EMD F7 in SCALE

Where users can chronicle their builds. Start one thread and continue to add on to it.

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Andrew Pugh
Posts: 179
Joined: Wed Jul 12, 2006 9:22 pm
Location: British Columbia, Canada

Re: EMD F7 in SCALE

Post by Andrew Pugh » Thu Jan 07, 2016 1:08 am

I wish you a complete and speedy recovery BDD.

AP

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Benjamin Maggi
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Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: EMD F7 in SCALE

Post by Benjamin Maggi » Thu Jan 07, 2016 1:07 pm

The nose contour looks really well done. Nice job!
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"

Andrew Pugh
Posts: 179
Joined: Wed Jul 12, 2006 9:22 pm
Location: British Columbia, Canada

Re: EMD F7 in SCALE

Post by Andrew Pugh » Tue Aug 23, 2016 6:34 pm

Hello BDD,

I would love to hear more about the build of your F unit if/when you feel up to it.

AP

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BigDumbDinosaur
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Location: Midwestern United States

Re: EMD F7 in SCALE

Post by BigDumbDinosaur » Tue Aug 23, 2016 9:19 pm

Andrew Pugh wrote:I would love to hear more about the build of your F unit if/when you feel up to it.
The eye surgery I had last December was not a success and I no longer have visual acuity in my left eye. I will eventually get back to adding to this topic, but being one-eyed Jack has slowed me down a bit. The priority is to get this locomotive detailed, painted and out of the shop.

Meanwhile here are pics of the front of the unit after I did a test installation of some grab irons.
grab_irons04_reduced.gif
F7 Nose detail
grab_irons01_reduced.gif
F7 Nose Detail
grab_irons03_reduced.gif
F7 Nose Detail
Science makes it known. Engineering makes it work.

fly5150
Posts: 52
Joined: Thu Nov 15, 2012 12:31 pm
Location: Racine, Wisconsin

Re: EMD F7 in SCALE

Post by fly5150 » Wed Aug 24, 2016 12:59 pm

Looking good Bill!
I'll get you those steps when i get back

-Dave

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BigDumbDinosaur
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Re: EMD F7 in SCALE

Post by BigDumbDinosaur » Wed Aug 24, 2016 11:24 pm

fly5150 wrote:Looking good Bill!
I'll get you those steps when i get back

-Dave
Roger that.

Test-fitted the new grilles and they look good. I'll have the old ones boxed and shipped to you in a few days.

Thanks.
Science makes it known. Engineering makes it work.

rrnut-2
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Joined: Mon Jul 18, 2011 7:40 pm
Location: New Hampshire

Re: EMD F7 in SCALE

Post by rrnut-2 » Fri Aug 26, 2016 6:49 am

Looking great! Keep up the good work.

Jim B

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BigDumbDinosaur
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Location: Midwestern United States

Re: EMD F7 in SCALE

Post by BigDumbDinosaur » Fri Aug 26, 2016 9:13 am

rrnut-2 wrote:Looking great! Keep up the good work.

Jim B
Thanks!
Science makes it known. Engineering makes it work.

Glenn Brooks
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Location: Woodinville, Washington

Re: EMD F7 in SCALE

Post by Glenn Brooks » Sat Aug 27, 2016 2:26 am

Would love to know how you built the nose with all the contours ! Great job and superb write up!

Glenn B.
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

fly5150
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Joined: Thu Nov 15, 2012 12:31 pm
Location: Racine, Wisconsin

Re: EMD F7 in SCALE

Post by fly5150 » Sat Aug 27, 2016 9:19 am

Glenn Brooks wrote:Would love to know how you built the nose with all the contours ! Great job and superb write up!

Glenn B.
That is my nose casting that he is using.
See my website below.

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BigDumbDinosaur
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Re: EMD F7 in SCALE

Post by BigDumbDinosaur » Sun Aug 28, 2016 12:45 am

Glenn Brooks wrote:Would love to know how you built the nose with all the contours!
As Dave noted above, he can supply the nose castings.

The nose casting is made from Alumilite, a material that was originally developed for the aircraft industry to facilitate the production of lightweight complex shapes, such as wing tips and wing root fairings, items that previously had to be stamped from aluminum using costly tooling. Alumilite is a two-part resin compound with powdered aluminum dispersed throughout it to give it a remarkable strength-to-weight ratio. It can be machined, drilled and tapped, epoxied and with proper prep, painted to a high gloss finish.

An Alumilite part is made by preparing a silicone rubber mold, mixing the resin with a catalyst and then pouring the mixture into the mold. Depending on which product is used, pot life can be relatively short and the finished part can usually be extracted from the mold in under five minutes. Alumilite is highly exothermic while curing, which means only a limited number of parts can be produced before the mold deteriorates to an unusable state.

As received, the nose casting required relatively little cosmetic work. Most of the cosmetic stuff was in blending the joint between the nose casting and the main part of the steel body, in which I used PC-7 epoxy, arguably the strongest thixotropic epoxy on the market.

The door headlight opening is a modification that Dave devised. Using a jig and hole saw, a large hole is bored through the casting and a short piece of machined PVC pipe is fitted. After prepping the parts with abrasive cloth and acetone, I attached the PVC pipe to the nose with PC-7, using a specially ground putty knife to shape the epoxy into a nice radius.
door_headlight_reduced.gif
Door Headlight After Epoxying
PC-7, like all epoxies, cures faster when heated and since it is a thixotropic compound, heat aids in shaping it. I use an ordinary heat lamp for the purpose. Once fully cured, some sanding was all it took to get it presentable.
Great job and superb write up!
Thanks! Sometimes I fool humans with my smarts routine. :D
Science makes it known. Engineering makes it work.

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makinsmoke
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Re: EMD F7 in SCALE

Post by makinsmoke » Sun Aug 28, 2016 10:04 am

Looking for that website link, Glenn!

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