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Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Tue Apr 24, 2018 8:32 pm
by senorgilamonster
a few more pix

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Wed Apr 25, 2018 1:57 am
by rkcarguy
Looking good!

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Wed Apr 25, 2018 8:11 pm
by senorgilamonster
Welded up the coupler pockets today. They may be ugly, but you don't see them and I am not worried about a runaway train due to pocket failure.
pockets.jpg
I started working on the pilot today. While the SP1 isn't a particularly graceful engine, I do love the baby pilot.
pilot1.jpg
Finally I welded in the center frame supports and fuel tank
frame.jpg

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Wed Apr 25, 2018 9:24 pm
by NP317
Thought:
Your welds look like they were a little cold.
Try increasing the current for better penetration, while concentrating on the thicker piece being welded.
I'm sure a real welder (I'm a hobby welder) can provide better advice.
~RN

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Wed Apr 25, 2018 10:02 pm
by steamin10
Ya, a typical beginner weld. Slow down to flatten it out/deeper pen. Up the current, keep the arc short. The thinner the metal, the faster you have to run to keep from melting through.
All these things are a balance of what you see, for eye/hand co ordination. One of the best ways to learn, is to get some scraps of what you are working on, and do some test beads right before you strike an arc on your needed part. It gives you the opportunity to sharpen your 5 minute skill, before you melt your finished part.

When in doubt, toss it out. If you build one, you can make another, and the learning curve continues. I have welded frames together for cars and the one that was done last is always better than the first. Thats what flap wheels and 4 inch grinders are for, dressing up chicken poo welds. The frustration subsides when you improve, trust me. I have ground many a weld to put more metal in its place, we all start somewhere.

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Thu Apr 26, 2018 11:27 am
by rkcarguy
Sometimes these little hobby welders don't really have enough power. I know a friend of mine would sit parts on his propane BBQ to preheat them, and would get a much better weld. Grinding away the mill scale near the weld, and even grinding a "V" at a butt weld joint can provide much better results as well.

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Thu Apr 26, 2018 8:38 pm
by senorgilamonster
Thanks for all the helpful comments. I had the settings for welding thinner stock and was going about the speed I needed to keep from burning through MOST of the time...I failed to crank up the power and/or slow down when I went to the thicker stock. I slowed it down today...and even got my first decent looking fillet (for about 3/4").

I went ahead with the suggested bolster set up. It added 2 days work time and about $70, but I am sure it will be worth it in the end.

I put in the first coupler pocket today...it is actually starting to look like something:
frame2.jpg
Since it upside down on the sawhorses, I flipped the pic

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Thu Apr 26, 2018 11:34 pm
by senorgilamonster
after this pic I added a 1/8" plate to extend the surface that the roller bearings on to allow for a tighter turning radius. After final assembly the bolt will be cut down. I got a longer bolt than necessary so that the bearing ID would be on the shoulder and not the threads.

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Fri Apr 27, 2018 10:22 am
by rkcarguy
Looking good! It would suck to get into a tight curve and have the locomotive tip over because the bearings ran off the plate lol, so good thought extending those.
I work in management for a steel shop, it's regular practice and often a requirement to have no threads in the shear plane. As such, a structural bolt may give you the shoulder you need without having to cut off a bunch of extra.
Another tip for welding, my friend who is a professional welder, put pieces of masking tape on his welder with the different settings written on them that worked good for different thicknesses of metal and position, if not a flat weld.
Also, you can run a very hot setting when tacking everything in position, and then turn down the power and go back and weld everything out. In addition, I have used the tack setting for making welds, and basically just do a row of hot tacks in a row with a pause in between so you don't burn through. You look for the tack to just wet out over the center of the prior tack then pause and move forward. This works well when you have a short weld securing a small part and need good penetration from the start, where if you ran a continuous weld the small part might get too hot and burn through. Get it down, and you get a nice stack of dimes:)

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Fri Apr 27, 2018 1:46 pm
by cbrew
one thing to note. unless you are riding the locomotive itself, I have found side bearings are not needed.
both of these dismals track great, I mine as never been on the ground
just a thought.
happy building
dismals.jpg
truckmount.jpg
truckmount1.jpg
truckmount2.jpg

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Fri Apr 27, 2018 7:32 pm
by senorgilamonster
I continued working out the details for the pilot. Here is a test build of the pilot made with hand tools. The hole angles were eyeballed Actually, I was surprised at how well it went. The bottom plate goes to the trash now but I worked out how to drill the holes at an angle.

I decided to drill the new bottom plate before cutting it to shape so that I can more precisely control the amount of meat left at the front edge. The new holes will be done with the drill press so that I can control the angle better.

Re: SP NG Diesel #1 (GE 50T) - Triennial or Bust

Posted: Sun Apr 29, 2018 9:58 am
by senorgilamonster
I drilled and tapped the holes for the strap that limits the pillow block travel (preventing it from falling out of the bottom of the truck) in one sideframe. Continued working on the pilot.

I was at my local Tractor Supply when I saw these repair parts for a John Deere. They looked like 2/3 of a 3 lens classification light. I measured them and they scaled out to the right size for the front of my loco. I have more confidence in my ability to add the front lens piece(s) than I do to machine one from scratch and it would be way less work than to design and cast my own. For better visualization I took a photo of the MDF front pattern and test headlight lens with the pieces. I overlayed this pic with a photo of the protoype - yup they are almost perfect.
Markers.jpg
I've not been too happy with all of the axles that I have turned to date. Each one has a single flaw of some sort or another. I decided to crank up the lathe again and see if I can up the quality of a couple of the axles. This one (1/2 done now) is perhaps the most accurate one I've done to date. Now if I can just do the other side to the same quality...
Axle.jpg