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newrailmodels
Engine Wiper
 

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Posted - 04/22/2007 : 3:08:33 PM
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I have too many projects and really shouldn't be doing this, but... I've been playing around with the idea of making some electrical service parts, so last night after reading these posts, I drew up the following:

I think I can get almost all this detail to show up in HO scale, but certainly in O scale, as a white-metal casting. Would you guys be interested in this as a product?
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Country: USA
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LVRALPH
Fireman
   

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Posted - 04/22/2007 : 4:50:33 PM
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I would love some! You can never have to many projects ongoing..Ask me how I know this!
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Edited by - LVRALPH on 04/22/2007 4:51:26 PM |
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belg
Fireman
   

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Posted - 04/22/2007 : 5:32:58 PM
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John, I think a few cooling fins might add a little more interest to the transformers. Are you sizing them to be pole mounted or pad mounted? Thanks alot, Pat
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Country: USA
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Tabooma County Rwy
Fireman
   

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Posted - 04/22/2007 : 9:04:34 PM
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John, you know I'm interested, especially considering where I work. Cooling fins aren't very common on pole mounted transformers, but hey....I don't know of any model padmounted transformers (hint, hint)
John, when you come over, remind me, so we can go through my stash of transformers - I have several different types - might give you some ideas.
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Country: USA
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Auzze
New Hire
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Posted - 04/22/2007 : 9:25:03 PM
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I will take some, how soon can we get them, need some by may 2007..
Stuart
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Country: Australia
| Posts: 37 |
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newrailmodels
Engine Wiper
 

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Posted - 04/23/2007 : 01:40:20 AM
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As I was driving over to a friend's house this afternoon, I was checking out transformers one poles. I saw a whole bunch of transformers, but I didn't find a single transformer with cooling fins. In light industrial areas, I noticed there were often three transformers on a pole, but they also didn't have cooling fins. I'll ask Al more about this when I see him on Friday.
As to when these will be available, no promises.... I've done the 3-D drawings and the next step is to make brass masters and then have a mold made. My guess is that the earliest I could have product would be in June, but again, no promises.
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Country: USA
| Posts: 127 |
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newrailmodels
Engine Wiper
 

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Posted - 04/28/2007 : 01:53:34 AM
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I decided to have some more fun with this. The fins on the bushing are pretty fine, and I wanted to find out if I could make an injection mold in O scale. I wasn't sure I had the ability to make something this fine in O scale (this model is about .6" in diameter), let alone HO scale. Here are the results:

This is just the top part of the transformer, and it's made from three pieces: two bushings and one domed top.
And here is half the mold, made from aluminum:

I actually put two separate molds next to each other. On the left is the mold for the bushing (the thing that looks like an insulator), and on the right is the mold for the domed top.
Now that I've established I can do this, I think I'm going to put more effort into it. I'm also going to see if I can get a reasonable level of detail in HO scale (not sure yet).
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Country: USA
| Posts: 127 |
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JBL
Engine Wiper
 
Premium Member

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Posted - 04/28/2007 : 03:52:03 AM
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quote: Originally posted by newrailmodels
And here is half the mold, made from aluminum:
Do you have any experience how long a mold from aluminum will last? It is said that they wear out quite fast.
Do you have considered making the HO transformers from brass? Should be the best choice for detail.
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Tabooma County Rwy
Fireman
   

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Posted - 04/28/2007 : 11:10:33 AM
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I saw those samples last night and they are very nice! I'm just hoping John can produce them in HO scale......
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Country: USA
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newrailmodels
Engine Wiper
 

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Posted - 04/29/2007 : 01:59:00 AM
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Jens,
Molds made out of aluminum can easily last 10,000 to 50,000 shots when using styrene. The mold life will be shorter if you use glass-filled resins. Fortunately, styrene happens to be very gentle on molds.
I used aluminum for these test molds for two reasons: first, it's cheap, and second it cuts easily. I've used brass in the past, but it's a lot more expensive. These are also test molds, not production molds, so I just made a few parts as a test. I cut these molds and did the tests shots all in one afternoon. I'm going to redesign the parts and make another mold before I decide if I want to put this into production.
As to an HO version, I'm going to try making a mold to see if I can do it. If not, I may make a brass master and have them spin cast. You can get very good quality with spin casting as long as you start with a high-quality master and retire a mold before it gets too worn out.
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Country: USA
| Posts: 127 |
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JBL
Engine Wiper
 
Premium Member

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Posted - 04/29/2007 : 02:27:53 AM
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Thank you John. I am thinking to get something injection molded since a while. Maybe I should consider Aluminum too, since tool steel a just a bit costly for a fun project.
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newrailmodels
Engine Wiper
 

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Posted - 04/29/2007 : 3:04:29 PM
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It turns out that tool steel is now less expensive than aluminum. We have a tool maker cut the molds for our accessories and he said it's actually cheaper now for him to use steel than aluminum. I'm not sure if this would hold for parts with a lot of detail.
I'm using aluminum for my molds simply because it's easier for me to work with than steel. If you're cutting steel, you really need to use coolant fluid, and my milling machine isn't setup for that.
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Country: USA
| Posts: 127 |
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Tim Kerkhoff
Fireman
   

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Posted - 04/29/2007 : 5:50:34 PM
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John,
I will buy 30 or so in HO scale. Just let us know when they are available.
Thanks
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Country: USA
| Posts: 5879 |
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mikethetrainman
Fireman
   

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Posted - 04/29/2007 : 11:02:29 PM
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John this is cool I would add a couple of dozen in HO to my detail parts bin.
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Mike Mace Northern Division of the Santa Fe |
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Country: USA
| Posts: 1842 |
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newrailmodels
Engine Wiper
 

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Posted - 04/30/2007 : 01:06:46 AM
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I think I might be able to do this in HO scale. I just ran some tool path simulations to see if I could do this without really tiny cutters (I'm still shy of really small cutters) and determined that I can probably do it with a .015" diameter ball nose cutter, so I just ordered some. That means I can try making the mold for the HO bushings and see how it turns out, probably next weekend.
This is turning out to be a really fun learning experience. Thanks for getting me started!
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Country: USA
| Posts: 127 |
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