Author Topic: Scratch/Kit Bash SD  (Read 2096 times)

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6axlepwr

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Scratch/Kit Bash SD
« on: July 24, 2013, 09:57:54 AM »
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A couple weeks ago I received some test laser cut deck and side sill samples. The deck is 0.030" sheet styrene and the side sills are 0.020" sheet styrene. I built one up over the weekend and last night I thought I would see what it would take to put an Atlas shell on a Kato chassis. Atlas makes a much better looking shell and it is scale width or at least very, very close. The photo you see is the results. Yes, the clean air room needs to be replaced. I will build a new one from scratch. The components will be cut from other models and the backs wet sanded till I get the correct thickness I want.



It takes a bit of doing to get the shell to fit. You have to remove 0.020" off the frame at the top of the nose. At the top of the hood, you need to remove 0.015" off the frame. On the sides around the motor you need to remove 0.015". This opens the motor cavity completely. There is no metal on either side of the motor.  You need to relocate the frame dimples inside the shell and you need to file the frame bumps down till there is only about 0.010" or so left off the surface of the frame. The Atlas shells are thick which is good. The final thing that needs to be done is the copper pickup strips on the DCC board need to be removed. They stick out to far. I will bring wire up from the motor pickups and solder them to the DCC board.

All the metal cutting I did on my mill. All went very well. To relocate the dimples on the inside of the shell, I placed the shell over the frame where it is supposed to be. I then squeezed the shell between my thumb and forefinger. This created a small dimple on the inside of the shell. I then used a motor tool with a steel ball cutter and cut a new dimple. Cut it deep. Once that is done, the shell slips over and locks down nicely.

The way you see the model now. The deck is set at the prototype 63" off the rail head. The width of the new deck is a scale 10'. Per this chart, http://www.trainweb.org/utahrails/drgw/locolength.html, The deck is a scale 61' - 7.5" minus 0.020" for end sheets (0.010" each).

The model is actually going to be an SD38. I am waiting for the GP38 shells to arrive. I had a spare GP40 shell so I thought I would see how it would all work. Since last night, a whole new design has evolved for the deck and side sill.

Battery boxes will be taken from a model that has the correct ones. The backs will be sanded down and attached to a block of styrene and glued in place. Steps and step wells will be photo etched as well as the pilot plate. Handrail stanchions will be from the Atlas GP38/40 model with the rails cut off, the heads of the stanchions drilled out and new brass wire bent. Other parts are in development for this model as well as other models.
Brian

SkipGear

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Re: Scratch/Kit Bash SD
« Reply #1 on: July 24, 2013, 10:04:20 AM »
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The loco is looking good but I want the gauge block it is setting on. That would make it so much easier to take measurements.
Tony Hines

6axlepwr

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Re: Scratch/Kit Bash SD
« Reply #2 on: July 24, 2013, 02:18:55 PM »
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I need to make a larger one. This one is only 2" wide by about 7" or 8" long. Not enough room to put a caliper height gauge on. But it works good for now.
Brian

mmagliaro

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Re: Scratch/Kit Bash SD
« Reply #3 on: July 24, 2013, 02:21:22 PM »
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Good going!   I'd like to see photos of the milled frame on the inside of that thing.

ednadolski

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Re: Scratch/Kit Bash SD
« Reply #4 on: July 24, 2013, 02:24:26 PM »
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Looking real good Brian!

Handrail stanchions will be from the Atlas GP38/40 model with the rails cut off, the heads of the stanchions drilled out and new brass wire bent.

How close to scale are the Atlas stanchions?    Also BTW for handrails I prefer the phosphor bronze wire over brass, as it holds up better to handling.

What is your plan for grabirons?   I've been hand-forming mine, but it is a bit tedious..... not to mention, I probably have nearly as many grabirons in my carpet as on my models...  :D


I want the gauge block it is setting on.

+1.   Are you thinking of making these available?


Thanks,
Ed

6axlepwr

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Re: Scratch/Kit Bash SD
« Reply #5 on: July 24, 2013, 02:44:52 PM »
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How close to scale are the Atlas stanchions?

The Atlas ones are very good. The depth is a little thick, but the width is right. They have the best relief and detail. It is just a bit of a pain using multiple magnifiers to pin prick the center for drilling. I am going to have to devise a tool for drilling. Something like I did for HO stanchions.

Quote
Also BTW for handrails I prefer the phosphor bronze wire over brass, as it holds up better to handling.

I will make a note of that and get some.

Quote
What is your plan for grabirons?   I've been hand-forming mine, but it is a bit tedious..... not to mention, I probably have nearly as many grabirons in my carpet as on my models...  :D

Usually I form my own. I was going to use BLMA ones, but the forming tool that gets used flattens the wire. I do not like that. So most likely I will form my own. I'll just make a tool that makes it a little easier.

Quote
+1.   Are you thinking of making these available?

it would be too expensive. I do not have a CNC machine. All my stuff is done by hand. To make them economical, I would have to have a CNC shop make a hundred or hundreds of them in order to sell them at a reasonable price. If there were at least 100 people interested, I could probably get some made at $15 to $20.00 a piece. For myself, I just take a scrap piece of aluminum and cut tracks in it. Every time I go visit our grandson and family in Illinois, I stop at my friendly machine shop and pick up scrap pieces I can use.

Brian

TiVoPrince

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Re: Scratch/Kit Bash SD
« Reply #6 on: July 24, 2013, 05:55:12 PM »
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Reason
you are not using the remarkable Mark4Designs SD38 shells? 
http://www.mark4design.com/html/n__sd_hoods.html

I would also want a gauge block in N/HO about 14 actual inches...
Support fine modeling

6axlepwr

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Re: Scratch/Kit Bash SD
« Reply #7 on: July 24, 2013, 06:10:53 PM »
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Reason
you are not using the remarkable Mark4Designs SD38 shells? 
http://www.mark4design.com/html/n__sd_hoods.html

I would also want a gauge block in N/HO about 14 actual inches...

I knew this question was going to come up. Although Mark4 Designs Makes a variety of SD38 and SD38-2 hoods, the quality of the printing is just not to what I want. It appears they copied Kato's heavier doors and other features. Atlas does a much finer job and the hoods look much better. More to what I want to see. There are mistakes, but those can be fixed such as the bolt plate on the right side of the clean air room. Much to tall.
Brian

Robbman

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Re: Scratch/Kit Bash SD
« Reply #8 on: July 24, 2013, 07:58:15 PM »
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I knew this question was going to come up. Although Mark4 Designs Makes a variety of SD38 and SD38-2 hoods, the quality of the printing is just not to what I want. It appears they copied Kato's heavier doors and other features.

Uh, no.  I designed those shells.  Do you have one in hand?

6axlepwr

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Re: Scratch/Kit Bash SD
« Reply #9 on: July 24, 2013, 08:58:57 PM »
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Uh, no.  I designed those shells.  Do you have one in hand?

I bought one about 5 years ago. The fidelity was not there. I am not knocking your design at all. It is the machine printing it. The 3D models on the site look fantastic. If the 3D printed model looked like the 3D design, I would be all over them. But it is not. Your 3D design looks as good as the Atlas injection molded shells.

Atlas may have its faults, but their mold fidelity is spot on. Yes, they make some inaccurate measurements or placements, but again the molding is beautiful. I do not know what kind of styrene they are using, but is is really nice. It yields a really nice finish. Kato uses ABS which is a turd to work with.

I do nto want to turn this into another 3D printing debate again though. On the super high resolution machines, it is darn near there. Those machines cost a LOT of money and it is expensive to print on them. I know from experience. The cost of those shells from Mar4 Design are not printed on a high $$$$$ super high resolution machine. If they  were, they would cost a lot more. I'll give you an example. Just one scale coupler pocket. Just one costs $35.00. In just the amount of printing in the nose of one of the Mark4 Design shells, is about 4 coupler pockets.

Robbman, I think I know who you are and I know the quality of yor designs. I am not at all complaining about the design.
Brian

johnh35

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Re: Scratch/Kit Bash SD
« Reply #10 on: July 24, 2013, 09:38:39 PM »
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When Mark first started making shells, there was a curve in the beginning and the first couple of shells I purchased had lines in them. Mark made replacements and the surface finish was as good as any Atlas shell. After that purchase, I went back for more and was not disappointed. If your only purchase was 5 years ago, your review is rather misleading today. His shells should are of far better quality than those offered by Shapeways.

Ike the BN Freak

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Re: Scratch/Kit Bash SD
« Reply #11 on: July 24, 2013, 09:56:00 PM »
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I have 2 of the GP39-2 shells from Mark, only thing I "don't like" about them is the etched fans and free standing grabs.  But I don't super detail my rolling stock, the molded on grabs that Kato, Atlas, etc use are all fine for me.

Otherwise I'd say the shells are just as good as the Atlas ones.

Philip H

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Re: Scratch/Kit Bash SD
« Reply #12 on: July 24, 2013, 10:20:22 PM »
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Folks, Brian has a design plan that works for him with the materials he wants.  Even if he were to get a current M4D piece, it might not meet his preferences.  I know its hard to see people reject things we find useful, but I really hope this thread continues to show off his considerable talents, and doesn't become a "crack on each choice because you wouldn't make it" thread.
Philip H.
Chief Everything Officer
Baton Rouge Southern RR - Mount Rainier Division.

"Yes there are somethings that are "off;" but hey, so what." ~ Wyatt

"I'm trying to have less cranial rectal inversion with this." - Ed K.

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packers#1

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Re: Scratch/Kit Bash SD
« Reply #13 on: July 24, 2013, 10:22:55 PM »
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Folks, Brian has a design plan that works for him with the materials he wants.  Even if he were to get a current M4D piece, it might not meet his preferences.  I know its hard to see people reject things we find useful, but I really hope this thread continues to show off his considerable talents, and doesn't become a "crack on each choice because you wouldn't make it" thread.
+1
Sawyer Berry
Clemson University graduate, c/o 2018

johnh35

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Re: Scratch/Kit Bash SD
« Reply #14 on: July 24, 2013, 10:44:22 PM »
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Folks, Brian has a design plan that works for him with the materials he wants.  Even if he were to get a current M4D piece, it might not meet his preferences.  I know its hard to see people reject things we find useful, but I really hope this thread continues to show off his considerable talents, and doesn't become a "crack on each choice because you wouldn't make it" thread.

I do not think it was intended that way. The question was asked and Brian answered. However, his response was based on an experience from five years ago and not representative of the present. As Mark is still offering shells and Brian's commentary would leave some to believe the quality was along the lines of that offered by Shapeways, would you buy Mark's shells based on that review if you didn't have a personal experience? It is not a "crack on choice", only others' differing opinions.