# 3D print high hood



## bobvandno2 (Nov 4, 2009)

Hello All, Just finished 3d model of a high hood for an Aristocraft GP40 or a SD45. Now to the 3D printer.














Bob V.


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## ewarhol (Mar 3, 2014)

Good job Bob. Some day I'll have to sit down and figure out this 3D printing thing. I've seen really neat things.


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## jimtyp (Jan 2, 2008)

Nice Bob! What software did u use to create the 3D file?


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## Michael Glavin (Jan 2, 2009)

Bob,

Nice rendering...

What are you printing the hood with?

Michael


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## bobvandno2 (Nov 4, 2009)

Hi to All, Here is a final look at my high hood that will be printed through Shapeways. I have to proof form and function. If all goes well there will be three components available the hood itself plus a bell bracket and gab irons













Bib V.


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## bobvandno2 (Nov 4, 2009)

Here is a link to Shapeways for my models more will be added. Any suggestions for needed parts will be added
https://www.shapeways.com/shops/bobs


Bob V.


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## bobvandno2 (Nov 4, 2009)

*Sample Part*

Hello All, Received my sample High Hood from 3D printer form and function passed. The production parts will have a much higher surface finish.
































































URL=http://s35.photobucket.com/user/bobvand/media/highhood_3D_print/DSCF2771.jpg.html]







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## bobvandno2 (Nov 4, 2009)

some more photos



http://s35.photobucket.com/user/bobvand/media/highhood_3D_print/DSCF2750.jpg.html


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## bobvandno2 (Nov 4, 2009)

I am doing a Wide Cab next. Need some opinions. On the High Hood for the finish product I could print with the bell bracket integral with the grab irons or leave them off as separate items. They would need to be glued on afterwards What would be your advise. Also if any one has a part they liked to have made make a suggestion. See the attached rendering for what the High Hood will look like when it's completed.


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## SD90WLMT (Feb 16, 2010)

A standard 116" "Snoot" nose for USA or A/C standard cabs...

Uses most of the info you have now for the high hood...just some juggling around a bit!!!

My 2 cents...I'm building locos with them!!

.....& .. can't wait to see a hi-res print!! Hi hood...!

...thanks for your consideration!

Addendum.....I did some measuring ....the A/C cab ..as used on a SD45 never used a snoot nose....not needed here
The use of a snoot nose on a USA SD40-2 type cab is about 0.060" wider than an A/C nose is..
..so bearing these thoughts in mind....Snoot noses fit both SD40-2 & SD40T-2 style locos. ...

Dirk - DMS Ry...


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## SD90WLMT (Feb 16, 2010)

If possible ... the small side of cab oval shaped air inlets. 

I'd have to find a pic ..if'n your lost...

About 5" x 8" rectangle with round corners...raised ...usually added to later cabs...
They sit a foot or so above the cab floor line.....

Dirk


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## toddalin (Jan 4, 2008)

I don't want to steal your thread, and have a quick question about 3D print plastic that someone may know.

Does anyone know if there is any plastic available that can withstand short-term, periodic contact with gasoline? I've not found any, but may not be looking in the right place.

Thanks


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## Burl (Jan 2, 2008)

Personally, I think grab irons would look better if they were made out of brass wire. However, printing them is a whole lot easier & they are only slightly oversized at 1mm diameter. 

I assume your high res version will be printed in acrylic? If so, they will be easier to break than nylon.


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## Raymond Lam (Jan 2, 2008)

bobvandno2 said:


> I am doing a Wide Cab next. Need some opinions. On the High Hood for the finish product I could print with the bell bracket integral with the grab irons or leave them off as separate items. They would need to be glued on afterwards What would be your advise. Also if any one has a part they liked to have made make a suggestion. See the attached rendering for what the High Hood will look like when it's completed.


Just a humble suggestion.

Not all the short hoods have bells mounted on them（e.g. Southern Rwy diesels), so a "sand filler hatch" should be another option.

Besides, grab irons, bells, bell brackets, sand filler caps, etc. should be provided separately without being gluded on. That would be easier for placing large decals/emblems or lettering.


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## bobvandno2 (Nov 4, 2009)

Thanks guys the details should be left off. This will allow more options at assembly
http://


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## bobvandno2 (Nov 4, 2009)

Hello all, I have a question would a high hood lend itself to be resin cast. Burl I know you are a master at casting. Could I make a two part mold for these. I'd like to try it what do you think.

Bob V.


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## Burl (Jan 2, 2008)

If the back was mostly open, I'd say it would be it would be relatively simple to cast in a two piece mold. Since its not, the main problem I foresee is that you'll have a large plug in the mold that won't want to come out of the inside (top half of the hood). Don't get me wrong, it's do-able - you might have to fight with it & the mold wouldn't last as long.

Just for reference, I had a guy ask about buying some of my AB parts from Shapeways in a large quantity, and it was far cheaper to sell him castings.


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## bobvandno2 (Nov 4, 2009)

Burl, I did some conceptual changes in my model and the back could be open and still achieve the hood interface with the cab. One thing is what would be the best rtv silicone to use the accommodate the remaining features . If the casting will work I will make a mold to 
reduce cost and offer fellow modelers at a reasonable price.


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## Paul Burch (Jan 2, 2008)

I have a question. It may have been asked and I just missed it. What are trhe plastic choices and will they stand up to the sun's UV and heat without warping?


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## Burl (Jan 2, 2008)

I would use MoldMax 40 from smooth-on if I was going to do it. 

One thing I have always found tricky about two-part molds is getting all the resin to flow in before it kicks. The thicker you make the walls of the hood, the better. I wouldn't even try it at less than 1/8", maybe even as thick as 1/4". I would be tempted to print it in acrylic at .100" and build up the inside with plastic or clay to save some cash.


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## bobvandno2 (Nov 4, 2009)

I was going to print in high detail acrylic from shapeways at .150 wall thickness. I have been told it could be filled with a syringe and actually inject it into the mold. One other question Burl what type resin would be best for the parameters Paul Birch suggested. Also here is the link to Shapeways for my model any suggestions would be appreciated. Thanks to Burl and Paul


https://www.shapeways.com/model/2840135/highhood-rev2.html


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## Burl (Jan 2, 2008)

I have tried other resins, but my my go-to is Alumilite Regular. I'm not trying to knock anybody else's product, but Alumilite always gives me consistent results. I've tried others & they looked alright out of the mold, but over a week or two they warped in unpredictable ways.

I have also read of people using syringes to inject the resin, but the pot life on every hobbyist-resin I have ever used has been too short. It may be possible with some of the other products, but its out of my realm of experience.


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## bobvandno2 (Nov 4, 2009)

Hello to all, Is there any interest in if I could make a resin cast high hood from a 3D printed model for about $45 to $50 would there be any interest?
Bob V.


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