inside countersink responses
Registered Technician in Prosthetics and Orthotics
Description
Collection
Title:
inside countersink responses
Creator:
Registered Technician in Prosthetics and Orthotics
Date:
1/12/2002
Text:
Thanks to all that responded. It was a big help.
Sorry for the delay in posting these
Sean
I bought a realy nice set from msc industrial had i beleive 4 differnat
sizes available..hope this helps..Steve
Sean,
We use a gadget from Otto Bock. They call it the 726W5 Internal Cutter. It
has a 3mm dia. shaft and a 12mm dia. head. It cuts a flat bottomed recess on
the inside if a socket. The head size fits a #6 rivet head. I don't know
what it costs, but if its like most stuff from Otto Bock its probably not
cheap.
Buy the exact size, high quality,(hardened/brittle) drill bits as your desired rivet heads, clamp them in a vise and with a hammer, and safety glasses on, break off two to three inches of the cutting end. Mix some gunk, and create a handle, smooth the handle as desired for your,comfort/grip, and I think you will be very happy with the finished product. The countersink not only matches the angle of the rivet head better, it takes me less than thirty seconds to chamfer/countersink the rivet hole from the inside by hand.
A lot less time than it ever took to chuck,,,assemble,,,pull,,,dissasemble,,,check for fit,,,etc.,,add nauseum,,,,then gunk the inside of a flat bottom hole to match a thirty degree angle rivet head, then regunk over it to smooth the inside of the socket.
If you can find high quality, drill bits, be sure to wear heavy duty work gloves while making your handles, the spirals should be razor sharp.
I'm never confident of my communication skills. If any of this is not clear, give me a call, 1-504-361-1068.
Monty L. Young
I've had the same problem, but have been able to use the smaller shaft with the larger size countersink. It still locks in and does the job
.
Take a look at McMaster-Carr, <URL Redacted>
What you're calling an inside contersink is actually a back spot facer.
If you type in back spot facer (without the quotes), your browser should
take you to several companies that either make them or sell them. If that
doesn't work, go to besly.com and look under their misc. area.
Good luck,
Jim Fenton, CPO, LPO
Really? The set I purchased from Pel Supply has a very small, 1/8, I think,
pilot hole. If you're going to search for it out there, the only
profession that uses the darn things regularly are aircraft assemblers, so a
great tool manufactuere might offer it in their catalog.
Aryeh
I made mine in the engineering workshop at my practice, as I have never seen
any that are adequate on the market.
If you haven't got the gear (lathe, milling machine, oxy-acetylene welding
or TIG, etc, etc....) then why don't you get the nearest engineering jobbing
shop to make some up to your specs. Shouldn't be too pricey.
On the other hand, I could make some for you!
Hope this helps.
Paul X. Stoney
Have you ever tried a Dremel Moto Tool with the round ball shaped bit? We drill the rivet hole then stick the rivet thru the hole on the inside of the project and draw around the head, then use the MOTO on it. Works for us.
Take Care,
Jeff A. Zeller BOCP, RTP
Pel Supply has counter sinks in 1/4 5/16 3/8 7/16 1/2 dia. The
shaft uses a 1/8 hole and is available in 4 length and 6 length.
Al Gullifer
Call Otto Bock they had some not long ago.
Robert Carlile RTPO
Have you tried using friction heat to countersink? For countersinking
plastic cuffs, what you do is, put an appropriate sized rivet (we use 10-32
countersunk screws) through the hole with the shaft sticking outward. Chuck
the rivet shaft into a drill press, turn it on high and hold the cuff
steady. Pull down on it with medium force and allow the rivet to spin and
heat up. It will begin to melt the plastic in the shape of the rivet head.
Be careful not to go too far, of course. You want to ease up on the pressure
when it becomes flush with the plastic. Any remaining plastic edges can be
trimmed with a razor blade.
I don't do prosthetics so I can't tell you how this method would work on a
socket, although I suspect it would not fair well.
At our facility, we try to use the screw head to do the countersinking for
us. The main reason is that the countersinks are not necessarily the exact
same shape as the screw head you are using. When you use the screw head (or
rivet head in your case) to countersink, you can be assured of the most
intimate fit possible. Besides, countersinks cost money. Screws are cheap.
Good luck,
Steve Hill,
We buy them from Cascade, catalog number RSF-100-12 on page 133, listed as a reverse spotfacer, 1/2 inch diameter. They work well - the connection at the end of the pilot shaft is unavoidable a bit fragile, so make sure the shaft is securely mated to the head before using the tool.
A simple and economical way of countersinking is taking a copper rivet and cutting the head towards the shaft with a side cutters creating groves in the shape of pie slices. Slip the rivet through the predrilled hole and hook up to a variable speed hand drill. Pull the rivet towards the inner surface using whatever speed necessary to cut the material.
This has always worked well for me and provides the perfectly sized countersink.
Joel Kempfer
Check out Dunlap machine products, they make a few differant sizes of back
spot facers and they seem to work pretty well. I know they have a web site
and they advertise in the buisiness news.
Also there is a company called vargas that sells some cool true counter sinks
(they have an angled inside surface usualy 72degrees to match a countersunk
screw) they sell trhough MSC supply. Call me if you don't have a catolog and
I'll give you thier number.
Tony Wickman R.T.(O,P)
Hi Sean, you can get reverse spotface and reverse c-sink with different
size pilot shafts from U.S. industrial tool and supply. WWW.ustool.com
they are an aircraft tool supplier. the aerospace industry has lots of
cool tool I use in my clinic.
Good luck.
Lee Barrus CO
********************
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message.
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questions, send e-mail to the moderator
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OANDP-L is a forum for the discussion of topics
related to Orthotics and Prosthetics.
Public commercial postings are forbidden. Responses to inquiries
should not be sent to the entire oandp-l list.
Sorry for the delay in posting these
Sean
I bought a realy nice set from msc industrial had i beleive 4 differnat
sizes available..hope this helps..Steve
Sean,
We use a gadget from Otto Bock. They call it the 726W5 Internal Cutter. It
has a 3mm dia. shaft and a 12mm dia. head. It cuts a flat bottomed recess on
the inside if a socket. The head size fits a #6 rivet head. I don't know
what it costs, but if its like most stuff from Otto Bock its probably not
cheap.
Buy the exact size, high quality,(hardened/brittle) drill bits as your desired rivet heads, clamp them in a vise and with a hammer, and safety glasses on, break off two to three inches of the cutting end. Mix some gunk, and create a handle, smooth the handle as desired for your,comfort/grip, and I think you will be very happy with the finished product. The countersink not only matches the angle of the rivet head better, it takes me less than thirty seconds to chamfer/countersink the rivet hole from the inside by hand.
A lot less time than it ever took to chuck,,,assemble,,,pull,,,dissasemble,,,check for fit,,,etc.,,add nauseum,,,,then gunk the inside of a flat bottom hole to match a thirty degree angle rivet head, then regunk over it to smooth the inside of the socket.
If you can find high quality, drill bits, be sure to wear heavy duty work gloves while making your handles, the spirals should be razor sharp.
I'm never confident of my communication skills. If any of this is not clear, give me a call, 1-504-361-1068.
Monty L. Young
I've had the same problem, but have been able to use the smaller shaft with the larger size countersink. It still locks in and does the job
.
Take a look at McMaster-Carr, <URL Redacted>
What you're calling an inside contersink is actually a back spot facer.
If you type in back spot facer (without the quotes), your browser should
take you to several companies that either make them or sell them. If that
doesn't work, go to besly.com and look under their misc. area.
Good luck,
Jim Fenton, CPO, LPO
Really? The set I purchased from Pel Supply has a very small, 1/8, I think,
pilot hole. If you're going to search for it out there, the only
profession that uses the darn things regularly are aircraft assemblers, so a
great tool manufactuere might offer it in their catalog.
Aryeh
I made mine in the engineering workshop at my practice, as I have never seen
any that are adequate on the market.
If you haven't got the gear (lathe, milling machine, oxy-acetylene welding
or TIG, etc, etc....) then why don't you get the nearest engineering jobbing
shop to make some up to your specs. Shouldn't be too pricey.
On the other hand, I could make some for you!
Hope this helps.
Paul X. Stoney
Have you ever tried a Dremel Moto Tool with the round ball shaped bit? We drill the rivet hole then stick the rivet thru the hole on the inside of the project and draw around the head, then use the MOTO on it. Works for us.
Take Care,
Jeff A. Zeller BOCP, RTP
Pel Supply has counter sinks in 1/4 5/16 3/8 7/16 1/2 dia. The
shaft uses a 1/8 hole and is available in 4 length and 6 length.
Al Gullifer
Call Otto Bock they had some not long ago.
Robert Carlile RTPO
Have you tried using friction heat to countersink? For countersinking
plastic cuffs, what you do is, put an appropriate sized rivet (we use 10-32
countersunk screws) through the hole with the shaft sticking outward. Chuck
the rivet shaft into a drill press, turn it on high and hold the cuff
steady. Pull down on it with medium force and allow the rivet to spin and
heat up. It will begin to melt the plastic in the shape of the rivet head.
Be careful not to go too far, of course. You want to ease up on the pressure
when it becomes flush with the plastic. Any remaining plastic edges can be
trimmed with a razor blade.
I don't do prosthetics so I can't tell you how this method would work on a
socket, although I suspect it would not fair well.
At our facility, we try to use the screw head to do the countersinking for
us. The main reason is that the countersinks are not necessarily the exact
same shape as the screw head you are using. When you use the screw head (or
rivet head in your case) to countersink, you can be assured of the most
intimate fit possible. Besides, countersinks cost money. Screws are cheap.
Good luck,
Steve Hill,
We buy them from Cascade, catalog number RSF-100-12 on page 133, listed as a reverse spotfacer, 1/2 inch diameter. They work well - the connection at the end of the pilot shaft is unavoidable a bit fragile, so make sure the shaft is securely mated to the head before using the tool.
A simple and economical way of countersinking is taking a copper rivet and cutting the head towards the shaft with a side cutters creating groves in the shape of pie slices. Slip the rivet through the predrilled hole and hook up to a variable speed hand drill. Pull the rivet towards the inner surface using whatever speed necessary to cut the material.
This has always worked well for me and provides the perfectly sized countersink.
Joel Kempfer
Check out Dunlap machine products, they make a few differant sizes of back
spot facers and they seem to work pretty well. I know they have a web site
and they advertise in the buisiness news.
Also there is a company called vargas that sells some cool true counter sinks
(they have an angled inside surface usualy 72degrees to match a countersunk
screw) they sell trhough MSC supply. Call me if you don't have a catolog and
I'll give you thier number.
Tony Wickman R.T.(O,P)
Hi Sean, you can get reverse spotface and reverse c-sink with different
size pilot shafts from U.S. industrial tool and supply. WWW.ustool.com
they are an aircraft tool supplier. the aerospace industry has lots of
cool tool I use in my clinic.
Good luck.
Lee Barrus CO
********************
To unsubscribe, send a message to: <Email Address Redacted> with
the words UNSUB OANDP-L in the body of the
message.
If you have a problem unsubscribing,or have other
questions, send e-mail to the moderator
Paul E. Prusakowski,CPO at <Email Address Redacted>
OANDP-L is a forum for the discussion of topics
related to Orthotics and Prosthetics.
Public commercial postings are forbidden. Responses to inquiries
should not be sent to the entire oandp-l list.
Citation
Registered Technician in Prosthetics and Orthotics, “inside countersink responses,” Digital Resource Foundation for Orthotics and Prosthetics, accessed November 2, 2024, https://library.drfop.org/items/show/218316.
