Best Of The TP56/TP70 Kitbash thread N scale

[u18b]

Post a link when ready.  I'm curious how this turns out.

[randgust]

Did a major overhaul on my mechanism.   I had pieces that would run before but nothing was held down.  Getting it both secure and able to be disassembled was a challenge, but its done.

1)  Added thrust washers to the axles to restrict lateral movement and regauged wheels.
2)  Soldered on heavier pickup wipers to center axle
3)  Removed universal to slightly enlarge it
4)  better secured universal knob on worm shaft
5)  Recentered motor on mount
6)  Fabricated new fuel tank from lead chunk.   Pinned to front of truck with .030 brass rod, pinned tank vertically to frame so that it slides into pin mounts on the front to secure the truck solidly to the frame.
7)  Fabricated metal bracket from brass to hold rear of truck onto brass frame and secured with 00-90 screw.  1 screw at cab holds mech. to frame.
8 )  put .040x.040 styrene shims across frame to raise coupler height and lock down frame
9)  Adapted old frame weight to fit around motor top and open area at universal

Now everything is aligned and secured instead of loosely aligned parts that I had at Altoona.    I switched with it the better part of the afternoon and the performance and pickup is solid now, along with the slow speed you'd expect from the gearhead version.   Haven't weighed it again yet.   I'm debating whether or not I should make a mold for a cast cab weight or just piece the lead in there as a one-off.   If anybody out there is even interested in a cast cab weight for this gearhead approach, speak up.

When I did my GE 70-ton weights I cast score marks so that you could literally snap off cab weight if you wanted it open instead of loaded up.  The cab weight behind the windows was removable, sort of like the cab weight in my Climax 18-ton.

I'm not sure how much 'gee whiz' I'm putting into it, but fore & aft headlight LED's are planned.  Should work.

[Catt]

I am going to do one of these in HO first.Why? Because I have everything I need,I don't have to buy a darn thing. 

If I succeed with that then I will attempt a N scale version following the information posted here on TRW.

[u18b]

I am going to do one of these in HO first.Why? Because I have everything I need,I don't have to buy a darn thing. 

If I succeed with that then I will attempt a N scale version following the information posted here on TRW.

I'm pretty sure the HO scale Kato SD40-2 truck is designed essentially the same- so you could build the HO scale switchers about the same way.

[randgust]

Got the cast cab weight mold done, ran a quick pour, weighed it in the model.

57.2 grams assembled now.  That's heavier than a Kato NW2 or an Atlas MP15.   I'm also going to 'short pour' a second weight so that the windows are open and see how that does in comparison.

You'd expect it pulls well and it sure does, but the real benefit is reliable electrical pickup.

[mmagliaro]

I will be very interested to see how this prints. Finding sheet brass in the right thickness around here isn't easy. This could be a great alternative.

Very very true about sheet brass.  I use onlinemetals.com for heavier pieces like a frame,
but I always have to machine them to get the thickness I need, and I realize that having a mill to do that is a lucky privilege.  The stuff comes in 1/32, 1/16, 3/64, 1/8, and so on.  And that's not fine enough steps to get what we usually need.

[u18b]

Got the cast cab weight mold done, ran a quick pour, weighed it in the model.

57.2 grams assembled now.  That's heavier than a Kato NW2 or an Atlas MP15.   I'm also going to 'short pour' a second weight so that the windows are open and see how that does in comparison.

You'd expect it pulls well and it sure does, but the real benefit is reliable electrical pickup.

Randy.... Pics?

Also, will yours be DCC?

[keeper]

I was away on holiday and in the meantime the brass frames arrived. Very nice.
Pics to follow soon. Stay tuned...

[Lemosteam]

I was away on holiday and in the meantime the brass frames arrived. Very nice.
Pics to follow soon. Stay tuned...

@keeper, did you experience any shrinkage?  Back off Sienfeld freaks!   

How dimensionally accurate to the CAD model did the cast part end up?  Just curious.

[u18b]

Pics and info please. 

I'm curious too!

[keeper]

I'm very pleased with the frames. The surface is very smooth and the frames are not brittle because they are cast.

Each frame has a weight of 7 gram.

The dimensions are within the normal tolerance so the shrinkage is not bad.

The frames are nearly 100% flat which is nice.

I made a mistake though...
The measurement of the two small square holes is not correct. This has to be adjusted if someone would want this frame printed.



Sorry for the poor lightning, I need to take some pics in daylight...

Thomas 

[keeper]

Oh, and one more thing...
Each frame came in a velvet pouch!

 

[Lemosteam]

Oh, and one more thing...
Each frame came in a velvet pouch!

 

Noice!  Well isn't that fancy!

I can't remember, did you have these done at Shapeways? Raw,or polished?

[u18b]

I'm very pleased with the frames. The surface is very smooth and the frames are not brittle because they are cast.

Each frame has a weight of 7 gram.

The dimensions are within the normal tolerance so the shrinkage is not bad.

The frames are nearly 100% flat which is nice.

I made a mistake though...
The measurement of the two small square holes is not correct. This has to be adjusted if someone would want this frame printed.



Sorry for the poor lightning, I need to take some pics in daylight...

Thomas 

Provide a link and cost.

I may be interested in getting one.

[Philip H]

Provide a link and cost.

I may be interested in getting one.

I'm definitely interested in getting one.