Solid vs. Built-up Frame

[GoldenSpike53]

Greetings all.

I have been considering making a solid frame for my Allen Consolidation instead of the built-up frame in the plans. The cost for the materials isn't that great (and I get a very good deal on it...) but there are a couple of questions that need asking.

First, in looking at the plans, it seems that I can easily make a solid frame starting at the rear, replacing the two castings that make up the rear of the frame, and moving forward to include the cylinder bars. The bottom of the built-up frame is a single piece, so the bottom of the new frame would move up half an inch so that pedestal binders could go on.

The frame also has two more castings, called front frame extensions, that go forward from the cylinder bars and carry the lead truck. They also have a tab on each that gets mounted to the cylinders. That would not be easy to fabricate into a solid frame, so I assume I should retain the front frame extensions. Does that sound reasonable?

Second, I have been talking to a builder in the area about using sealed bearings, but the original journal boxes are too small. So I was thinking that, by making a solid frame, I could also increase the distance between the pedestals and the height of the pedestals to accommodate a slightly larger journal box. But I was wondering if anyone has any experience with or feedback about using sealed bearings for locomotive drive wheels. Any thoughts?

Thanks for any feedback.

Dale Dennis

[liamlocomotive]

Hi Dale,

Personally, I use frames cut from 2 pieces of flat stock that are dowel pinned together. (The Brits do it in a similar way, but their frames are much thinner with castings to build up the surface thickness for driving boxes.)

For a 1 1/2" scale locomotive I wouldn't use anything thinner than 1/2" (X whatever the frame height finishes to) steel bar or a burnout from a piece of plate. Water jet cut frames would be ok, too. Not having seen your prints, I would say that you could use bar steel for your frames without too much trouble. Just make the appropriate cutouts and mke the cylinders a tight fit in the frame to minimize weak spots.

The full sized locomotive builders got away from the bolt together frames mainly because of the maintenance issues. Broken and loose bolts were the norm....As locomotives got more powerful, things really started breaking. When the N&W was building the Y-5 class 2-8-8-2's in the early 1930's; they were originally built using built up frames. The locomotives had more power than their predecessors and were in the shop almost as much as they were on the road. N&W then had General Steel Castings Company cast 20 frames to be used on those locomotives which solved the problem.

I'm not too keen on using sealed bearings where it's difficult to remove them. Besides the fact that you can't lubricate them. I like needle bearings for driver axles. You need to lubricate them prior to each run and at the end of each run.

Andy Pullen

[GoldenSpike53]

Thanks for your reply, Andy. I've been looking over my plans and scheming a bit. I made a drawing of the full frame profile, including the castings at both ends, and I think it's doable. For the tabs on the front castings, I should be able to create a cutout where the tab projects, then cut a piece of stock to fit in there and have it project out far enough to provide the face for the tab. Then I can take it to our welding shop and TIG the pieces together, hopefully without any serious distortion. I have an angle clamp to hold the pieces at 90 degrees.

I understand what you're saying about sealed bearings; I do know a couple of builders who are using them, anyway. I guess my main dissatisfaction with the bearings on my plans is that they are lubricated through holes drilled in the axle. Our club steamer has bearings with zerk fittings on them, and I would much prefer that kind of arrangement. Any thoughts on that?

I've also found that I can get the materials for the solid frame (.5 x 4.5 HRS bar stock) for a lot cheaper locally than online, so I'm going to pursue the local outlet. Fortunately, I can still use my alternative resources that get it for me without any out of pocket expense. (It's a work/trade situation for those with intense curiosity....) Too bad I can't get my castings the same way!

I think I will like the solid frame better, and hopefully can get it cut without too much difficulty. I know the jaws are the most critical part. Should be fun!

Dale

[Doug E]

Dale,

I think you will have a much better frame making them out of a solid bar of steel as you propose rather than building a frame up. It sounds like you will be able to get rid of all the frame castings, if I am understanding you correctly, which would be my choice in the matter, fwiw. Andy's comments are pretty much in line with my thinking.

Regards,

Doug E.

[liamlocomotive]

Thanks, Doug,

Hi Dale,

My locomotive uses the ball type oil hole covers in the ends of my axles. I had to drill a 1/16" dia. hole in the bearing race to get the oil through it. You will need a carbide drill for that. Personally, I use MA Ford "Hi Tuf" drills for that. I carefully stone the hole inside and out to debur it afterwards.

As to zerk fittings, use the small ones with a 1/4"-28 tapered thread on it. They won't be too noticable in the end of the axle, or anywhere else...You can get little dust covers to cover them, too, I think...

You shouldn't have too much trouble with warpage if you're tig welding things....Just don't try to weld the whole thing in one sitting to keep the heat down. It will still move some. That much heat will move anything, believe me. I've worked with alot of weldments over the years. You may have to rough things out, weld them and then finish machine. That's pretty much standard procedure in industry.

Good luck, and let me know if I can be of any more help....

Andy

[GoldenSpike53]

Hi, Andy.

Again, thanks for the comments. I know that the bearings that Gene Allen specs for this locomotive are designated with an -OH at the end, which, I am told by my friend who sells bearings, means "oil hole". I presume that such a hole should be big enough without having to drill another.

Our club locomotive has the zerk fittings on the axle boxes themselves, and is lubed from underneath while the locomotive is in the steaming bay. It may seem a tad awkward, but seems to work well. They also lube it with grease as opposed to oil.

I have seen a few people who oil the bearings through openings or holes drilled through the axle. On my drawings, it calls for a pretty small diameter hole, I think maybe 3/32, or maybe it was 1/32? Anyway, the only drill bits I've seen in that size are nowhere near long enough to drill a hole that small as deep as is shown on the drawings. Presumably, there are long versions of those bits available. Then another hole has to be drilled at a right angle to the axle hole; it has to intersect the axle hole and line up with the bearing.

I guess I just see a lot of trouble in creating that arrangement; drilling a precise right angle hole in round stock, and a 2-1/2 to 3" hole in the center of the axle, with a small drill bit that has a propensity to break rather easily. I guess I was hoping that the axle box lubing idea would avoid some of those complications....

Just trying to keep my options open. ;D

Dale

[liamlocomotive]

Hi Dale,

If you use the zerk fitting in the end of the axle; you will need to counterbore the hole to clear the installation tool for the fitting. You could certainly drill the hole to depth with the tapdrill which will in turn make a resevoir for your lubricant. The cross hole can then be drilled with whatever size you're comfortable with...

You could certainly use a grease fitting in the axlebox if you want. But, keep in mind that you may run somewhere with no steaming bays. Temporary tracks come to mind....Makes me glad I used the axles...

Andy

[GoldenSpike53]

Hi, Andy. I wasn't thinking of a zerk fitting in the end of the axle; only if I greased the axle box directly. Well, you've given me something else to think about. I don't know how much chance I'll get to go to other tracks, especially temporary ones. Our club does an annual run with temporary snap track at the International Rail Fair in Roseville, CA; in fact that's coming up in a couple of weeks! But they have an elevated section they built into the track to make off-loading easy, and I assume they could also use that for lubrication if need be, although I suspect they probably lube it in a steaming bay at the club track first before loading it up to haul it out there. Maybe some day, when my locomotive is finished, I'll get to run it out there with the club engine....

I also wanted to ask another question...you mentioned keeping the two pieces together with dowel pins. Would you not suggest using a bolt and nut? Would that give to much slop? I guess I was thinking maybe a couple of dowel pins on opposing corners to hold the pieces in alignment, and a few bolts and nuts to secure them together without having to use clamps.

Thanks.

Dale

[liamlocomotive]

Hi Dale,

I use dowel pins to hold my frames in the proper relation to each other. I ream the holes and use at least 3 pins. Bolts are not made to close enough tolerances for this kind of work. Dowel pins will allow you to take things apart to debur as needed. What is needed is for things not to move when doing the actual cutting and to go back together exactly the same way as they came apart.

I've used c clamps to hold pinned frames together for machining when hanging out of a vise or when clamped to the table...

Andy

[locodan5416]

It depends if you are trying to build a model locomotive or an amusement park ride.

I say build up the frame using socket head cap screws to keep everything together...the loads are so little that you can get away with it. also it is alot simpler, and if I was doing the frame as one piece, I would go with watercutting, and unless you can make a cad drawing, they probalby won't do it unless they charge you to draw the frame on the computer.