Reaming

"Fortunat1" wrote in message
.. .
All hand reamers seem to be HSS which would put me back in the same
boat I'm already in so I was tempted by the carbide reamers I saw for
sale.

Suggest you ask someone in the Greater Seattle area to stop by Boeing
Surplus and buy a couple pounds of reamers for you. Last I remember they
were ~$3/lb.

Rich S.

"RST Engineering" wrote in
:

Orval, I ain't a tinbender and don't pretend that I am. However, if
the (for instance) 1/4" hole is a sixty-fourth undersize, it should
come out 0.234". A letter-D drill will take it out to 0.246"
(admittedly with some triangularity) which should significantly cut
into the laser hardened part of the steel, then the reamer only has to
take off the last four thou.

If you want to cut yourself some more leeway, a letter-C drill will
take it out to 0.242 and then you get to ream eight thou.

OK. I did try to file out most of it. My drill supply wouldn't be all that
large and there aren't a lot of places wit a good suply handt to where I
live, but I will try that.

I did try and sharpen the one I have, but it didn't really work. Used a
little slip stone I have for gouges and it was OK for getting the burrs
off, but not so great for sharpening.
I think the quality of the reamer is probably the biggest prob I had.
Anyway, we worked through a few more holes today using the worn one to at
least get some of the harder stuff off and now it'll be relatively easy to
do those holes over when I get a new reamer.

Fortunat1 wrote:
"RST Engineering" wrote in
:

Orval, I ain't a tinbender and don't pretend that I am. However, if
the (for instance) 1/4" hole is a sixty-fourth undersize, it should
come out 0.234". A letter-D drill will take it out to 0.246"
(admittedly with some triangularity) which should significantly cut
into the laser hardened part of the steel, then the reamer only has to
take off the last four thou.

If you want to cut yourself some more leeway, a letter-C drill will
take it out to 0.242 and then you get to ream eight thou.

OK. I did try to file out most of it. My drill supply wouldn't be all that
large and there aren't a lot of places wit a good suply handt to where I
live, but I will try that.

I did try and sharpen the one I have, but it didn't really work. Used a
little slip stone I have for gouges and it was OK for getting the burrs
off, but not so great for sharpening.
I think the quality of the reamer is probably the biggest prob I had.
Anyway, we worked through a few more holes today using the worn one to at
least get some of the harder stuff off and now it'll be relatively easy to
do those holes over when I get a new reamer.

Try Mcmaster.com, the prices aren't the greatest however the quality
and customer service are. I also tend to get next day service if I order
before they start business for the day and don't pay any more than basic
UPS.

Dan, U.S. Air Force, retired

Dan wrote in :



Try Mcmaster.com, the prices aren't the greatest however the
quality
and customer service are. I also tend to get next day service if I
order before they start business for the day and don't pay any more
than basic UPS.

OK, thanks. I'll try 'em tomorrow.

Slow speed as well.

"Orval Fairbairn" wrote in message
news
In article ,
Fortunat1 wrote:

Another stupid question!

Been reaming holes in a few 4130 plates. The reamer worked fine for about
20 holes and then the holes started getting a bit smaller to the point
the
bolts got a bit snug.
In my ignorance I thought this one hand reamer would pretty much last me
the whole project, but it's obvious I'm going to need a half a dozen of
them at least just to do the wing hardware.
I did a bit of searching on the net and found some info on reamers. All
hand reamers seem to be HSS which would put me back in the same boat I'm
already in so I was tempted by the carbide reamers I saw for sale.
So, my question is; can you use a carbide tipped reamer designed for use
in
a lath in a simple drill press effectively? Or, for that matter, can you
use a reamer designed for use in a lathe as a hand reamer?
Or am I just barking up the wrong tree altogether?

By the way, just for info, the holes I've beenreaming are 5/16 and 1/4.
The
material is .090 4130 and the holes were all laser cut about 1/64
undersize. I would ream the first hole in each plate and then clamp
together the plates in pairs to ensure accurate alignment of the holes in
each pair of plates.
Just in case it's not the reamer's fault at all!

Did you use cutting oil? Even plain old lubricating oil helps a lot and
keeps the tool cool.

"Cy Galley" wrote

Slow speed as well.

Exactly.

If people had ever seen some charts comparing varying cutting tool speed and
feed pressure, and the resulting wear on the tool, they would be amazed.

In summary, you run your tools too fast, and they go up in smoke in a hurry.

If you ever have to guess, guess on the side of slower tool speed and more
pressure.

Of course, getting a real chart with the tool, material, and the correct
tool speed and feed speed or pressure it the "best" way to go at it. g
--
Jim in NC

"Morgans" wrote in message
...

If you ever have to guess, guess on the side of slower tool speed and more
pressure.

Amen to that, Jim. Have you ever let a drill bit spin just for a second on
some stainless and work-harden the surface?

Sounds like he is using the reamer correctly, tho. It's just the lasered
skin that's dulling the tool.

Rich S.

"Rich S." wrote

Amen to that, Jim. Have you ever let a drill bit spin just for a second on
some stainless and work-harden the surface?

My downfall is always using a large diameter bit, in a drill press that will
not go slow enough, in thick steel.

It is amazing how you can take the temper out of a 21/32" bit, in just a
couple seconds. DAMHIKT !

Also, I found you can actually get a molten blob of glass on the end of a
regular HSS drill bit. You DO have to try quite hard to do that, tho!
Especially the part of not breaking the glass, in the process. :-o

Sounds like he is using the reamer correctly, tho. It's just the lasered
skin that's dulling the tool.

I guess the answer is probably pretty obvious, but would it be possible to
normalize the steel right around the small area of the hole? Too much loss
of strength?

It does sound like lowering the tool speed would be worth the try, once the
new reamers get there. It will be fairly obvious is the tool speed is too
low, once a few holes are attempted.
--
Jim in NC

Morgans wrote:
"Cy Galley" wrote

Slow speed as well.

Exactly.

If people had ever seen some charts comparing varying cutting tool speed and
feed pressure, and the resulting wear on the tool, they would be amazed.

In summary, you run your tools too fast, and they go up in smoke in a hurry.

If you ever have to guess, guess on the side of slower tool speed and more
pressure.

Of course, getting a real chart with the tool, material, and the correct
tool speed and feed speed or pressure it the "best" way to go at it. g

Of course misidentifying metals is always a gas. Storing hardened
tool steel in the same place as free machining stainless makes for some
rather interesting experiences. Not that I have ever done it or anything

Dan, U.S. Air Force, retired

"Morgans" wrote in
:



Of course, getting a real chart with the tool, material, and the
correct tool speed and feed speed or pressure it the "best" way to
go at it. g

OK, which brings me to another side of this, I guess. I'm hand reaming. By
that I mean I'm putting a tap handle on the reamer, sticking the work piece
in a vice and going at it by twisting the thing by hand. Needless to say
it's nearly impossible to keep the reamer absolutely straight. Am I doing
this right? One suggestion I got was to use my drill press by rigging
something up to hand turn the drill spindle (no way I can get it to turn
slowly enough for reaming) in order to get the reamer straight in.

Is this unneccesarily complicated? We're talking about .090 4130 here with
a 5/16" hole. Wing attach and strut brackets for mounting onto a wooden
spar for the most part..