Bettendorf truck

[Devon_Sinsley]

Quick couple of questions. i want to make a printed Bettendorf truck for my fleet of log cars. I have plenty of pictures of the prototype. I am not a huge fan of the stock Aristo (though they would work) and I downloaded a file from thingiverse but it is being problematic. I want to reverse engineer a decent facsimile of the prototype. I am not at home nor near a g scale truck.

I need two critical dimensions. I need the “standard” spacing of the insides of the side frames so I know how wide to make the trucks to fit our wheels. and second what is a good spacing between axle holes so that our wheel easily clear the bolster?

If anyone could measure those for me I would be appreciative.

[Steve_GScale]

MTH Daylight Pullman, 1:32 one scale:

2.2155"

2.75"

Bachmann 92421 Metal Wheel:

2.127" (hub face to hub face)

[Devon_Sinsley]

Perfect exactly what I needed. thanks

That gives me enough to go on.

[Steve_GScale]

So I’m just learning about G scale trucks. As I understand it G scale track has the same dimensions regardless of whether you are using 1:22 or 1:35, or anything between. Rolling stock will use different wheel diameters and wheel spacing according to scale and prototype. I believe that different brands will also use different mount pivot geometry. I’m still undecided as to whether I am going to print my trucks or buy them. My current design will use a flat piece of ABS sheet stock for the car base, with the truck pivot mount (what is the proper term for this part?) printed and designed such that it bolts to the car (sheet stock) bottom. This way I can pair pivot mounts to trucks, keeping the coupler/car heights correct regardless of the wheel diameter or truck brand.

Anyone care to summarize the different possible mount schemes by brand?

[Gary_Armitstead]

Devon,
Why would you use Bettendorf trucks on log cars? Are these standard gauge log cars (skeleton or dis-connects? Usually these were NG (IMHO).

[Devon_Sinsley]

Gary,

this are not what your thinking when you are thinking NG old school skeleton log cars with archbars. Not sure when these cars were made but they were shop built converted flat cars that had the decks stripped and log bunks put on them. As such they were using transition era Bettendorfs with friction bearings as opposed to roller bearing.

[Devon_Sinsley]

@Steve_GScale

Anyone care to summarize the different possible mount schemes by brand?

I can’t because as you have noticed they are all different. What I do on scratch built cars is use a piece of nylon stock that is drilled and tapped for a #4 screw. I get these from my local Ace hardware. The O.D. I don’t remember off the top of my head but they are in any case just slightly larger than the average truck I have encounters. I drill a hole in my body bolster and epoxy the nylon in the hole. Epoxy only marginally holds nylon. So I score and scratch the heck out of the outside surface so that it has some tooth for the epoxy. I drill a hole in the truck bolster to fit the nylon. Before epoxying it, I insert it in the hole and put my truck on to get a length. I then cut the nylon to the right length. For a clean look i then put epoxy on the outer surface of the nylon and insert the cut end into the hole leaving a nice finished end protruding from the bolster. Don’t get crazy with the epoxy or it will squish up into the hole and make it hard to thread in the screw. Not a unfixable thing if it happens the screw often times will cut its new threads if not a tap will. I then use a pan head machine screw with a allan wrench hole and a washer to mount the trucks. I cut the “post” a little short so that I can adjust the tension on the truck with the washer so It has just a little bit of wobble to help equalize the car.

[Devon_Sinsley]

Here is the side frame so far

Keep in mind I am in no way trying to make an exact rivet counting model of any particular Bettendorf. I am roughly making a decent facsimile that looks something like the stock Aristos.

My goal with these is to actually make the entire truck as one piece hoping I can insert the wheel sets with a little gentle persuasion. I have little to no faith this will work. If not then I will make it in three pieces. I will design it in three pieces from the start and that way I won’t have to go backward should I decide I can’t make it in one go.

[Devon_Sinsley]

I have to say I am actually reinventing the wheel somewhat. Dan H has a design already that would more than suffice for what I am trying to do. I actually have some of his trucks he printed with filament before he got his resin printer. They are a solid design and if I were smart I would just ask him for it instead of designing my own. But that’s not how I work. If there are ten ways to do something I will find the hardest

[Jim_Rowson]

Hmmm. And here I thought you had created a topic where we could all post our 3D designs so we didn’t have to recreate them.

Weird!

[Steve_GScale]

@Jim_Rowson

Hmmm. And here I thought you had created a topic where we could all post our 3D designs so we didn’t have to recreate them.

I’ve been pondering that thought myself. I’ve got a LOT of balls in the air right now, but I will try to commit a design for MTH style truck mounts in the next few days. Question - is this the correct location or should a new thread be started?

[Jim_Rowson]

Devon had created this topic as a spot to share 3D designs. Hasn’t gotten much traction yet.

[Steve_GScale]

The rules: each maker should have only one post in the thread with a “catalog” of their offerings. They can add and delete by editing their post. You can upload .stl or preferably you should compress them (.zip) and upload that way for less storage and faster transfers. A small picture would be nice but keep them small, “catalog” style.

I’m not sure what I want to happen would fit there. This new thread should allow discussion of ideas, asking of questions, etc.

[Devon_Sinsley]

@Jim_Rowson

Devon had created this topic as a spot to share 3D designs. Hasn’t gotten much traction yet.

Yes i did create it, and no it hasn’t gained much traction has it. I make this vow that if this truck comes out nice and prints well I will add it to my list.

Here is the first complete version of the truck. I will use ball point pen springs for the springs as I think they look better than trying to print them and I don’t care one bit if they are a working truck the springs are for show.

Also i will make the axle holes larger once I figure out what bearing I am going to use and know its OD.

[Devon_Sinsley]

@Steve_GScale

I’m not sure what I want to happen would fit there. This new thread should allow discussion of ideas, asking of questions, etc.

Steve I think you are cross posting with Jim. I don’t think Jim was telling you to start your thread there. I think he was talking to me suggesting that Dan H put the design I was referring to there so I could use it from there.

As to your question you probably should create a new thread so that discusion on your topic can take place there instead of here.

[Devon_Sinsley]

Decided to make these in three pieces from the start. I had serious reservations about doing it in one so just bagged the idea. I added indexing holes to the tops of the frames so they can be drilled out for screws.

[Bruce_Chandler]

I really liked the way that the AMS trucks were mounted on their models, so I came up with something similar:
From McMaster-Carr I got Compression Spring, 0.12" OD, 0.08" ID (I typically cut them to the length I needed) and some shoulder screws. I tapped the frame to attach them to the bottom and slipped a piece of spring over it. Anyway, you can see a bunch of pictures here: http://jbrr.com/rolling-stock/buildlogs/4hoppers.html!
And the pictures work now!
I used a small acrylic square sandwiched between some I beams.

This shows the 4 frames under construction (only the 2nd one is right side up!)

[Cliff_Jennings]

You’re really blasting through cad models now Devon, great work!
Was it not quite a year ago that you started learning the (Fusion?) software?

[Devon_Sinsley]

About a year. I have a huge thank you to Dan H for all of his help walking me through it. And he said once it clicks it clicks and it becomes fairly easy. I think I have a good grasp of it now. Every so often I can’t make it so something I want it to do but for the most part I can pretty well rip through a design.

[PeterT]

[Quote]what is the proper term for this part?)
[/quote]
Steve, it’s called the bolster.