steel]

Ben, I agree with totally! I never understood why they made the things with such a long shank in the first place. I just put a used 36 grit belt on my Wilton and run it over to the edge of the contact wheel and spin the ream in my fingers till it's ground in two. Then I clean up the end, and round it off. Doesn't take any time at all and I do it bare handed so the ream doesn't get too hot.
I save the section of the shank I cut off and sharpen it to a point. They make great center punches.

[Messinger]

Originally posted by L6steel
I save the section of the shank I cut off and sharpen it to a point. They make great center punches.

What a great idea! Thanks.

-Ben

[Don Robinson]

Ben, I wouldn't cut the shank down. Reamers are made long so they will flex enough to follow the drilled hole. If you make the shank rigid, it may not follow the hole and may not make a round hole.

[Messinger]

Originally posted by Don Robinson
Ben, I wouldn't cut the shank down. Reamers are made long so they will flex enough to follow the drilled hole. If you make the shank rigid, it may not follow the hole and may not make a round hole.

Thanks Don. Hadn't thought of that. It's nice to have a counsulting machinist around. My reamers will keep their long shanks.

-Ben

[Ray Rogers]

That is indeed a good point. As with most things though, there is always more than one way to look at it. In our application - folding knives - the holes are very shallow so a ream wouldn't have much to follow for very long. I like to cut the reamer down so that it is rigid. Then, my knife parts are reamed while secured to a flat surface that is perpendicular to the ream. My aim is to have the reamer not only size the hole but also assure that the sides of the hole are perpendicular to the part being reamed. Maybe it's not the 'proper' use of a ream but it does work very well for me .......

[Frank J Warner]

Ben, I wouldn't cut the shank down. Reamers are made long so they will flex enough to follow the drilled hole. If you make the shank rigid, it may not follow the hole and may not make a round hole.

This is true. If you've ever hit a hole off-center enough with a chucking reamer, you've seen just how much these suckers really do flex!

-Frank J Warner

[Don Robinson]

The key to getting a hole located as precisely as possible lies in always using a center drill or spotting drill to spot the hole location. Then, without moving anything, drill and ream before moving to another hole. Grip the reamer at the very end of the shank, so it can flex if necessary and follow the hole.

A drill has a small flat on the web at the point, which makes the drill walk around until it uses up the flex in the drill, or finds a scratch or surface imperfection. A center drill is very rigid and will not flex, so the hole starts on the right location. The only way to beat that is to bore the hole with a single point tool after drilling undersize, and then grind it.

You can control the size of the reamed hole by reaming dry, which wiil make the largest hole, using water, which will give you a slightly smaller hole, or use tapping fluid if you want a close fit.

Lubricating oil will make a crooked hole which may even be undersize and might sieze on the reamer .

Ream brass and bronze dry. I also drill and ream Ti dry because it actually seems to create less heat than using tapping fluid.:confused:

Now, what else do you need to know?

[alexkuzn]

Originally Posted by Don Robinson

You can control the size of the reamed hole by reaming dry, which wiil make the largest hole, using water, which will give you a slightly smaller hole, or use tapping fluid if you want a close fit.

Lubricating oil will make a crooked hole which may even be undersize and might sieze on the reamer .

Don,

is tapping fluid is the same as cutting oil? I have some cheap cutting oil from Home Depot. Is it OK or I should get something better?

Thanks,
Alex

[rhrocker]

Alex, it should be fine. Please note that the thread you're reading was in Jan of 04. The info contained in it is the same though!

[KnifeWerks]

Originally Posted by Don Robinson

The only way to beat that is to bore the hole with a single point tool after drilling undersize, and then grind it.

You can also do like I was taught as a moldmaker, Center Drill, Drill, then go in with a resharpened endmill, then ream. Holes are always right on then.
If you are having issues, indicate your reamer. Runout will egg shape, and oversize holes.
That's a bigger problem with a short shaft too.

[Don Robinson]

Originally Posted by KnifeWerks

You can also do like I was taught as a moldmaker, Center Drill, Drill, then go in with a resharpened endmill, then ream. Holes are always right on then.
If you are having issues, indicate your reamer. Runout will egg shape, and oversize holes.
That's a bigger problem with a short shaft too.

Brian, that's right. A reamer will always run out slightly in relation to the chuck. The chuck also runs out. The reamer shank is long enough to let the reamer end pick up and follow the original hole. Chuck on the very end of the shank to give it room to flex.

A shortened reamer may ream only one side of the hole and make the result oblong.

Also, reamer shanks aren't hardened. Cut them off with a hack saw if you must.

The whole key for getting a good, true reamed hole is to start with a center drill. Simple.