9 Foot Power Truck

Re: 9 Foot Power Truck

Postby Marquette » Wed Apr 30, 2014 11:11 pm

Possibly a bit off topic here, but I saw in another thread re the GP-9 chassis... do you have those available?
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Re: 9 Foot Power Truck

Postby Rob M » Wed Apr 30, 2014 11:25 pm

For the GP-9 you need to send me your chassis (or complete loco*) so I can machine the truck pivots and motor mounting hole.

For the F3 I make my own chassis so I don't need the loco to make them up but I do have a few RTR ones available on my site.


*For the GP's it is probably best to ship them to me in their original tin since it cradles them so nicely. The hand rails on them are pretty fragile.
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Re: 9 Foot Power Truck

Postby Shipsure » Thu May 01, 2014 12:33 pm

I'm new to this discussion and new to TT scale. Looks like my cup of tea. :) Have you all considered the NWSL Flea for a power unit? I was noodling around with the HON3 version and I think that can be gauged down to work on TT track. I'm not new to loco design, I'm the Design Engineer at Micro-Trains and worked on all the Z Mechanisms and now some N scale units and I would bet that using RP or SLA to make a case and a combination of Off the Shelf Gears that are available we could make powered trucks, or trucks with off set centers that allow for re positioning. I know that Shapeways now offers RP metal prints that would give you case integrity and allow for bushings to be installed for the axles for smooth running. The main deck could be laser cut (I've done this for trolley models) with the opening to allow a pivot and swing and you can us it for anything really. NWSL makes a number of different wheel sizes that can be used. Again, excuse me if this has been discussed before, just adding an observation. Interested in some feed back, I could scratch up a design and some gear options. What leads me to this was the discussion on the brass SD 45 (amazing work by the way) and my thoughts on doing a couple of Alco C 415's in SP in TT Scale using a home grown modular power system. I also have access to Maxon 8mm coreless motors we use in our Z Gp's and thinking that may fit in-between the wheel sets as they do in prototypes.

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Re: 9 Foot Power Truck

Postby richardedmonds » Thu May 01, 2014 4:00 pm

Welcome aboard Shipsure you might be just the man I need. Diesel mechanics and small gears is not my thing but your skills will be a big bonus
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Re: 9 Foot Power Truck

Postby areibel » Thu May 01, 2014 6:35 pm

The Flea could be used for a cab unit, but it's too fat for a hood unit. The problem in TT (usually)isn't getting the wheels in gauge, but getting a motor or gear tower that can swivel enough inside a hood unit to allow a normal radius. For example, the resin GP38-2 shell has a width inside of 13mm (.512), but the motor of a Flea is .497, not much room to maneuver. The Lionel GP9 is even tighter, about .485 so it doesn't look like it would even fit.
Luckily there are options available, from Lok N Roll and Hollywood Foundry, to the work being done by Rob and Bernd (check their threads), it's getting better and better!
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Re: 9 Foot Power Truck

Postby Shipsure » Thu May 01, 2014 7:20 pm

One thought I had was mounting bipolar 3vlt pager motors between the wheels like powered axles with a plastic gimbal that they snap into. Each wheel set is powered by a motor. 2 of those in each truck equals a lot of tractive force and makes the truck a simpler proposition. Our 8mm motors without the flywheels are just about right for the width, I'll check tomorrow. Those are amazing little units. I may also have some of the small can motors that are produced to upgrade Z scale Marklin steam locomotives. I converted a few of my NN3 MTL Mogules with them and they run great. I think I paid $8.00 each from a fellow in England. Those will fit between the wheels too. Just noodling.

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Re: 9 Foot Power Truck

Postby areibel » Thu May 01, 2014 8:41 pm

Interesting concept! I'd heard of plans to do something similar in HO, but that was the whole Railflyer/Chris Howard thing that crashed and burned badly.
One criticism I'd heard about using the pager motors is they're not manufactured to tight enough tolerances that if you have four or six under a locomotive they wouldn't all be speed matched- You might get three out of four running at the same speed but the fourth would be running 10 or 15% faster or slower. Or each would be running at a slightly different speed, since for the application they were designed for the speed tolerance wasn't critical. Now I'll admit that came from a person that is not a fan of Mr. Howard, do you have any experience that this is or isn't true?
But if it did work- what a possibility! Even a Shapeways produced mount would do, just clip them in, wire them up and go!
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Re: 9 Foot Power Truck

Postby Shipsure » Fri May 02, 2014 12:07 am

areibel wrote:Interesting concept! I'd heard of plans to do something similar in HO, but that was the whole Railflyer/Chris Howard thing that crashed and burned badly.
One criticism I'd heard about using the pager motors is they're not manufactured to tight enough tolerances that if you have four or six under a locomotive they wouldn't all be speed matched- You might get three out of four running at the same speed but the fourth would be running 10 or 15% faster or slower. Or each would be running at a slightly different speed, since for the application they were designed for the speed tolerance wasn't critical. Now I'll admit that came from a person that is not a fan of Mr. Howard, do you have any experience that this is or isn't true?
But if it did work- what a possibility! Even a Shapeways produced mount would do, just clip them in, wire them up and go!


It's easy enough to put resistors in line to regulate the speeds...even a potentiometer would work to get things lined up properly. Generally though, you have the same issue when you MU two engines together and you are not using DCC. If you are within 10% or so you may not have a problem other than some extra drag. Not the best situation, but you can control the level of current for the motors easily. You would also need a small board to keep you from exceeding voltage limits, but those can be cobbled together. Also I've come a cross some high end pager style motors that are rated at 6volts and used in timing situations, those would be the best. Like I noted before, you can get RP parts done in metal from Shapeways. Bryan Bussey did some testing with the materials for one of his N scale projects. If you can get ahold of any of the old 2mm Gauge magazines from the 1960's from the UK, there are plenty of nifty solutions for making powered chassis including belt driven units or pan motors. Back then 2mm was about where 3mm is today with ready to run motive power. I have some bound editions and see if I can clip and share some of the articles. Stone age stuff but it was bullet proof.

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Re: 9 Foot Power Truck

Postby Shipsure » Fri May 02, 2014 12:30 am

Thanks Bernd, great work there. You know, one of the advantages of using belt drive is if you position over the pivot point or near it you can mount the motor above the Gimble or gear tower in a stable position and have the truck rotate below it. Given the limited angle it has to travel, the belt drive would not have to stretch, it would move towards a slight figure 8 in that position and probably not see any deflection or speed loss. I have some very old N scale loco's with this system and the tension on a rubber band drive is enough to allow give. Here is an old Lionel drawing of a proven drive system that would be easy to build with off the shelf components. Find an old Athearn blue box ho engine and scrap the truck for gears and such. Image Even easier...Image Image Ive seen these drives at swap meets for $5.00 or given away. I do a lot of HO and love the old metal kits and locos just for the components they yield. Another great place to get belt and drive components are out of old printers, scanners and fax machines. You will be amazed at all the stuff you can cull from then to use in animation projects. I worked with Disney Imagineering for 20 years and if it moved or made a sound it was scrapped for it's components and considering how disposable those are, you are never out of fun stuff to animate. One last thing, some of the coolest drive mechs I've seen used high end machine bolts cut to length, hollowed out to accept the wheel axle and a brass deck screw cut, hollowed out for a drive shaft and used as a worm gear. It's so simple to do and if you run the parts in a drill and de-bur with emery or files, you can get a flawless drive in any number of combinations.

Second thought...In z scale we had similar issues with drive mech's and one of the things we did was to make the rear truck stationary...it didn't pivot and could have a large motor mounted to the frame with a direct drive. The front truck was on a pivot and not powered...in operation, it looks just fine and you can drop a huge 10mm coreless in there and pull bricks around the track.

Sorry for blather on here. Tons of great solutions out there, we just have to think out of the box. I try and mock up a chassis using rubber bands and see what kind of performance I get on the test bench.

Joe



Bernd wrote:
Shipsure wrote: I think I paid $8.00 each from a fellow in England. Those will fit between the wheels too. Just noodling.

Joe


Hi Joe,

Check out what Ken Rickman designed. Single Motor Truck Ken's thread on single motor drive axels using Nigel Lawton parts and NWSL parts. You may find it interesting.

That fellow in England isn't named Nigel Lawton is he?

Welcome aboard by the way.

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Re: 9 Foot Power Truck

Postby Shipsure » Fri May 02, 2014 12:40 am

Image This could be fabricated out of etched brass with some off the shelf pulley's

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