I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?

wrote in message
oups.com...
I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?

I don't advocate this, and don't tell anyone I recommended it in any way,
shape, or form, but...

I had a similar problem about 20 years ago, about ten times deeper than
yours, and I got away with using a single-edge carbide bit (1/2") in my
router. The aluminum was 2024-T4. I set up a very solid and unnecessarily
complicated jig, made of birch plywood and with lots of C-clamps, to make
sure it was all rigid and wouldn't slip. Through trial-and-error I got to
within a couple of thou and then finished it off with a homemade scraper.

Disclaimer: But I think it's all a bad idea. I advise against it...

--
Ed Huntress

Ed Huntress wrote:
wrote in message
oups.com...

I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?


I don't advocate this, and don't tell anyone I recommended it in any way,
shape, or form, but...

Description setup snipped...

Disclaimer: But I think it's all a bad idea. I advise against it...

LOL

It must all be in the bits. In a fit of naive foolishness about twenty
years ago, I placed a router, its bit spinning at 25K RPM against some
..062 aluminum sheet, I only needed to shave off a few thou -- BAM!

The bit was trashed, the aluminum was trashed, and by the grace of God
no blood flowed. I vowed then and there to never try anything involving
hand-held routers and aluminum again.


Ed Huntress wrote:

I don't advocate this, and don't tell anyone I recommended it in any way,
shape, or form, but...

I had a similar problem about 20 years ago, about ten times deeper than
yours, and I got away with using a single-edge carbide bit (1/2") in my
router. The aluminum was 2024-T4. I set up a very solid and unnecessarily
complicated jig, made of birch plywood and with lots of C-clamps, to make
sure it was all rigid and wouldn't slip. Through trial-and-error I got to
within a couple of thou and then finished it off with a homemade scraper.

Disclaimer: But I think it's all a bad idea. I advise against it...

--
Ed Huntress

"Jim Stewart" wrote in message
news:1110163979.1a99282a12befd83a1638360094607ae@t eranews...
Ed Huntress wrote:
wrote in message
oups.com...

I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?


I don't advocate this, and don't tell anyone I recommended it in any
way,
shape, or form, but...

Description setup snipped...

Disclaimer: But I think it's all a bad idea. I advise against it...

LOL


See? I'm learning about the law and newsgroups. I haven't said anything
about this, and it wasn't anything bad, but I wound up in court for a day
two weeks ago, subpoenaed as a witness because of something I said on this
newsgroup two *years* ago. It's led me to re-think Google's NG archiving. I
now hate it.

It's the second time, same issue. The first time, last year, I had to give
recorded testimony. This time I had to sit in the witness chair in court.

I don't want to do it again.

--
Ed Huntress

"Tim Killian" wrote in message
...
It must all be in the bits. In a fit of naive foolishness about twenty
years ago, I placed a router, its bit spinning at 25K RPM against some
.062 aluminum sheet, I only needed to shave off a few thou -- BAM!

The bit was trashed, the aluminum was trashed, and by the grace of God
no blood flowed. I vowed then and there to never try anything involving
hand-held routers and aluminum again.

That's probably the smarter course of action. Because of some revious
experience I knew I'd need a pretty solid fixture, so I went to some lengths
to make sure that was the case. Still, I approached it very carefully,
holding onto the router like a drowning man holding a life ring, and cutting
in small bites.

--
Ed Huntress

....
It's the second time, same issue. The first time, last year, I had to give
recorded testimony. This time I had to sit in the witness chair in court.

I don't want to do it again.

....

Been there, done that. So, has it given you the same total disgust of the
legal profession I came away with?

Karl

"Karl Townsend" remove .NOT to reply wrote
in message nk.net...

...
It's the second time, same issue. The first time, last year, I had to
give
recorded testimony. This time I had to sit in the witness chair in
court.

I don't want to do it again.

...

Been there, done that. So, has it given you the same total disgust of the
legal profession I came away with?

Not in this case. I was really impressed with the judge, a Hispanic woman
who gave both sides plenty of room. I also saw two very clever attorneys at
work.

I've been in court before, though, and in the past I've come away with the
feeling you suggest.

--
Ed Huntress

"Greg O" wrote in message
...

"Ed Huntress" wrote in message
...
"Tim Killian" wrote in message
...
It must all be in the bits. In a fit of naive foolishness about twenty
years ago, I placed a router, its bit spinning at 25K RPM against some
.062 aluminum sheet, I only needed to shave off a few thou -- BAM!

The bit was trashed, the aluminum was trashed, and by the grace of God
no blood flowed. I vowed then and there to never try anything involving
hand-held routers and aluminum again.

That's probably the smarter course of action. Because of some revious
experience I knew I'd need a pretty solid fixture, so I went to some
lengths
to make sure that was the case. Still, I approached it very carefully,
holding onto the router like a drowning man holding a life ring, and
cutting
in small bites.

--
Ed Huntress



I have routed aluminum with wood bits and a variable speed router on low
speed, worked great, but I advise against doing it!
Greg

There's another man who knows the value of caution.

A variable-speed router sounds like a nice thing. When do you use the lower
speeds? With bigger cutters, or are there other purposes for it?

--
Ed Huntress

wrote in message
oups.com...
I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?

I can't visualise from your description exactly what shape the bits you need
to remove are nor do you say what tolerances you are trying to achieve.
However, a skilled operator can work to pretty fine tolerances by hand with
dremel type equipment. Basically what we do when porting cylinder heads. For
very fine work in aluminium I find it easier to use a mounted stone
lubricated with kerosene than a carbide cutter. You can shave away a couple
of thousandths of an inch at a time with care with these.

Pink aluminium oxide ones meant for grinding cast iron are the ones.
Something like a 10mm diameter cylindrical one on a 3mm shank lets you get
into fiddly corners. Used dry on aluminium the pores clog almost instantly
but keep them wet and they can remove material surprisingly well. For flat
surfaces a coarse oilstone also well lubricated with kerosene will remove
high spots in aluminium very well.
--
Dave Baker - Puma Race Engines (www.pumaracing.co.uk)

On Sun, 6 Mar 2005 22:19:21 -0500, "Ed Huntress"
wrote:

"Jim Stewart" wrote in message
news:1110163979.1a99282a12befd83a1638360094607ae@ teranews...
Ed Huntress wrote:
wrote in message
oups.com...

I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?


I don't advocate this, and don't tell anyone I recommended it in any
way,
shape, or form, but...

Description setup snipped...

Disclaimer: But I think it's all a bad idea. I advise against it...

LOL


See? I'm learning about the law and newsgroups. I haven't said anything
about this, and it wasn't anything bad, but I wound up in court for a day
two weeks ago, subpoenaed as a witness because of something I said on this
newsgroup two *years* ago. It's led me to re-think Google's NG archiving. I
now hate it.

It's the second time, same issue. The first time, last year, I had to give
recorded testimony. This time I had to sit in the witness chair in court.

I don't want to do it again.

When the **** settles..some details would be nice.

Gunner

It's better to be a red person in a blue state
than a blue person in a red state. As a red
person, if your blue neighbors turn into a mob
at least you have a gun to protect yourself.
As a blue person, your only hope is to appease
the red mob with herbal tea and marinated tofu.

(Phil Garding)

"Gunner" wrote in message
...

See? I'm learning about the law and newsgroups. I haven't said anything
about this, and it wasn't anything bad, but I wound up in court for a day
two weeks ago, subpoenaed as a witness because of something I said on
this
newsgroup two *years* ago. It's led me to re-think Google's NG archiving.
I
now hate it.

It's the second time, same issue. The first time, last year, I had to
give
recorded testimony. This time I had to sit in the witness chair in court.

I don't want to do it again.

When the **** settles..some details would be nice.

It's not a big deal, and it's not something I'd want to discuss in public.
It was a contract dispute between two companies I had been involved with.
I'll tell you by email.

Imagine my surprise when I was giving testimony in a deposition, discussing
the subject for most of an hour, when an attorney pulls out printed copies
of three or four of my RCM postings that he had found in Google's archives.
I was very glad then that I habitually stick to the truth. g

--
Ed Huntress

Ed Huntress wrote:

"Gunner" wrote in message
...

See? I'm learning about the law and newsgroups. I haven't said anything
about this, and it wasn't anything bad, but I wound up in court for a day
two weeks ago, subpoenaed as a witness because of something I said on

this

newsgroup two *years* ago. It's led me to re-think Google's NG archiving.

I

now hate it.

It's the second time, same issue. The first time, last year, I had to

give

recorded testimony. This time I had to sit in the witness chair in court.

I don't want to do it again.

When the **** settles..some details would be nice.


It's not a big deal, and it's not something I'd want to discuss in public.
It was a contract dispute between two companies I had been involved with.
I'll tell you by email.

Imagine my surprise when I was giving testimony in a deposition, discussing
the subject for most of an hour, when an attorney pulls out printed copies
of three or four of my RCM postings that he had found in Google's archives.
I was very glad then that I habitually stick to the truth. g

I've drilled my whole family never to post
anything on the internet that you wouldn't
want waved in your face 10 years in the future.
Appears to be good advice.

corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

Sounds like a job for a file.

Or put some sandpaper on a large flat surface (such a a piece of glass)
and sand them off by moving the part .

In , on 03/07/05
at 09:55 AM, Jim Stewart said:

I was very glad then that I habitually stick to the truth

How the hell did the attorney recognise "truth"? Surely not a concept
familiar to most of them?
-----------------------------------------------------------

-----------------------------------------------------------

In article ,
Charles A. Sherwood wrote:
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

Sounds like a job for a file.

Or put some sandpaper on a large flat surface (such a a piece of glass)
and sand them off by moving the part .

At the *bottom* of a pocket?

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

I would say you can use a router to clean up the corners. The trick is to
clamp and jig it properly. That is important. It does not take much to
twist and scrap your part or draw blood.

You might also consider working the area by hand with some die files if the
tolerance specs permit this or perhaps you can relieve the part that fits in
the hole on the corners.

--

Roger Shoaf

About the time I had mastered getting the toothpaste back in the tube, then
they come up with this striped stuff.
wrote in message
oups.com...
I have an aluminum part that is shaped like a picture frame. It is 12
inches square and inch thick. It has a 1/2'x1/2" rebate (where the
picture would go if it were a picture frame). Two cutters were used to
make the rebate. The finish cut was made with a larger diameter
cutter(1") than previous cuts (1/2"), and to maintain the smaller
corner radii, the final cut left a small area in the corners that
protrudes above the finished surface by as much as .015 to .020.

What would be a good way to rework some of these parts without sending
them to a machine shop? Could I use a laminate trimmer or router with
some kind of end mill?