Stretch Husky in a weekend

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senorgilamonster
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Stretch Husky in a weekend

Post by senorgilamonster »

Inspired by Harlock's flat car in a day (http://www.chaski.org/homemachinist/vie ... it=harlock), I'm going to try to build a little electric locomotive modeled after Eaton's Super Husky. I will be adding several inches to the length, hence the Stretch Husky. No reason other than my personal preference for the aesthetics. 1.6" scale.

How I got here: I had some old parts laying around that I thought I was going to recycle into my GE 50Ton. I am far enough along on that project that I realize the only parts I could re-use were a pair of rusty sprockets. I also had an Eaton Husky cab that has been in storage for a decade. I looked at the pile of parts and went....why not.

Not counted in the weekend, is the design (which is loosely based on the way the parts were originally assembled when I first got them a decade ago and the Eaton), and the gathering of the materials.

What might not get done is the hood. I bought the sheet metal but got 16ga and my little bender ain't gonna do it, so I either need to build a bigger bender or get 18ga instead. Either way, I'll lose 1/2 day on that alone. I don't have enough detail panels for the hood either, so that and some of the other detail parts may be missing.

I'll be taking pics, but daylight is burnin'.
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senorgilamonster
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Re: Stretch Husky in a weekend

Post by senorgilamonster »

1: How can I press the wheels onto the axles without a press? I'm thinking a hammer isn't the right approach.

2: Any suggestions for a paint scheme?
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Dick_Morris
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Re: Stretch Husky in a weekend

Post by Dick_Morris »

Answer #1. About .003" clearance and Loctite. (Verify the clearance from the Loctite specs.) Also consider using the correct Loctite primer for max strength.
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Harold_V
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Re: Stretch Husky in a weekend

Post by Harold_V »

senorgilamonster wrote: Fri Feb 09, 2018 7:27 pm 1: How can I press the wheels onto the axles without a press? I'm thinking a hammer isn't the right approach.
What Dick said, but if you prefer a metal to metal fit, you might consider shrink fitting. In this process you machine the components for a press fit, then heat the wheel and chill the axle. When done properly, the wheel will slip right on, then lock in place when temperatures equalize. It's a better method of assembling than press fitting, as it removes the off-chance that you'd get a wheel on crooked. It also grips better, as there's no abrasion in the assembly process.

Assembly must be quick and precise. If you tarry, there's a chance the two will seize before the axle is properly fitted. A little extra heat for the wheel and a simple setup that helps guide the axle to the wheel goes a long way towards eliminating the problem.

A hammer for a press fit should almost always be a last choice. There's far better ways to get things to go together.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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senorgilamonster
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Re: Stretch Husky in a weekend

Post by senorgilamonster »

My hammer comment was a joke.

Thanks for the advice - I tend to overlook the obvious solution sometimes.

Progress was mixed yesterday. The only productive thing that got finished was grinding, scrapings, sanding, priming and painting the axles and old sprockets. I made an design change on the fly while cutting the frame. Bad idea. The whole thing wiggles like a bowl of Jello. So today I am re-engineering the frame, and cutting new metal. The biggest value out of the whole exercise is that I was able to precisely measure for coupler height and will adjust the frame accordingly. I took pics...but cannot get them off the phone yet (1 more thing that went wrong)

AT this point It will be weld together (and I haven't taught myself to weld yet), so I don't think I'll be taking it to a track on Tuesday...Unless I go to Burnaby B.C., join, and they teach me how to weld. :) My helmet arrives on Wednesday. Louvered doors for the hood arrive on Tuesday.

I did decide on a paint scheme - the same that I plan on putting on the GE 50T. That way I can see if I like it, etc. As it turns out I am glad that I am doing this project since I am making mistakes building it and not on the bigger, more complicated beast.
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Harold_V
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Re: Stretch Husky in a weekend

Post by Harold_V »

senorgilamonster wrote: Sat Feb 10, 2018 12:00 pm My hammer comment was a joke.
I know that, and I suspect most readers know that, but there may be some unsuspecting person who doesn't know it---which is why I commented as I did. One must keep in mind that we have readers with a keen interest, but who may not be mechanically adept--and may benefit from fundamental guidance.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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senorgilamonster
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Re: Stretch Husky in a weekend

Post by senorgilamonster »

good point. Actually, I am one of those not mechanically adept.
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senorgilamonster
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Re: Stretch Husky in a weekend

Post by senorgilamonster »

First I laid out the parts that I had collected. I found I was missing a stainless steel bolt and one of the bronze bushing/bearings. SO, back into town for hardware right out of the chute. I couldn't find a matching piece of bronze, so I got the next closest thing and will have to do some cutting.
stretch build 1.jpg
Next I located the 1.5 x 3" and temporarily attached it to the deck by four self tapping screws. I took this approach so that I could ensure everything was aligned and running before committing to a weld. (good thing too) The size was chosen to give sufficient height for the coupler.
strecth build 2.jpg
the fatal flaw was that I decided I didn't want the bolts protruding through the deck, so I dropped them so that the bolt heads were inside of the rectangular tube. Unfortunately this doesn't give the bolt any stability and the result was that the bearing blocks freely wobbled in all axis.
stretch build 3.jpg
Now some will say that I was cheating on the time since the cab was already assembled. BUT the axles and sprockets were rusted. I had to spend quite a while scraping and sanding the rust off before I could prime and paint them. So I figured it was an even trade. I decided that I am going to attache the super structure to the top of the deck using a series of magnetic cabinet latches (circled). I'll epoxy these to the inside of the cab and hood. Need the hood off - just give a mighty upward pull, no tools required. I'll put in a couple of locating pins though.
strecth build 4.jpg
I also bent the first of the 4 step brackets. I think this one is a bit too wide, so I'll bend 4 narrower ones. Since I had hit the wall on progress, I decided to prime and put down the base coats of paint on the cab.
strecth build 5.jpg
So - a fail for getting it done in a weekend. I have to cut a new frame, re-drill it and the deck, etc.
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senorgilamonster
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Re: Stretch Husky in a weekend

Post by senorgilamonster »

Didn't do anything for the last day and a half...but got in 7 hours today:

Disassembled the old frame, cut and drilled new frame pieces (better design anyway), and layed out the parts. Had to go into town for new, longer stainless steel bolts. Cleaned out the old bronze bearings and put new grease on them.
do over.jpg
I decided to build a jig for bending the step frames. While I don't think that 4 is enough for a jig, I want to use Nelson Riedel's method of bending arch bar truck frames, and thought this would be a good time to build a similar jig for the steps. Of course I spent more time on the jig than if I had just bent the frames in a vise. Nelson's page is here: http://www.nelsonslocomotive.com/Small% ... ckBars.htm
bending jig.jpg
After doing a test bend in the jig, I decided that I like the tighter radius achieved by hammering over in a vise. I do like the wider radius of the jig for the arch bar trucks though, and know how I will do a better job of building that jig (eventually).
bend comparison.jpg
bend comparison.jpg (16.9 KiB) Viewed 10024 times
Finally the sheet metal for the hood (and the cab for the 50 Tonner) arrived. I cut myself on the box. :( Funny, it doesn't look much like a locomotive:
doesnt look like a loco.jpg
rkcarguy
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Re: Stretch Husky in a weekend

Post by rkcarguy »

I have had good success bending flat and round bars in the vice, and even made some wooden jaws from a scrap piece of oak so the jaws don't mar the material. The brass ladder rungs on my S12 were formed in the vice, nothing more.
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senorgilamonster
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Re: Stretch Husky in a weekend

Post by senorgilamonster »

Crumby weather day in the Pacific NW means not a lot of work on the loco for me since I don't have a garage or shop. But with the arrival of sheet metal yesterday I decided to set up for bending the hood. I did a test bend with a 1/2" i.d. radius on 18 ga steel and it came out great.

Went to bend the hood - when I layed it out I discovered I had originally mis-measured when I placed the order and the metal sheet was too small. I think that I am done for today.

for those interested in how I bent the metal, I posted some pics on this thread: http://www.chaski.org/homemachinist/vie ... 3&t=106367
rkcarguy
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Re: Stretch Husky in a weekend

Post by rkcarguy »

The stretch out can certainly vary by material type and thickness, I will usually make my bends and then trim the long side afterwards because it almost never breaks "perfectly". Hopefully you can use your sheet in other places?
That's a cool post about using MDF, I failed to mention that I did run the router down one side of the oak scraps so I would get a radius on the rungs I made.
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