I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

--
http://www.wescottdesign.com

Thin stock, use scissors. Use copper, brass would be too hard.

On May 30, 6:10*pm, Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. *These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

--http://www.wescottdesign.com

Four options come immediately to mind:

1) Hollow punches, which you could make if you don't already have;

2) Sandwich the copper between sheets of something more sturdy that
you can then machine more "normally", or just laminate it onto a
sturdy substrate (think 'printed circuit board', where they routinely
drill and rout very thin copper that is glued to a fiberglass
substrate).

3) Water jet

4) Laser

p.

On Sat, 30 May 2009 15:36:53 -0700, rangerssuck wrote:

On May 30, 6:10Â*pm, Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. Â*These need to be of thin copper or brass, round, with an OD of
about 9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither
burred nor bent when I'm done?

--http://www.wescottdesign.com

Four options come immediately to mind:

1) Hollow punches, which you could make if you don't already have;

2) Sandwich the copper between sheets of something more sturdy that you
can then machine more "normally", or just laminate it onto a sturdy
substrate (think 'printed circuit board', where they routinely drill and
rout very thin copper that is glued to a fiberglass substrate).

3) Water jet

4) Laser

Water jet and laser are beyond the capabilities of my shop, but the
hollow punches or backing it up with sacrificial material both sound like
viable options.

The punches will leave burrs, I suspect, but if they're even enough I can
beat them flat between flat plates.

--
http://www.wescottdesign.com

No idea on your sizes, but I've been able to use a hand paper
punch that makes single holes for a 3 ring binder that doesn't
bur, bend, or mutilate copper or brass.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"Tim Wescott" wrote in message
...
On Sat, 30 May 2009 15:36:53 -0700, rangerssuck wrote:

On May 30, 6:10 pm, Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm
working
on. These need to be of thin copper or brass, round, with an
OD of
about 9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're
neither
burred nor bent when I'm done?

--http://www.wescottdesign.com

Four options come immediately to mind:

1) Hollow punches, which you could make if you don't already
have;

2) Sandwich the copper between sheets of something more sturdy
that you
can then machine more "normally", or just laminate it onto a
sturdy
substrate (think 'printed circuit board', where they routinely
drill and
rout very thin copper that is glued to a fiberglass substrate).

3) Water jet

4) Laser

Water jet and laser are beyond the capabilities of my shop, but
the
hollow punches or backing it up with sacrificial material both
sound like
viable options.

The punches will leave burrs, I suspect, but if they're even
enough I can
beat them flat between flat plates.

--
http://www.wescottdesign.com

Tim Wescott wrote:
I need to make some head shims/gaskets These need to be of thin copper or brass,

Coat thin copper with resist. Scribe outline of gasket with fine point.
dump in ferric chloride.

Kevin Gallimore

On May 30, 5:10*pm, Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. *These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

--http://www.wescottdesign.com

Ever consider making them from copper wire? Wrap the wire around a
form, make one cut to turn the coil into rings then solder the ends to
make rings

On a different track than most of the answers, I think I would use a dremmil
tool. Just drill the holes undersize and then use grinder stones to bring
them up to ,marked size.

LLB


"Tim Wescott" wrote in message
...
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

--
http://www.wescottdesign.com

You mean these?

Ebay:

370204317171
These are for the .049, but this guy claims to have more parts than
anyone else.

Pete Stanaitis
---------------------------

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

On Sun, 31 May 2009 08:42:24 -0500, spaco wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of
about 9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither
burred nor bent when I'm done?

You mean these?

Ebay:

370204317171
These are for the .049, but this guy claims to have more parts than
anyone else.

Pete Stanaitis
---------------------------

Well, in my case "working on" means "making a new cylinder, piston, rod
and head for fun". The originals may fit, but where's the fun in that?

Besides -- I just called those folks about parts for a .15; they said "no
can do". They just bought out Estes's stock of Cox parts for 1/2 a
million $$, there's reported to be an astonishing amount of oddball stuff
in there, but either they don't have it inventoried yet or the stuff
really isn't there.


--
http://www.wescottdesign.com

"Tim Wescott" wrote in message
...
On Sun, 31 May 2009 08:42:24 -0500, spaco wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of
about 9/16" and an ID of about 1/2".

Hmmm---Glue the copper to a flat surface. I would probably use a piece of
Aluminum flatbar, just because I have a lot of small pieces. Little
superglue on
one surface, make a sandwich and clamp.

Do it in the mill as a vertical trepanning operation. I would use a boring
head.
Grind a very sharp bit and cut the ID of several. Change to an outside bit
and
do the OD. Should leave a very crisp edge with no burr.

Heat, cold, or a razor blade to remove.

Have you tried here? $4 for 3 gaskets.
https://shop.mecoa.com/shopdisplaypr...catalogid=2486

On May 31, 4:42*pm, "Bill Marrs" wrote:
"Tim Wescott" wrote in message

... On Sun, 31 May 2009 08:42:24 -0500, spaco wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. *These need to be of thin copper or brass, round, with an OD of
about 9/16" and an ID of about 1/2".

You can't just turn and part them from an annealed brass water pipe
nipple?

jsw

On Sun, 31 May 2009 14:03:48 -0700, Jim Wilkins wrote:

On May 31, 4:42Â*pm, "Bill Marrs" wrote:
"Tim Wescott" wrote in message

... On Sun, 31 May
2009 08:42:24 -0500, spaco wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm
working on. Â*These need to be of thin copper or brass, round, with
an OD of about 9/16" and an ID of about 1/2".

You can't just turn and part them from an annealed brass water pipe
nipple?

jsw

No -- we're talking shim stock thicknesses here -- 5, 10 mils at most.

The purpose is to adjust the compression of the motor to the particular
fuel and propeller used. Since I'm hacking the cylinder and piston out
of the solid it's especially important -- I have every faith that I'll
get it wrong the first time.

--
www.wescottdesign.com

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox
..09 that I'm
working on. These need to be of thin copper or
brass, round, with
an OD of about 9/16" and an ID of about 1/2".

Jim Wilkins wrote:

You can't just turn and part them from an annealed brass
water pipe
nipple?

jsw

No -- we're talking shim stock thicknesses here -- 5, 10
mils at most.

The purpose is to adjust the compression of the motor to
the particular
fuel and propeller used. Since I'm hacking the cylinder
and piston out
of the solid it's especially important -- I have every
faith that I'll
get it wrong the first time.


I'm on Jim's side on this one. Parting off would give you
good control over
the thickness even though it may be somewhat wasteful due to
the
thickness of the parting tool wasting stock. If the coupound
is not accurate
enough then mount a DTI to set the next cut point. How thin
a piece can
you cut this way? Try it and find out, you might be
surprised .
phil

That seems doable. Buy a stack of brass shims - sheets of brass.

Then select a hole punch of 1/2" and 9/16. These are used on paper,
plastic, leather and the like. The trick will be a firm enough backing
that allows a punch and won't distort.

You can make these - mount them in a drill press and press downward...

Grind pipe or tubing and harden if possible - maybe using an additive.

Or buy them from Cox for your engine :-)
Martin

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

On Sun, 31 May 2009 22:47:33 -0500, Martin H. Eastburn wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of
about 9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither
burred nor bent when I'm done?

That seems doable. Buy a stack of brass shims - sheets of brass.

Then select a hole punch of 1/2" and 9/16. These are used on paper,
plastic, leather and the like. The trick will be a firm enough backing
that allows a punch and won't distort.

You can make these - mount them in a drill press and press downward...

Grind pipe or tubing and harden if possible - maybe using an additive.

Or buy them from Cox for your engine :-) Martin

"Cox" no longer exists. Estes owned the brand but didn't do anything
with it but sell ever less well made and harder to find .049s. They
recently sold a whole warehouse full of stuff to a distributor, although
it's not clear whether they sold the Cox name to go with it.

Besides, I'm making the cylinder, head, rod and piston as a training
exercise. So it may not have _exactly_ the same dimensions as the
original. (It may not run, either -- I just noticed tonight that I had a
pretty serious boo-boo in the port timing. I'm going to finish it off
and give it a whirl; I plan on cheering if the engine can turn under
it's own power. Then I start working on the next one with an eye to all
the lessons I've learned on this one).

--
http://www.wescottdesign.com

On May 31, 8:48*pm, "Phil Kangas" wrote:
Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox
.09 that I'm
working on. These need to be of thin copper or
brass, round, with
an OD of about 9/16" and an ID of about 1/2".

Jim Wilkins wrote:
You can't just turn and part them from an annealed brass
water pipe
nipple?

jsw

No -- we're talking shim stock thicknesses here -- 5, 10
mils at most.

The purpose is to adjust the compression of the motor to
the particular
fuel and propeller used. *Since I'm hacking the cylinder
and piston out
of the solid it's especially important -- I have every
faith that I'll
get it wrong the first time.

I'm on Jim's side on this one. Parting off would give you
good control over
the thickness even though it may be somewhat wasteful due to
the
thickness of the parting tool wasting stock. If the coupound
is not accurate
enough *then mount a DTI to set the next cut point. How thin
a piece can
you cut this way? Try it and find out, you might be
surprised .
phil- Hide quoted text -

- Show quoted text -

I ground the back end of my parting tool thin for jobs like this. The
end needs to be angled very slightly to cut off the work without a
burr, but not enough that the cutting force deflects it sideways. Test
it by shaving less than the tool's width off the end of a rod and
checking if the cut is flat.

jsw

axolotl wrote:
Tim Wescott wrote:
I need to make some head shims/gaskets These need to be of thin
copper or brass,

Coat thin copper with resist. Scribe outline of gasket with fine point.
dump in ferric chloride.

Kevin Gallimore

I second that idea--toner transfer and photoetch printed circuit
methods work for laying the resist pattern. Good for making batches
of parts.

http://www.starshipmodeler.com/tech/fh_pe.htm
http://www.nigellawton009.com/Etchin..._Version_5.htm

Instead of etchant you can use CuSO4 or even salt water, a power
supply, and electrochemically etch parts.

http://steampunkworkshop.com/electroetch.shtml

Cheers,
James Arthur

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

Cut your shim stock in 1" squares.
Cut more than you'll need in a lifetime.
The more the better.

Stack them up and sandwich them between
2 pieces of AL about 1/8" thick. Clamp
well, drill through the center then bore
to the ID.

Turn an arbor for your lathe that will
just fit inside the ID. Drill and tap
a hole in the center of the arbor. Make
some sort of end cap that will hold the
gaskets and AL snugly on the arbor.

Chuck the arbor in your lathe and turn
the whole mess down to the OD.

It won't take as long as it looks. I've
done the whole thing in about 1/2 hour.

On May 31, 4:17*pm, Tim Wescott wrote:
Besides -- I just called those folks about parts for a .15; they said "no
can do". *They just bought out Estes's stock of Cox parts for 1/2 a
million $$, there's reported to be an astonishing amount of oddball stuff
in there, but either they don't have it inventoried yet or the stuff
really isn't there.

Typically when Company #2 buys Company #1's parts stock, they do it
because Company #2 is very familiar with customers who have a
continual and regular need for some subset of the parts stock.

If you were an existing customer of Company #2, you'd probably be on
good terms with someone in sales there and they would know exactly
what you need to buy. If you were not a pre-existing customer of
Company #2, you might very well fall outside their usual customer base
and they could have a hard time figuring out how to deal with you.

Traditional hobby/RC/model stores still do exist and might be able to
get you some Cox parts, but a lot of hobbyists have transitioned to
online web stores which only know about the really cheap Chinese
stuff.

Tim.

On Mon, 01 Jun 2009 10:07:56 -0700, Jim Stewart
wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of about
9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither burred
nor bent when I'm done?

Why not try a car/truck parts shop? A copper seal ring with an I.D. of
1/2 inch ought to be available as they are commonly used on cars and
trucks and diesel injection systems.

Over here you can go into a shop selling car parts with your part in
hand and tell 'em I need a copper ring to fit here. Usually get it
too. :-)

Cheers,

Bruce in Bangkok
(bruceinbangkokatgmaildotcom)

"Phil Kangas"

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox
.09 that I'm
working on. These need to be of thin copper or
brass, round, with
an OD of about 9/16" and an ID of about 1/2".

Jim Wilkins wrote:

You can't just turn and part them from an annealed
brass
water pipe
nipple?

jsw

No -- we're talking shim stock thicknesses here -- 5, 10
mils at most.

The purpose is to adjust the compression of the motor to
the particular
fuel and propeller used. Since I'm hacking the cylinder
and piston out
of the solid it's especially important -- I have every
faith that I'll
get it wrong the first time.


I'm on Jim's side on this one. Parting off would give you
good control over
the thickness even though it may be somewhat wasteful due
to
the
thickness of the parting tool wasting stock. If the
coupound
is not accurate
enough then mount a DTI to set the next cut point. How
thin
a piece can
you cut this way? Try it and find out, you might be
surprised .
phil


Ok, I tried it today on my old SB 9 inch with 932 bronze
bushing
stock that was handy. Parting tool 0.075 wide. Stock was one
inch o.d. w/ a half inch hole. First try got a shim 0.008!
On smaller
dia. stock it would be a lot easier.....phil

Tim Wescott wrote:

"Cox" no longer exists. Estes owned the brand but didn't do anything
with it but sell ever less well made and harder to find .049s. They
recently sold a whole warehouse full of stuff to a distributor, although
it's not clear whether they sold the Cox name to go with it.

Besides, I'm making the cylinder, head, rod and piston as a training
exercise. So it may not have _exactly_ the same dimensions as the
original. (It may not run, either -- I just noticed tonight that I had a
pretty serious boo-boo in the port timing. I'm going to finish it off
and give it a whirl; I plan on cheering if the engine can turn under
it's own power. Then I start working on the next one with an eye to all
the lessons I've learned on this one).


Tim, can you get copper foil with an adhesive back in the right
thickness? If so, a few seconds with an Exacto knife would trim a piece
in place. The foil we used in manufacturing was fairly thin, and stood
up to a hot soldering iron.


--
You can't have a sense of humor, if you have no sense!

Understand Tim.

I'm building - slowly - a bench top size IC engine - a 6-cycle unit.
It is a scale unit and I have to make everything myself also.

Making rings is going to be interesting.

Martin

Tim Wescott wrote:
On Sun, 31 May 2009 22:47:33 -0500, Martin H. Eastburn wrote:

Tim Wescott wrote:
I need to make some head shims/gaskets for a Cox .09 that I'm working
on. These need to be of thin copper or brass, round, with an OD of
about 9/16" and an ID of about 1/2".

Any suggestions on cutting them out evenly so that they're neither
burred nor bent when I'm done?

That seems doable. Buy a stack of brass shims - sheets of brass.

Then select a hole punch of 1/2" and 9/16. These are used on paper,
plastic, leather and the like. The trick will be a firm enough backing
that allows a punch and won't distort.

You can make these - mount them in a drill press and press downward...

Grind pipe or tubing and harden if possible - maybe using an additive.

Or buy them from Cox for your engine :-) Martin

"Cox" no longer exists. Estes owned the brand but didn't do anything
with it but sell ever less well made and harder to find .049s. They
recently sold a whole warehouse full of stuff to a distributor, although
it's not clear whether they sold the Cox name to go with it.

Besides, I'm making the cylinder, head, rod and piston as a training
exercise. So it may not have _exactly_ the same dimensions as the
original. (It may not run, either -- I just noticed tonight that I had a
pretty serious boo-boo in the port timing. I'm going to finish it off
and give it a whirl; I plan on cheering if the engine can turn under
it's own power. Then I start working on the next one with an eye to all
the lessons I've learned on this one).

"Tim Wescott" wrote in message
...
| On Sun, 31 May 2009 22:47:33 -0500, Martin H. Eastburn wrote:
|
| Tim Wescott wrote:
| I need to make some head shims/gaskets for a Cox .09 that I'm working
| on. These need to be of thin copper or brass, round, with an OD of
| about 9/16" and an ID of about 1/2".
|
| Any suggestions on cutting them out evenly so that they're neither
| burred nor bent when I'm done?
|
| That seems doable. Buy a stack of brass shims - sheets of brass.
|
| Then select a hole punch of 1/2" and 9/16. These are used on paper,
| plastic, leather and the like. The trick will be a firm enough backing
| that allows a punch and won't distort.
|
| You can make these - mount them in a drill press and press downward...
|
| Grind pipe or tubing and harden if possible - maybe using an additive.
|
| Or buy them from Cox for your engine :-) Martin
|
| "Cox" no longer exists. Estes owned the brand but didn't do anything
| with it but sell ever less well made and harder to find .049s. They
| recently sold a whole warehouse full of stuff to a distributor, although
| it's not clear whether they sold the Cox name to go with it.
|
| Besides, I'm making the cylinder, head, rod and piston as a training
| exercise. So it may not have _exactly_ the same dimensions as the
| original. (It may not run, either -- I just noticed tonight that I had a
| pretty serious boo-boo in the port timing. I'm going to finish it off
| and give it a whirl; I plan on cheering if the engine can turn under
| it's own power. Then I start working on the next one with an eye to all
| the lessons I've learned on this one).
|
| --
| http://www.wescottdesign.com

Here's one made of brass with the correct ID but larger OD. Each sheet is
..002" thick.
Just trim the OD as necessary for your needs.

http://www.mcmaster.com/#shim-stock/=27hiyu

"R T Smith" wrote in message
...
|
|
|
| "Tim Wescott" wrote in message
| ...
|| On Sun, 31 May 2009 22:47:33 -0500, Martin H. Eastburn wrote:
||
|| Tim Wescott wrote:
|| I need to make some head shims/gaskets for a Cox .09 that I'm working
|| on. These need to be of thin copper or brass, round, with an OD of
|| about 9/16" and an ID of about 1/2".
||
|| Any suggestions on cutting them out evenly so that they're neither
|| burred nor bent when I'm done?
||
|| That seems doable. Buy a stack of brass shims - sheets of brass.
||
|| Then select a hole punch of 1/2" and 9/16. These are used on paper,
|| plastic, leather and the like. The trick will be a firm enough backing
|| that allows a punch and won't distort.
||
|| You can make these - mount them in a drill press and press downward...
||
|| Grind pipe or tubing and harden if possible - maybe using an additive.
||
|| Or buy them from Cox for your engine :-) Martin
||
|| "Cox" no longer exists. Estes owned the brand but didn't do anything
|| with it but sell ever less well made and harder to find .049s. They
|| recently sold a whole warehouse full of stuff to a distributor, although
|| it's not clear whether they sold the Cox name to go with it.
||
|| Besides, I'm making the cylinder, head, rod and piston as a training
|| exercise. So it may not have _exactly_ the same dimensions as the
|| original. (It may not run, either -- I just noticed tonight that I had a
|| pretty serious boo-boo in the port timing. I'm going to finish it off
|| and give it a whirl; I plan on cheering if the engine can turn under
|| it's own power. Then I start working on the next one with an eye to all
|| the lessons I've learned on this one).
||
|| --
|| http://www.wescottdesign.com
|
| Here's one made of brass with the correct ID but larger OD. Each sheet is
| .002" thick.
| Just trim the OD as necessary for your needs.
|
| http://www.mcmaster.com/#shim-stock/=27hiyu
|

Or these : http://www.mcmaster.com/#shim-stock/=27hnpy

On Jun 3, 5:51*pm, "Michael A. Terrell"
wrote:
Tim Wescott wrote:
...
* *Tim, can you get copper foil with an adhesive back in the right
thickness? *If so, a few seconds with an Exacto knife would trim a piece
in place. *The foil we used in manufacturing was fairly thin, and stood
up to a hot soldering iron.

The copper tape for repairing circuit boards is easy to cut into
complex shapes with a razor knife. I've tuned the matching stubs on
stripline circuits with it; cut off a sliver, check it on the network
analyzer, the engineer recalculates the dimensions, etc, over and over
until he gives up. The copper does NOT come off Duroid easily.

For gasket shapes you can carefully trace around the housing with the
knife. It's easier when the housing is steel but I recently cut a
Kynar film to match an ABS form without gouging it. I think you could
turn a lathe fixture that would clamp the sheet between two plugs to
cut the OD, then a hollowed piston and a cylinder with a narrow
internal ridge at the end to clamp the gasket disk while you trim the
ID against the hole in the piston.

jsw

Jim Wilkins wrote:

On Jun 3, 5:51 pm, "Michael A. Terrell"
wrote:
Tim Wescott wrote:
...
Tim, can you get copper foil with an adhesive back in the right
thickness? If so, a few seconds with an Exacto knife would trim a piece
in place. The foil we used in manufacturing was fairly thin, and stood
up to a hot soldering iron.

The copper tape for repairing circuit boards is easy to cut into
complex shapes with a razor knife. I've tuned the matching stubs on
stripline circuits with it; cut off a sliver, check it on the network
analyzer, the engineer recalculates the dimensions, etc, over and over
until he gives up. The copper does NOT come off Duroid easily.


I had to align our ultra low phase noise synthesizers at Microdyne.
They bought some plated brass strip stock for the job, but I preferred
the scrap carrier strip from the smaller AMP & Berg terminals, from the
crimping machines. I used a sharp pair of scissors to trim the tails
left by the terminals. I would tin the ground trace & end of the
inductor of the 510 MHZ VCO, and both ends of the strip. I would take
an initial frequency measurement, then solder the strip to the pair of
traces, to shorten the inductor. After a while, I was within specs the
first try. Since the adjustment was made at the cold end of the
inductor, a pair of hot Edsyn 'Loner' soldering irons let me retune the
board without powering down.

We used several types of self adhesive copper tape to make sure the
machined RF housings had a good RF tight seal. Some was applied to the
face of one part, and trilled around the edges with an Exacto, and
others went over the outside off the seams, after everything was
together. of course, to get the width you needed meant something almost
twice the width, so over half a roll was scrap.


For gasket shapes you can carefully trace around the housing with the
knife. It's easier when the housing is steel but I recently cut a
Kynar film to match an ABS form without gouging it. I think you could
turn a lathe fixture that would clamp the sheet between two plugs to
cut the OD, then a hollowed piston and a cylinder with a narrow
internal ridge at the end to clamp the gasket disk while you trim the
ID against the hole in the piston.


That's a lot simpler than making a custom set of punches.




--
You can't have a sense of humor, if you have no sense!