Producing a new US style loco in TT scale

Re: Producing a new US style loco in TT scale

Postby areibel » Tue Mar 29, 2011 8:34 am

Carsten wrote:They aren't their design. These are H0m tram trucks. I believe they are from Halling.

Thanks Carsten,
I thought they did their own, it didn't look like any of the other stuff I've seen (Tillig, Piko, etc)
Al
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Re: Producing a new US style loco in TT scale-Bowser drives

Postby railtwister » Tue Mar 29, 2011 9:36 am

I just got an eMail reply from a friend who has been an active HO trolley modeler for over 40 years, concerning concerning my inquiry about the Bowser trolley drives. He says the units have been available now for about ten years, they are basically an adaptation of the Athearn HO power truck design, but produced from the ground up to be a 6'6" traction truck. He feels it is a robust unit, and should work well in pairs for a small diesel. Over the time since the truck has become available, he has heard of no major issues or flaws with it's design or use, and he says right out of the box, an HO Bowser trolley should be able to handle an 8" radius curve, and they can be modified with smaller universal joints to go around even tighter radii (I believe his own layout has some 7" curves). The motor that comes in the trolleys is a single shaft can style with no flywheels, which would need to be replaced by a motor with two shafts for use with two power trucks. He also mentioned that ProtoPower West offers an upgrade kit that comes with a better flywheel equipped can motor and smaller u-joints to fit the Bowser trolleys.

It sounds from this information that the Bowser trucks should be well suited for a TT scale F-unit, and if the stock HO trolley can negotiate 8" radius curves, typical TT scale curves of 310mm and 353mm shouldn't be a problem, and maybe even 263mm (10-1/2") radius curves might work, too.

The next question I would have is whether or not these units were being produced for Bowser by Sanda-Kan in China. Last year S-K announced it was canceling it's manufacturing agreements with over 2/3 of it's American clients (about 60 companies) due to overloads resulting in overly long delays in production. They kept their biggest clients like Atlas and Lionel, but axed all of the little guys. If Bowser was one of those "little guys", it may mean that depending on on-hand inventories, there could be a limit to the supply of these drives, or a delay in their production while a new manufacturer is found.

Regards,
Bill
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Re: Producing a new US style loco in TT scale-Bowser drives

Postby ctxmf74 » Tue Mar 29, 2011 12:05 pm

railtwister wrote:It sounds from this information that the Bowser trucks should be well suited for a TT scale F-unit, and if the stock HO trolley can negotiate 8" radius curves, typical TT scale curves of 310mm and 353mm shouldn't be a problem, and maybe even 263mm (10-1/2") radius curves might work, too.


What you need to find out is how wide the truck frame is. From bowser photos it looks like there is very little space between the wheel backs and the truck frame so it may be impossible to narrow the gauge to TT scale? ....dave
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Re: Producing a new US style loco in TT scale-Bowser drives

Postby railtwister » Tue Mar 29, 2011 1:16 pm

ctxmf74 wrote: What you need to find out is how wide the truck frame is. From bowser photos it looks like there is very little space between the wheel backs and the truck frame so it may be impossible to narrow the gauge to TT scale? ....dave


Hi Dave,

I agree that there is no substitute for first hand examination of the truck and it's dimensions, but I thought I read somewhere that Elmer Mckay had already used one of the drives in one of his TT scale projects (someone please correct me if I'm wrong here). Lately, I've been kept pretty busy (and broke) building eight T-Trak-TT modules using Tillig's Bedding Track, but as soon as I get them running, I'll probably be looking for some type of American style diesel to run on them, and the Bowser unit is high on my list of possibilities. Another possible candidate is Bachmann's DCC HO scale GE 70 ton switcher which already has been converted in an RMC article to run on HOn3 track, so it should be easy enough to make it work on TT track which is wider than HOn3 track by about 1.5mm.

Regards,
Bill
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Re: Producing a new US style loco in TT scale

Postby scaro » Tue Mar 29, 2011 5:37 pm

What Elmer said was Bowser had a power truck for their trolley that 'may be able to be used' and he said he'd been to the firm an that they'd sell their parts to anyone. He observed that if you take the spacers out of the truck axles, they come in enough that they can be used for TT scale. He put the project on hold though so didn't take it through to getting a truck done. Someone else also said that 'it needed a smaller motor to work properly on 12mm gauge'. But it looks to me as though the motor is not in the truck itself, which is something I misunderstood from that comment. In any event, if the swivel possible on the truck is limited by the width of the gear towers and is not enough for a hood unit, it may have limited use.


One thing I did have a look at tonight was the measurements of a few N locos which might be candidates. Graham Farish (Bachmann UK) do this in N which scales to 9'3" or 9'4" wheelbase and actually has 3'4" wheels:

http://www.modelrailforum.com/forums/in ... topic=5392

Now what makes this interesting is the fact it is an outside frame loco ... the axles extend through the frames and out to the crankshafts. This may mean it can be regauged to 12mm. Note I say may, I only have one and I'm not game to pull it to bits.

Another candidate for a chassis - the Atlas N C628 / C630. A true N scale C628 /C630 would, near as i can calculate, be spot on for a TT scale GP7 in distance between truck centres, and would have 8'10" wheelbase trucks. I don't own one to measure the model itself, or to pull apart to see what potential it has, but the idea of just adding new, bigger wheels and a couple of shapeways-style truck sideframe spacers and adjusting the pickups for the wider gauge appeals to me. not RTR, but maybe simple enough that folk won't mind doing it ... and Atlas mechs are state of the art (though the mods to TT-ise it would surely void Atlas's warranty :wink: The thing with this is that all those split frame Atlas and Kato mechs cover a hell of a lot of different wheelbases, and trucks can be swapped from one to the other, reversed, all sorts of things.

Ben
Last edited by scaro on Tue Mar 29, 2011 8:07 pm, edited 2 times in total.
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Re: Producing a new US style loco in TT scale

Postby railtwister » Tue Mar 29, 2011 7:03 pm

Hi Ben,

Another possibility I just thought of, is the HOn3 version of the PCC streetcar advertised by Con-Cor, which was scheduled to be released in the Spring of 2010 (I don't know if they made that deadline or not). It is more expensive than the Bowser unit at $159.95, but it is advertised as being ALL wheel drive, whereas the Bowser only had one truck powered (4 wheels). If it is available in HOn3, the trucks would have to have their gauge WIDENED in order to fit onto TT gauge tracks, and this could be easier or more difficult, depending on the design of the drive. It might possibly be an underfloor drive, so it might even be a possibility for TT hood units. I've never seen one of these ConCor units, so I can't say for sure, but I think if the Bowser unit could be made to work for TT, the supply might be more reliable, since Bowser has a long history of good parts support.

Regards,
Bill


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ConCor HOn3 PCC trolley ad
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Re: Producing a new US style loco in TT scale

Postby sd80mac » Tue Mar 29, 2011 7:09 pm

I'm in agreement with you here. The only sourcing of existing models I'm going to do is to take their measurements and reduce them to TT scale. Kato and Atlas have some of the smoothest running trucks available in HO scale. Could we not benefit from them being reduced for use with TT?

Second, I do like the split frame idea that is utilized in N-scale locomotive design, and think it would be equally beneficial specifically in the area of weight. Now, what one could do is design the split chassis to use existing N-scale drop-in decoders which may simplify DCC conversion, although the lighting may have to be modified to fit the larger locomotive.

Donnell

ConducTTor wrote:As far as trucks and chassis go, sourcing from existing models (European) is simply not an option. Period. If anything is going to be made in any substantial numbers (read: more than 1) the manufacturers are useless because they don't want their parts in others' models. Having to buy an already existing model just to use for parts is not a proposition I like - if someone wants to do a run of 20 locomotives, they have to first buy 20 locomotives?

The U boat will be a huge jump forward for me as far as being able to offer other models. Once the kinks are worked out, variations of trucks / chassis should be very easy to make for use in other models.
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Re: Producing a new US style loco in TT scale

Postby sd80mac » Tue Apr 05, 2011 2:02 pm

Addendum:

Hello Modelers,

I do agree with railtwister that a smooth running chassis is essential, especially now at the onset of US-TT renaissance. Also, if you can show people that TT trains can run as smoothly as the lastest Kato, Atlas, Genesis, LifeLike, and offering of other noted manufactures, they may be more apt to take a closer, more serious look at TT scale.

Now, after further research (and a lot of tial and error), I found (and I'm sure some of you are more than aware) that NWSL makes 72DP gears and worms. Their smallest usable 72DP spur gear has 15T. I have designed an axle gear to match. It also has 15 teeth, and is shaped similar to the ones made by Athearn. A 15T axle gear will give us a 15:1 gear ratio, which is comparable to what's is available in HO and N-scale today. The one problem I foresee is price. Gears from NWSL are $5 a piece, and I'm not sure if this is the price per gear or for some quantity greater than one. However, I'm thinking that if I can buy them in bulk I can get a better price. It's either that or produce my own gears, with may not cost as much as I think.

Anyhow, the motors I'd like to use are also from NWSL, along with many of their other drive components, i.e. universals, etc. Again, if pricing becomes and issue, well, I may have to produce thoughs as well. As mentioned earlier, I think the split-frame is the way to go, but designing a more conventional frame/chassis/drive may prove useful for comparison.

Donnell
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Re: Producing a new US style loco in TT scale

Postby dileTTante » Tue Apr 05, 2011 4:13 pm

areibel wrote:
The Lok N Roll trucks are their own design,

They aren't their design. These are H0m tram trucks. I believe they are from Halling.

Forgive my ignorance, but I wonder why HOm drives aren't pursued? Bemo for example make several HOm locomotives, and Eurorail Hobbies here in BC Canada list Bemo spare part --

Bm1262000 Hge 4/4 II Rebuild Set w/5-Pole motor (No photo)

And Leopold Halling offers to make drives for manufacturers and have a PDF showing dimensions of their typical units. http://www.halling.at/index0.htm
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Re: Producing a new US style loco in TT scale

Postby scaro » Tue Apr 05, 2011 5:02 pm

the bemo is $150 and there's not even a picture so i imagine it'd be a brave person to order one. even so, BEMO are very pricey, so even if it worked, that might rule it out due to exchange rates.

the halling drives i can see there all look to have a minimum width of 18mm. a GP7 has a 6' wide hood, ie 15.24mm in TT.

however, it should not be beyond the wit of man, etc, lots of these bespoke things are done even in N. we just need someone who'll do 12mm. maybe this guy?

http://www.n-driveproductions.com/

note the outside frame shunter (switcher) chassis. useful, because with those longer axles it may well be possible to pull the wheels out to 12mm gauge. he uses 8.5 mm wheels which are right for a 40" loco wheel and with those two adjustments and the middle axle removed, this thing could be a motor bogie for a GP or U boat - the wheelbase is probably 23mm as the real thing is 11'6" in British N so probably 2mm/ft scale. might email him.

ben
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