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Varney Dockside Switcher

Started by jonathan, December 09, 2009, 05:14:48 AM

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jonathan

Some of the valve gear parts have started to arrive.

These are the parts from Bowser (what they had).  The links and rods from Bessemerhobby have not shown up, yet.  Hope they're legit.

Regards,

Jonathan

P.S.  Rather than pick a color, I'm polishing the hardware with 600 grit sandpaper.  Shiny is good...










pdlethbridge


Woody Elmore

Jon - I see that you've cranked up the old electron microscope again.  Just the addition of the crosshead guide hanger makes a big difference.

So did the PRR decals for the G-5 arrive from Lower Slobovia yet?

jonathan

#168
Yes,  those eye glass screws are straight pins with threads.  Need a bigger magnifying glass.

No decals, yet.  It seems some things are only made once a year.   Timing is everything...

Regards,

Jonathan

P.S. Don't know how this happened, but I have noticed I am forever waiting on parts to complete my projects.  I have too many irons in the fire. :)  


P.P.S  Don't want to move this thread up the chain for now.  However, the last of the valve gear parts have arrived.

I am in the throws of assembly and adjustments.  There are binds and troubles all over the place.  The main rods' holes are too small for the spacers.  The cross head guides do not want to stay in the holes in the steam chest.  I can't epoxy the guides or I won't be able to unassemble when necessary.  The left crosshead needs filing to slide smoothly on the guides.  I am glad I got 00-90 nuts to hold the eye glass screws (and some loctite).  Those little screws want to loosen at every opportunity.

To say the parts are small is an understatement.  I can barely focus on the parts, let alone work with them.  I feel I am one wrong turn from having the whole thing fall apart on me.

At least the riveting went well.

Hopefully the frustrating part won't last forever.  Wish me luck.

J

Woody Elmore

Jon: Wow! I cannot believe that the locomotive in the picture is the same engine I got off Ebay. 

Getting parts has always been a problem especially when the vendor is a small operation and the part is something really odd ball or rare.

In the real world my neighbor's Mazda had a door chime problem and it took the dealer 6 weeks to get the new part.


jonathan

#170
Right Side assembled:



It was not fun.  Right now I'm keeping my eyes on the prize (finishing).

Questions:

Will running the mechanism on the bench loosen it up?  I believe I have found and removed the binds.  However, it turns a little tight.  Don't know how else to describe it.  I'm thinking I can put the frame on a stand, hook up some leads, and just let it run until it gets loose, thereby burnishing and wearing the metal parts just a bit. Am I crazy?  Seems like a good idea at the moment.

Also, is the crosshead link suppose to be tightened in order to keep it parallel to the ground?  I really wish this stuff came with instructions.  An old picture just doesn't cut it.

Regards,

Jonathan

P.S. We're getting close to the end.  

J3a-614

It's looking good. . .

The stiffness you mention might be coming from one or both of two sources.

One would be that you might have made the rivets too tight.  There is something of an art to valve gear rivets, getting them just right, but it can take some practice, and it wouldn't surprise me that not all rivets and valve gear parts are created equal.  Check the swing of your riveted connections with your fingers; if anything feels tight to the touch, you can either cut and replace the rivet, or you might be able to very carefully stretch it by prying with a thin screwdriver. I don't have to tell you it's delicate, but it's doable.

The other possible source of tightness could be the crossheads and possibly the piston rods.  Your crosshead guides are now held in true parallel by the valve gear hangers as opposed to opening up a little at the rear, so the crossheads may be working harder against the guides; that you are now using cast crossheads could also be a factor, with the slots that run on the guides being slightly undersized.  Check this with finger motion again, with the cylinder block out of the engine; some very careful and slow file work can cure this.  Just take your time, be patient, and test your fit fairly often.  Also, see if the piston rod is tight where it goes into the cylinder block; the rod may be a bit oversized, or you may have a dab of paint in the hole that's causing interference.  Some gentle drilling to slightly enlarge the hole may do the trick.

Your angles for the crosshead link look fine to me.  This part does move, and you can see this if you look up the "Pacific 231" video clip, in particular as the engine gets under way at about 03:10 or so.

Oh, and I like how you managed to fabricate those tiny hooks and brackets for hanging the towing chains on the cylinders.  Neat!

NMWTRR

First comment fantastic job on installing all of the linkage.

I think JA-614 is right on the money about gently checking where it is tight as you rotate around, try and identify where it is tight.

If you choose to run it in you might want to do it slowly, would not want something to come loose and tear it up.

Your work is inspiring it is making a slightly old timer like me want to pull out some of those older mantua locos and see if they can be brought back to life!

Keep up the great work.

pdlethbridge

A trick the old timers used when  attaching rivets was to put a piece of paper on the rivet between the pieces to be attached to act as a gauge to tell when you are tight. pulling the paper out gave the right distance and looseness.

Doneldon

jonathon -

Looking good!

Trying to run the valve gear in is worth a try.  Keep the speeds moderate and change both speed and direction from time to time.  You could also try a teensie bit of graphite on the articulating rivets and the crosshead guides.
                                                                                    -- D


.

pdlethbridge


jonathan

#176
First,  thanks-a-million for the kind comments and helpful advice!

I have gone through and checked all the rivets. They seem loose enough.  I have the right and left side valve gears connected at the moment. Actually, the valve gear portion seems to be working quite smoothly.

I am down to one mysterious bind.  I find that when I loosen the steam chest (held on by nut and bolt for now), I can temporarily relieve the bind. Tighten the bolt, and the bind is back. There is a possibility that the piston rods are too long and bumping the inside of the steam chest.  I initially clipped about a 1/16" piece off the piston rods. It may not have been enough. Much as I hate to dismantle the whole thing again, I may have to. Trial and error will prevail, hopefully before I strip a screw or crank pin hole.

The hooks for the tow chain are lift rings for diesels.  I gently pried them open to get a hook shape. Then I drilled #79 holes and epoxied them in place. Will paint them (and touch up everything else) when the mechanism is finally working properly.  I have some blackened copper chain to hang as well.

Thanks again.

Regards,

Jonathan

P.S.  After further manipulation, bind is definitely on the left.  90% sure is the piston rod bumping the inside of the steam chest.  Must disassemble the mechanism and clip a little more off the rod.  The engine building bug is definitely being exercised from my system. :)  J

Johnson Bar Jeff

Quote from: jonathan on June 16, 2010, 07:05:54 AM
The engine building bug is definitely being exercised from my system. :)  J

But you will have a real gem of an engine when the project is completed.  :)

Woody Elmore

Jon - with what you have learned, the next steamer will be a breeze (ha ha.) You think the optical screws are tiny? Try some of those tiny metric jobs they use on the brass engines - they are really miniscule.

I suggest you run the engine on the bench upside down. That often helps in spotting binds. By adding the valve gear hanger you have taken some slop out of the mechanism and that will result in binds.

You need to be given an award for perserverance - of course you vision may never be the same.


jonathan

#179
Testing the mechanism .  Drilled a hole in my homemade paint stand.  Ran the assembly bolt down through the steam chest and into the hole.

It would be too long a list to describe all the manipulations I went through to free up all the binds.  The biggest one was indeed the left piston rod being too long.  Clipped another 1/16" off the rod.  Done.

I made a video showing how smoothly it was running, but the camera wouldn't focus on the frame (too blurry).  Here's a pic, running at about 25%.  Turned it up to 40% and cleaned the brass wheels.  Total run time was 30 minutes for the first test.



The hard part is finally done.  Phew!

Regards,

Jonathan

P.S.  Per Woody's tip, I held the frame upside down while it was running, then put it back on the stand. ;D  Why do these things always run better upsidedown and in reverse, but never running forward (normal running)? ???

P.P.S.  I put loctite on all the little screws so the thing wouldn't come apart on me during operations.