Need Info On Reamers

Try KBC Tools. They're on the 'Net, and have a full line of decimal
reamers, which will fit almost any application.

That said, I would chuck the UHMW in a four-jaw chuck on the lathe
and turn the hole using a really sharp HSS bit.

Dan

wrote in message
ps.com...

Try KBC Tools. They're on the 'Net, and have a full line of decimal
reamers, which will fit almost any application.

That said, I would chuck the UHMW in a four-jaw chuck on the lathe
and turn the hole using a really sharp HSS bit.

Dan


No, ya got lost somewhere Dan. The question at this point is how do you
resize a forstner bit by dressing it, and how could it possibly be the ideal
bit to resize.

"Maxwell" wrote

No, ya got lost somewhere Dan. The question at this point is how do you
resize a forstner bit by dressing it, and how could it possibly be the
ideal bit to resize.


Turn down the outside, or grind down the outside. It is a relatively small
height, and all solid, except for one or two small areas.
--
Jim in NC

"Morgans" wrote in message
...

"Maxwell" wrote

No, ya got lost somewhere Dan. The question at this point is how do you
resize a forstner bit by dressing it, and how could it possibly be the
ideal bit to resize.


Turn down the outside, or grind down the outside. It is a relatively
small
height, and all solid, except for one or two small areas.
--
Jim in NC


You are talking about grinding the OD of one of these bad boys?
http://www.woodcraft.com/family.aspx?familyid=8311

Larger pictu
http://www.woodcraft.com/InhancedIma...?FamilyID=8311

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
news:faOdnWsiTthUryjYnZ2dnUVZ_qGjnZ2d@wideopenwest .com...
"Morgans" wrote in message
...

"Maxwell" wrote

No, ya got lost somewhere Dan. The question at this point is how do you
resize a forstner bit by dressing it, and how could it possibly be the
ideal bit to resize.


Turn down the outside, or grind down the outside. It is a relatively
small
height, and all solid, except for one or two small areas.
--
Jim in NC


You are talking about grinding the OD of one of these bad boys?
http://www.woodcraft.com/family.aspx?familyid=8311

Larger pictu
http://www.woodcraft.com/InhancedIma...?FamilyID=8311

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Thanks Geoff, that is the question on my mind too. If you could even find
one that was 11/16, you would have to pull .030 per side off of it to get an
oversized 5/8. If not, you would have to pull .060 per side off of a 3/4. I
don't see how you could do it without a tool grinder.

Maxwell wrote:
"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote in message
news:faOdnWsiTthUryjYnZ2dnUVZ_qGjnZ2d@wideopenwest .com...
"Morgans" wrote in message
...
"Maxwell" wrote

No, ya got lost somewhere Dan. The question at this point is how do you
resize a forstner bit by dressing it, and how could it possibly be the
ideal bit to resize.

Turn down the outside, or grind down the outside. It is a relatively
small
height, and all solid, except for one or two small areas.
--
Jim in NC

You are talking about grinding the OD of one of these bad boys?
http://www.woodcraft.com/family.aspx?familyid=8311

Larger pictu
http://www.woodcraft.com/InhancedIma...?FamilyID=8311

--
Geoff
The Sea Hawk at Wow Way d0t Com
remove spaces and make the obvious substitutions to reply by mail
When immigration is outlawed, only outlaws will immigrate.

Thanks Geoff, that is the question on my mind too. If you could even find
one that was 11/16, you would have to pull .030 per side off of it to get an
oversized 5/8. If not, you would have to pull .060 per side off of a 3/4. I
don't see how you could do it without a tool grinder.



If you own a bench grinder, drill press or dremel equivalent make a
bracket out of sheet metal, phenolic or hardwood to hold the tool. It
sounds a tad Rube Goldburgish but it can be done. I made a few for
grinding lathe tools.

In the case of a rotating bit you need symmetry as much as size. It
seems to me you coulduse a wood block drilled to accept the tool shaft
at one end and drilled to make a pivot point at the other. A simple stop
like a machine screw could serve as an adjustable stop.

Visit a machine shop some time, you'll see some rather clever widgets
made for a one time use. You never know, they might have exactly what
you are looking for.

Dan, U.S. Air Force, retired

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote

You are talking about grinding the OD of one of these bad boys?
http://www.woodcraft.com/family.aspx?familyid=8311


Yep/ That's the type.

Make a widget to hold a small angle grinder on its side, with a pivot and a
screw for advancing the grinder a bit at a time. Make it so that it will
work clamped to a drill press table.

Put the drill bit in the drill press, and push the bit up and down past the
spinning grinder. Advance the grinder a bit at a time, and stop to check
the progress often.

It works. I've done it before. I am a bit "Rube Goldbergish" at times.
That comes in handy, for a homebuilder.

Of course, if you know someone who works in a machine shop, he could do the
job in a tenth of the time. Where's the fun in that, though?
--
Jim in NC

I have a bit of experience that bears directly on this topic.

A while back I made a bunch of linear guides for a control stick
mechanism that used 5/8" steel push-pull tubes. I tried a bunch of
materials before settling on Nylon.

Anyhow, I found that in practice the smallest reasonable clearance hole
for the 5/8" tube was 1/32" oversize - that's 0.656" decimal or 21/32"
fractional. Any smaller, and the combination of crush and misalignment
used up all of the margin and the tube would bind up in the guide. The
1/32" clearance didn't seem to add any appreciable slop to the system,
and ran with reasoanbly low friction.

Another thing to consider is the that a lot of these low-friction
plastics have pretty steep thermal expansion curves. Also, some of them
absorb water and swell up.

If you have relatively low radial loads and you want really, really low
friction, you can go with these low-cost 5/8" ID linear ball bearings
from ACS:

http://www.aircraftspruce.com/catalo...shrodguide.php

I use a lot of them (copies of them, actually), and they're really
sweet. Even with a 12-foot aluminum tube run through five of them, the
friction is so low that the tube slides downhill under its own weight
at angles as low as 2 degrees.

Thanks, Bob K.
http://www.hpaircraft.com/hp-24

Oh, I forgot to mention:

In my experience, steel tubing tends to run a little larger than the
nominal size. Commercial steel tube (the 1/16" wall stuff from the
hardware store) tends to run around 0.020" over, 4130 tends to run
about 0.010" over. That can make a big difference in hole clearances.

Bob K.

"Morgans" wrote in message
...

"Capt. Geoffrey Thorpe" The Sea Hawk at wow way d0t com wrote

You are talking about grinding the OD of one of these bad boys?
http://www.woodcraft.com/family.aspx?familyid=8311


Yep/ That's the type.

Make a widget to hold a small angle grinder on its side, with a pivot and
a screw for advancing the grinder a bit at a time. Make it so that it
will work clamped to a drill press table.

Put the drill bit in the drill press, and push the bit up and down past
the spinning grinder. Advance the grinder a bit at a time, and stop to
check the progress often.

It works. I've done it before. I am a bit "Rube Goldbergish" at times.
That comes in handy, for a homebuilder.

Of course, if you know someone who works in a machine shop, he could do
the job in a tenth of the time. Where's the fun in that, though?
--
Jim in NC

I think you and Dan have had a little too much torpedo juice!