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Caspar Lumber "Trojan" Build Log

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bille1906

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Discussion starter · #1 ·
Caspar Lumber had two Mallet engines purchased 20 years apart. The later one was Samson which had the build log posted previously. The Trojan was the first one and differed from The Samson having slide valves and saturated steam.
Here is a photo of it working
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And here is a drawing showing most of the detail which I have produced in 1/20.3 scale.
This was a very small Mallet and doing it in 1/32 would in my opinion make it look too toy look.
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I start by making the cylinders in similar fashion to prior builds. Rather than using a cross port plate I made a similar plate with machining on both sides but with straight porting as shown in the upper plate.
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i must run now and will post more later.
 
Discussion starter · #3 ·
Thanks Russell
I was a little rushed on my last post and should have given a little more info on the Caspar Lumber operation.
The Caspar Lumber Company operated its own private railway which extended east from the Pacific 26 miles into the lush redwood forest area,125 miles north of San Francisco. It ran a vast array of locomotives but was best known for its two Mallets. It was also known for its massive timber trestles. The railway moved giant redwood logs as photographed bellow.
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Back to the build. My cylinders were bored out from square stock which was rounded over with 1/4 round roundover router bits. I use my router but these bits can be also used in a mill. The high pressure cylinder is bored out to 5/8" and the front low pressure one is 13/16". The boring is done on the lathe with a self centering four jaw chuck.
The valve plate is cut at 30 degrees to mate with the valve body which extends out from the side of the cylinders.
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The valve body has rounded edges. I use a 3/16" roundover bit mounted in the mill to do this.
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Here you can see the cylinder on the right has had the roundover treatment.
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And here are the four cylinders so far. I still have some work to do to them but the rough shape is done
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Discussion starter · #6 ·
I was wrong about running out of Ft. Bragg. It was the California Western RR that ran out of that area. See the map bellow
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Back to the build
Dennis cut out the frame rails from my CAD drawing and I made the crossmembers and assembled them
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The cylinder heads are turned from brass bar stick and the covers are turned from aluminum bar stock
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The valve bodys bolt on to the cylinders with four flat head stainless screws and the covers cover them up and are held on by the snifter which is threaded to 2-56. Below you can see the underside on the left
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The LP cylinder has a strange (to me) setup which I have tried to duplicate.
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#7 ·
Beautiful work Bill, and thanks for showing the forming of the outside curve of the cylinder with the router bit on the mill, sounds a lot safer than doing it on a woodworking router, with the cylinder bar stock firmly held in the milling vice.

I am glad I have gotten back to making rolling stock after two years moving and getting over an illness and two years building my pike and pointwork. I will post that in the rolling stock section. Keep up the great series on how to do it; very useful for those like me who don't have a model engeneering training.
 
Discussion starter · #8 ·
Thanks Simon
Here is a few photos of the side rods drive rods and axle blocks
The drive rods and axle blocks are fitted with M5 x 10 ball bearings and the side rods have a pinned slot and tongue connection
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The side rods are cut on the CNC mill by Dennis to my CAD drawings, On the mill, I cut the slot and tongue wit a 1/16" slitting saw. Note how two pieces of 1/8" material are used to clamp ihe rod between the ends
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1/4" 303 stainless is turned down to 1/8". The side rod is slipped on so that the E clip retainer will be flush with the rod.
The groove cutting tool is at the bottom of the photo.
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The end is then trimmed to leave about .020 past the groove with the cutoff tool

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The pin is then parted off
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Discussion starter · #9 ·
I received the wheels from Walsall and here is what they look like
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The first thing I do is mount them in the lathe and trim the back to reveal the spokes
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I then spot the axle hole
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and drill a 3/16" hole
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and finally ream it to 5 mm
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The wheel is then mounted on my home made arbor and the tread is rough cut
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The wheel is then mounted in the outside gaws of the chuck and the hub is turned.
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Here is the jig I use for drilling out the crank pin hole. this makes sure all of the wheels are drilled the same
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The wheel tread is finished on Dennis' lathe
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#10 ·
Hi Bill :
For my 2D2 9100 which I entirely rebuilt from an ex Kesselbauer model made for France Miniature amusement park who never paid for them, thats how I got it in a Paris hobby shop, I consider it as a scratch built engine as there is practically no items in it that I haven't modified on it I reshaped the body completly added considerable details (the metal straps on the bodywork had been done in plastic tape...) Rebuilt the chassis completly, turned new drivers, then junked the original transmition and made a new one with module 5 brass gears 2mm thick brass chassis for every reductor, ball bearings and Maxon coreless motors and brass sheet shrouding to protect the gears from dirt and crap it could pick up outdoors.It is direct drive (no worm gears) and nose suprended motors. Unfortunatly I considered that my machining skills were not good enough to tackle a real Büchli transmition, which wouldn't have stood up outdoors so well too.
One of the only thing on it I hadn't rebuilt where the two leading bogies, although I had added some details on them. So last year I decided to rebuild them completly and ordered castings from Mark Wood, as these had a large center boss which I wanted to find. His castings are superb, but pricey. I turned them pretty much in the same way that you described, except that to do the final profiling with a form tool I had bought on Ebay Deutschland I used a different Arbor as described in mark Woods advices on his site. This grabs the wheel at the rim with a dished washer up front so that the boss wont interfear. The idea behind his Arbor is that as his spokes are very fine if you hold the wheel by the rim during this last operation which does exert quite a lot of pressure, you won't break the spokes. Of course thes have an insulating bush for two rails, which is why the axle (thread on the arbor) is so big.


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Here is the finished bogie without all the brake gear, cylinder and axle guard:
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the rest of the engine can be seen in another post Ii did recently :
Getting back to building rolling stock, at last!
Cheers, Simon
 
Discussion starter · #11 ·
I have been remiss on posting and photo taking but here is what I have
Here is the cad drawing I used for the crossheads and a crosshead fresh off the mill. the mill steps are easily smothed over with a file.
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I use my own design for the expansion link. It is silver soldered together at the pivot and pivots on a double row of ball bearings.
At the far left is the pivot with the two bearings then going to the right are the pivot, the link back, two spacers, the link with the radius rod inserted. two link screws and the combination lever
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Here is the HP crosshead guide bracket with the link bracket attached and the bearings now set with 680 loctite
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and the LP setup
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And the assembled expansion link in place
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Discussion starter · #12 ·
here is a little more on the build
I have finished timing both chassis. Here are both showing the steam port fully open. it is timed so that the openings are the are the same front and rear. This centers everything and the valve opening timing is controlled with the combination lever.
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The tubing is installed on the LP chassis and then the valve covers and front cylinder caps. It has a successful air test and then the covers are installed. Next up will be the HP chassis.
Here id the LP in forward and reverse.
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Discussion starter · #13 ·
this is a mini valve i use for my lubricator and startup valve. it has a 4-40 thread
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And here are the valves in the chassis
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The axle pump and trailing truck are added. Here is a view of the underside
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And the top view
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The pilot truck needs some special attention because of the small wheels. I make a special bracket to step down from the frame rails
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And here is the rear truck suspension which doesn't require anything special because of the frame shape
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Discussion starter · #16 ·
A trackside detail cowcatcher is modified to attach to the front buffer
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The front deck is pretty plain, just a sheet of brass with what I believe is the pilot truck mount and a sand box
I had to modify the sand box to clear my steam piping so it has a cantilevered mounting. The soldering was tricky as I had to clamp the box at the very front where it was only thousands of an inch from teetering forward or baxkward,
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The deck and sandbox are then painted with low gloss black paint
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I still have a few things to do to the chassis but I am now starting the boiler and will finish them between firings

The boiler shell scales down to what would be a 2-1/4" copper pipe (2-5/8 OD). Since they don't make that size, I need to cut a 2-1/2" pipe down. The 1/4" reduction in the diameter results in a .785" reduction in the circumference. I mark the line to cut on the table saw with the additional marks for the saw blade width so that I don't cut on the wrong side of the line and then slide it along the fence for the rip cut.
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I cut the smokebox at half the cutout as it needs to be 1/8" bigger to go over the boiler
I use the cutout piece to reinforce the silver solder joint.
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Everything is heated to red hot to anneal then for forming.
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And then pickled in citric acid to clean them up for soldering
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The tube holes are drilled through the frount tube sheet and throat sheet at the same time
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And everything is soldered and cleaned up again. Note the PVC fittings which I used to form the round tubes prior to soldering
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Discussion starter · #17 ·
Here is the completed boiler and ceramic burner box.
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Here is the burner on the lowest gas setting. You can just see the orange glow. This is the premium ceramic material I have been using for years and my last piece. The material is no longer available through Bruce Engineering in the UK. I am hoping they will be carrying it again in the near future
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Here is it at medium gas
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And high
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Here is the two chassis with the boiler mounts. The two rear are fixed and the front is sliding and pivoting. I photo them in brass before painting so you cans see them better.
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and here the boiler and smokebox are mounted .
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