Small Part Machining

A great place for fasteners in portland area, is Parkrose Hardware. They
have a lot of metric fasteners and everything else..

"The piece is ~20mm L x ~3-4mm D. Drilled and threaded at the center,
perpendicular to the length."

I assume 20 mm L is 20 mm long and the D is depth ? it couldn't be 3-4 mm
diamete..?! How wide ?

I would get a rectagular plate, cut with hacksaw, shape with file, (way
faster then setting it up in a mill) and find a the correct nut. I would
braze, tack tig, etc the nut to the plate. Real proper, would lathe turn
the nut 3-4mm, leave a shoulder and set into hole in plate.

I assume the plate/ nut assembly will fit. If not you could thin the nut
until it does. I would then make sure you get the high strength nut.

3-4 mm of thread is probably not a proper design.

On Thu, Jun 30, 2011 at 10:46 AM, D D PALMER wrote:

> Ouch!
>
> Score another one to the advatages of "numb junk" argument.
>
>
> ------------------------------
> From: sygibson@gmail.com
> Date: Thu, 30 Jun 2011 10:08:20 -0700
>
> To: obra@list.obra.org
> Subject: Re: [OBRA Chat] Small Part Machining
>
>
> I agree with what Jon says. I've broken a seat bolt in the past (during
> rather rigorous mountain biking ... and the results ... were very, very
> painful). I searched high and low for a replacement bolt - and found that
> Chown Hardware in Portland, on SE Stark carries a very very wide selection
> of high quality bolts. I rode using that replacement bolt from Chown for 5
> more years of hard use before retiring that bike.
>
> You do NOT want your seat bolt to break at the wrong time. Trust me.
>
> ~~shane
>
> --
> "Opportunities multiply as they are seized." - Sun Tzu
>
>
> On Thu, Jun 30, 2011 at 9:26 AM, Jon Myers wrote:
>
> I would be very careful picking the material for this part. The parts
> around the seat post tend to be very highly stressed. Often these parts are
> a high strength alloy steel. These parts are typically machined in an
> annealed condition when it is softer and easier to machine. Then the part
> is then heat treated to give it a good mix of hardness, strength and
> ductility. A steel part that is heat treated to full hard can be up to 4
> times as strong as the same part in an annealed (soft) condition.
> -Jon
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
>
>
>
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>


D D PALMER

2011-06-30

Ouch!

Score another one to the advatages of "numb junk" argument.

From: sygibson@gmail.com
Date: Thu, 30 Jun 2011 10:08:20 -0700
To: obra@list.obra.org
Subject: Re: [OBRA Chat] Small Part Machining

I agree with what Jon says. I've broken a seat bolt in the past (during rather rigorous mountain biking ... and the results ... were very, very painful). I searched high and low for a replacement bolt - and found that Chown Hardware in Portland, on SE Stark carries a very very wide selection of high quality bolts. I rode using that replacement bolt from Chown for 5 more years of hard use before retiring that bike.

You do NOT want your seat bolt to break at the wrong time. Trust me.

~~shane
--
"Opportunities multiply as they are seized." - Sun Tzu

On Thu, Jun 30, 2011 at 9:26 AM, Jon Myers wrote:

I would be very careful picking the material for this part. The parts around the seat post tend to be very highly stressed. Often these parts are a high strength alloy steel. These parts are typically machined in an annealed condition when it is softer and easier to machine. Then the part is then heat treated to give it a good mix of hardness, strength and ductility. A steel part that is heat treated to full hard can be up to 4 times as strong as the same part in an annealed (soft) condition.
-Jon
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John Fortes

2011-06-30

It does not sound from the original description that it was the bolt that
failed. It sounds like the rod that was tapped for the bolt to go into
failed. If I understand your description of the broken part, you could try
looking at McMaster-Carr for a hardened SS dowel pin and then get it tapped
to the correct thread of the bolt that you have. The higher the
ultimate yield strength the better. No need to go cheap if all you need is
one.

On Thu, Jun 30, 2011 at 10:08 AM, Shane Gibson wrote:

>
> I agree with what Jon says. I've broken a seat bolt in the past (during
> rather rigorous mountain biking ... and the results ... were very, very
> painful). I searched high and low for a replacement bolt - and found that
> Chown Hardware in Portland, on SE Stark carries a very very wide selection
> of high quality bolts. I rode using that replacement bolt from Chown for 5
> more years of hard use before retiring that bike.
>
> You do NOT want your seat bolt to break at the wrong time. Trust me.
>
> ~~shane
>
> --
> "Opportunities multiply as they are seized." - Sun Tzu
>
>
>
> On Thu, Jun 30, 2011 at 9:26 AM, Jon Myers wrote:
>
>> I would be very careful picking the material for this part. The parts
>> around the seat post tend to be very highly stressed. Often these parts are
>> a high strength alloy steel. These parts are typically machined in an
>> annealed condition when it is softer and easier to machine. Then the part
>> is then heat treated to give it a good mix of hardness, strength and
>> ductility. A steel part that is heat treated to full hard can be up to 4
>> times as strong as the same part in an annealed (soft) condition.
>> -Jon
>> _______________________________________________
>> OBRA mailing list
>> obra@list.obra.org
>> http://list.obra.org/mailman/listinfo/obra
>> Unsubscribe: obra-unsubscribe@list.obra.org
>>
>
>
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
>
>

--
John P. Fortes

Racing for a cure: http://www.active.com/donate/cycle11national/JFortes


Shane Gibson

2011-06-30

I agree with what Jon says. I've broken a seat bolt in the past (during
rather rigorous mountain biking ... and the results ... were very, very
painful). I searched high and low for a replacement bolt - and found that
Chown Hardware in Portland, on SE Stark carries a very very wide selection
of high quality bolts. I rode using that replacement bolt from Chown for 5
more years of hard use before retiring that bike.

You do NOT want your seat bolt to break at the wrong time. Trust me.

~~shane

--
"Opportunities multiply as they are seized." - Sun Tzu

On Thu, Jun 30, 2011 at 9:26 AM, Jon Myers wrote:

> I would be very careful picking the material for this part. The parts
> around the seat post tend to be very highly stressed. Often these parts are
> a high strength alloy steel. These parts are typically machined in an
> annealed condition when it is softer and easier to machine. Then the part
> is then heat treated to give it a good mix of hardness, strength and
> ductility. A steel part that is heat treated to full hard can be up to 4
> times as strong as the same part in an annealed (soft) condition.
> -Jon
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
>


Jon Myers

2011-06-30

I would be very careful picking the material for this part. The parts around the seat post tend to be very highly stressed. Often these parts are a high strength alloy steel. These parts are typically machined in an annealed condition when it is softer and easier to machine. Then the part is then heat treated to give it a good mix of hardness, strength and ductility. A steel part that is heat treated to full hard can be up to 4 times as strong as the same part in an annealed (soft) condition.
-Jon


Thomas Hoffman

2011-06-30

That would be Dave Feldman.

I would also suggest a hardware store and see if you can find one in the
fastener section.

Hubbard Hardware or any other Ace hardware would be a good place to start.

From: "Mark J. Ginsberg"
Reply-To: "Mark J. Ginsberg"
Date: Wed, 29 Jun 2011 22:16:09 -0700 (PDT)
To: David Kuhns ,
Subject: Re: [OBRA Chat] Small Part Machining

> brett flemming at bike gallery
>
> or david,um david, who used to be at bike gallery
>
> Mark J. Ginsberg
> Berkshire Ginsberg, LLC
> Attorneys At Law
> 1216 SE Belmont St.
> Portland, OR 97214
> (503) 542-3000
> Fax (503) 233-6874
> markjginsberg@yahoo.com
> www.bikesafetylaw.com
>
>
>
> From: David Kuhns
> To: obra@list.obra.org
> Sent: Wed, June 29, 2011 5:40:48 PM
> Subject: [OBRA Chat] Small Part Machining
>
> I have a small broken piece from an aero seat post. The piece is not
> available from the manufacturer.
>
> The piece is ~20mm L x ~3-4mm D. Drilled and threaded at the center,
> perpendicular to the length.
>
> I need to drill and tap some threads on a similar piece. I don't know the
> exact specs, but I have the bolt that threads into it for the pitch and
> spacing of the threads and I have half the broken piece for the diameter of
> the rod.
>
> If you are or know someone who is able to machine a piece like this please
> contact me.
>
> Thanks,
> David Kuhns
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
> _______________________________________________ OBRA mailing list
> obra@list.obra.org http://list.obra.org/mailman/listinfo/obra Unsubscribe:
> obra-unsubscribe@list.obra.org


Mark J. Ginsberg

2011-06-30

brett flemming at bike gallery

or david,um david, who used to be at bike gallery

Mark J. Ginsberg
Berkshire Ginsberg, LLC
Attorneys At Law
1216 SE Belmont St.
Portland, OR 97214
(503) 542-3000
Fax (503) 233-6874
markjginsberg@yahoo.com
www.bikesafetylaw.com

________________________________
From: David Kuhns
To: obra@list.obra.org
Sent: Wed, June 29, 2011 5:40:48 PM
Subject: [OBRA Chat] Small Part Machining

I have a small broken piece from an aero seat post. The piece is not available
from the manufacturer.

The piece is ~20mm L x ~3-4mm D. Drilled and threaded at the center,
perpendicular to the length.

I need to drill and tap some threads on a similar piece. I don't know the exact
specs, but I have the bolt that threads into it for the pitch and spacing of the
threads and I have half the broken piece for the diameter of the rod.

If you are or know someone who is able to machine a piece like this please
contact me.

Thanks,
David Kuhns
_______________________________________________
OBRA mailing list
obra@list.obra.org
http://list.obra.org/mailman/listinfo/obra
Unsubscribe: obra-unsubscribe@list.obra.org


David Kuhns

2011-06-30

I have a small broken piece from an aero seat post. The piece is not available from the manufacturer.

The piece is ~20mm L x ~3-4mm D. Drilled and threaded at the center, perpendicular to the length.

I need to drill and tap some threads on a similar piece. I don't know the exact specs, but I have the bolt that threads into it for the pitch and spacing of the threads and I have half the broken piece for the diameter of the rod.

If you are or know someone who is able to machine a piece like this please contact me.

Thanks,
David Kuhns