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[GMCnet] How do you measure a radius [message #238442] Sat, 01 February 2014 22:50 Go to next message
USAussie is currently offline  USAussie   United States
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Location: Sydney, Australia
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G'day,

I've promised to provide JohnF with measurements of the GMC. On Friday I was down at the workshop and got started on the windows.
One of the measurements John would like is the radius of the corners.

How do I measure them?

SIMPLE instructions please!

Regards,
Rob M.

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] How do you measure a radius [message #238449 is a reply to message #238442] Sat, 01 February 2014 23:36 Go to previous messageGo to next message
John Olson is currently offline  John Olson   United States
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Registered: August 2013
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Member
Hi Rob,

For measuring window corner radii, I'd use a square scale oriented to each
tangent point, and one leg of scale level with ground plane.

This should produce a close enough reference dim for the model project.
Call out which edge is measured, the remaining measurements of that corner
are concentric.

Sorry for the hand-waving explanation. I can make an image if that will be
more clear.



John Olson
76 Edgemont
Chicago, IL (currently nomadic in AZ)


On Sat, Feb 1, 2014 at 9:50 PM, Robert Mueller <robmueller@iinet.net.au>wrote:

> G'day,
>
> I've promised to provide JohnF with measurements of the GMC. On Friday I
> was down at the workshop and got started on the windows.
> One of the measurements John would like is the radius of the corners.
>
> How do I measure them?
>
> SIMPLE instructions please!
>
> Regards,
> Rob M.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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John Olson 76 Edgemonte Fulltime traveler
Re: [GMCnet] How do you measure a radius [message #238454 is a reply to message #238449] Sun, 02 February 2014 00:16 Go to previous messageGo to next message
John Olson is currently offline  John Olson   United States
Messages: 96
Registered: August 2013
Karma: 0
Member
Here is pic of measuring the window radius.

http://www.gmcmhphotos.com/photos/member-galleries/p52752-radius-measure.html



John


On Sat, Feb 1, 2014 at 10:36 PM, John Olson <johnolsondesign@gmail.com>wrote:

> Hi Rob,
>
> For measuring window corner radii, I'd use a square scale oriented to each
> tangent point, and one leg of scale level with ground plane.
>
> This should produce a close enough reference dim for the model project.
> Call out which edge is measured, the remaining measurements of that corner
> are concentric.
>
> Sorry for the hand-waving explanation. I can make an image if that will be
> more clear.
>
>
>
> John Olson
> 76 Edgemont
> Chicago, IL (currently nomadic in AZ)
>
>
> On Sat, Feb 1, 2014 at 9:50 PM, Robert Mueller <robmueller@iinet.net.au>wrote:
>
>> G'day,
>>
>> I've promised to provide JohnF with measurements of the GMC. On Friday I
>> was down at the workshop and got started on the windows.
>> One of the measurements John would like is the radius of the corners.
>>
>> How do I measure them?
>>
>> SIMPLE instructions please!
>>
>> Regards,
>> Rob M.
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>>
>
>
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John Olson 76 Edgemonte Fulltime traveler
Re: [GMCnet] How do you measure a radius [message #238461 is a reply to message #238454] Sun, 02 February 2014 07:26 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

Thanks!

Now I don't have to let everybody know what a dummy I was cause I didn't understand your first message!

Oops! ;-)

Regards,
Rob M.
Sydney, Australia

-----Original Message-----
From: John Olson

Here is pic of measuring the window radius.

http://www.gmcmhphotos.com/photos/member-galleries/p52752-radius-measure.html

John


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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] How do you measure a radius [message #238504 is a reply to message #238461] Sun, 02 February 2014 12:10 Go to previous messageGo to next message
SeanKidd is currently offline  SeanKidd   United States
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Registered: June 2012
Location: Northern Neck Virginia
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Senior Member
Thanks for the concise explanation and pictures, I feel a little smarter now.

Sean and Stephanie
73 Ex-CanyonLands 26' #317 "Oliver"
Hubler 1-Ton, Quad-Bags, Rear Disc, Reaction Arms, P.Huber TBs, 3.70:1 LSD Honda 6500 inverter gen.
Colonial Travelers
Re: [GMCnet] How do you measure a radius [message #238573 is a reply to message #238461] Sun, 02 February 2014 18:58 Go to previous messageGo to next message
John Olson is currently offline  John Olson   United States
Messages: 96
Registered: August 2013
Karma: 0
Member
Glad I could help return even a small bit if what I've rec'd from you fine
folks.

The clay modeling wizards at GM taught me how they accurately measure
anything on a vehicle.

Compound curves will be beyond most folks mechanical set ups, though
simplistically it's finding the tanget points while measuring a 3rd point
on the surface between them.

Well, that was more indecipherable hand-waving. Sorry.

Let me know if you run into other measuring challenges and I'll see if I
can help.


On Sunday, February 2, 2014, Robert Mueller <robmueller@iinet.net.au> wrote:

> John,
>
> Thanks!
>
> Now I don't have to let everybody know what a dummy I was cause I didn't
> understand your first message!
>
> Oops! ;-)
>
> Regards,
> Rob M.
> Sydney, Australia
>
> -----Original Message-----
> From: John Olson
>
> Here is pic of measuring the window radius.
>
>
> http://www.gmcmhphotos.com/photos/member-galleries/p52752-radius-measure.html
>
> John
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>


--
John Olson

Cell | 773.315.9220
Skype | johnolsondesign
http://www.linkedin.com/in/johnolsondesign
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John Olson 76 Edgemonte Fulltime traveler
Re: [GMCnet] How do you measure a radius [message #238619 is a reply to message #238573] Mon, 03 February 2014 10:57 Go to previous messageGo to next message
bryant374 is currently offline  bryant374   United States
Messages: 563
Registered: May 2004
Location: Pleasant Valley, NY 12569
Karma: 1
Senior Member
John Olson

Glad I could help return even a small bit if what I've rec'd from you fine
folks.

The clay modeling wizards at GM taught me how they accurately measure anything on a vehicle.

Compound curves will be beyond most folks mechanical set ups, though
>
>




John, your response is very interesting and here is why. I have had many discussions with Mike Lathers & John Locklin on the design of the GMC MH (Mike L, GMC designer & John L, body Engineer). To measure and translate the actual full size clay (RV26) to drawings, body molds, etc. has impressed me. John seemed almost suprised that the first windshield that was fabricated actually fit the prototype GMC body. That "first try" success seemed to be very important to him (keep in mind there was little if any computer assistance).

I would be interested to hear your experiences along this line and how this was accomplished "in the old days"

Thanks,
Bill




Bill Bryant
PO 1976~PB (owned 34 years)
1914 Ford (owned 70 years)
1965 Corvette (owned 39 years)
GMC Motorhome History
Re: [GMCnet] How do you measure a radius [message #238647 is a reply to message #238619] Mon, 03 February 2014 15:55 Go to previous messageGo to next message
John Olson is currently offline  John Olson   United States
Messages: 96
Registered: August 2013
Karma: 0
Member
Hi Bill,

The apparatus I mentioned for measuring automotive surfaces is in the
linked pic.

http://www.gmcmhphotos.com/photos/member-galleries/p52775-automotive-surface-dev.html

I'd love to talk with those gents you mentioned about the development of
the GMC MH. Either could provide much better information than I could on
the subject of Automotive Surface development. That was, and still is,
quite an accomplishment to get a first-pass fit of anything, though I've
never tried a window.

My GM experience was as a clay modelling intern in 1990 (I'm 45), so not
too far into 'the old days'. We did still use most of that equipment shown
in the photo. Amazingly tight toleranced machining on those Angles and
Rails. The machine shop had a crew that specialized in installation of
Rails in a studio around a new buck.

During that time I was able to get personal instruction from the
experienced craftsmen, one had worked during Harley Earl's tenure. As a
result of their tutelage, I still prefer hand tools to powered ones - more
control over fit and finish.



John Olson
76 Edgemont
Chicago, IL (currently nomadic in AZ)


On Mon, Feb 3, 2014 at 9:57 AM, Bill Bryant <bryant374@earthlink.net> wrote:

>
>
> John Olson
>
> Glad I could help return even a small bit if what I've rec'd from you fine
> folks.
>
> The clay modeling wizards at GM taught me how they accurately measure
> anything on a vehicle.
>
> Compound curves will be beyond most folks mechanical set ups, though
> >
> >
>
>
>
>
> John, your response is very interesting and here is why. I have had many
> discussions with Mike Lathers & John Locklin on the design of the GMC MH
> (Mike L, GMC designer & John L, body Engineer). To measure and translate
> the actual full size clay (RV26) to drawings, body molds, etc. has
> impressed me. John seemed almost suprised that the first windshield that
> was fabricated actually fit the prototype GMC body. That "first try"
> success seemed to be very important to him (keep in mind there was little
> if any computer assistance).
>
> I would be interested to hear your experiences along this line and how
> this was accomplished "in the old days"
>
> Thanks,
> Bill
>
>
>
> --
> Bill Bryant
> 1976~PB
> 1914 Ford
> 1965 Corvette
> GMC MH History CD
> GMC Showroom Films DVD
> http://bdub.net/billbryant/
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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John Olson 76 Edgemonte Fulltime traveler
Re: [GMCnet] How do you measure a radius [message #238677 is a reply to message #238647] Mon, 03 February 2014 19:06 Go to previous messageGo to next message
corleyw is currently offline  corleyw   United States
Messages: 130
Registered: June 2007
Location: Battle Ground, WA
Karma: 0
Senior Member
I always thought the best way to find a radius of something like a GMC window corner was to find a soup can, coffee can, gallon can, or whatever can just fit the radius, measure it and divide by two. Measuring a radius can be very tricky... JMHO

Corley '76 Glenbrook 29 other vehicles
Re: [GMCnet] How do you measure a radius [message #238678 is a reply to message #238647] Mon, 03 February 2014 19:15 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
John,

Really cool photo of the clay model of the Toronado!

Regards,
Rob M.
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426

-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of John Olson

Hi Bill,

The apparatus I mentioned for measuring automotive surfaces is in the
linked pic.

http://www.gmcmhphotos.com/photos/member-galleries/p52775-automotive-surface-dev.html

I'd love to talk with those gents you mentioned about the development of
the GMC MH. Either could provide much better information than I could on
the subject of Automotive Surface development. That was, and still is,
quite an accomplishment to get a first-pass fit of anything, though I've
never tried a window.

My GM experience was as a clay modelling intern in 1990 (I'm 45), so not
too far into 'the old days'. We did still use most of that equipment shown
in the photo. Amazingly tight toleranced machining on those Angles and
Rails. The machine shop had a crew that specialized in installation of
Rails in a studio around a new buck.

During that time I was able to get personal instruction from the
experienced craftsmen, one had worked during Harley Earl's tenure. As a
result of their tutelage, I still prefer hand tools to powered ones - more
control over fit and finish.

John

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] How do you measure a radius [message #238707 is a reply to message #238619] Mon, 03 February 2014 22:19 Go to previous message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
""John, your response is very interesting and here is why. I have had many discussions with Mike Lathers & John Locklin on the design of the GMC MH (Mike L, GMC designer & John L, body Engineer). To measure and translate the actual full size clay (RV26) to drawings, body molds, etc. has impressed me. John seemed almost suprised that the first windshield that was fabricated actually fit the prototype GMC body. That "first try" success seemed to be very important to him (keep in mind there was little if any computer assistance).

I would be interested to hear your experiences along this line and how this was accomplished "in the old days"

Thanks,
Bill ""

Bill, once a clay was to the point that everyone was happy with it (usually after die-noking the surface with a film that made it look like a painted surface) the clay would move out of the design studio to a separate area within design staff to be mechanically scanned.That would take days to weeks. At that point design staff engineers would perform the initial critique to determine whether the surfaces and cut lines were do-able. Then drawings would be transferred to the engineers at the divisions (front sheet metal went to the divisional engineers while everything from the A pillar back went to Fisher Body. At that point there would be a lot of give and take to make the design manufacturable and less expensive. However, light duty trucks where done by Chevrolet, and no Fisher Body was involved. GMC had very limited experience and engineered medium and heavy duty trucks and busses. Although I was involved in cars and not the GMC, it was a true "breakout" vehicle for the truck group! Ironically, most of the technology was picked up by the car guys and not the truckers. Alex Mair moved on the Engineering Staff and kept the innovation going.


Bob de Kruyff
78 Eleganza
Chandler, AZ
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