1/16 scale 1916 Case 65 HP Steam Traction Engine

[raveney]

Building a version of Rudy's Traction Engine. A big shout-out to Kim for his well read post "Steam Tractor-Rudy K" which gave me lots of tips and tricks for the build so far. Some enhancements so far are the grouters, thinner and increased number of wheel spokes, and extra stays and rivets.
Thank you for looking...

[Dave Otto]

That looks great, nice work!

Dave

[crueby]

Very good looking!

[cnr6400]

    Looking great!

[Kim]

Wow! That looks great!  You've gotten a lot done there!
Those rivets really gave me a run, but I got them worked out.  Hopefully you had an easier time of it? These were the first rivets I'd ever done, but most of the problem I had was drilling the boiler shell.

Your extra rivets really look nice!  Well done! 
Kim

[raveney]

Thank you for the comments and encouragement 

The rivets were done using a shopmade c-clamp rivet press. It took a lot of work to make it, but has paid dividends putting these rivets in as it is much much faster and more consistent. I started off with the more traditional rivet "snaps" for the cleats on the wheel rims and got fairly decent results just using 18 gauge copper wire. For the boiler shell I wanted to do better and leave the factory rivet dome on the outside. The rivet press is built upon a suggestion that another builder, Dennis, gave using a deep throated c-clamp.

I had a large piece of 3/4" x 4" steel angle and sawed the side off a short piece. Then it was chain drilled and milled out for a 1" x 8" throat. I machined the upper and lower snaps out of O-1 and hardened them after recessing using an 1/8" ball end mill as is typical.

I then sent away to Goodshall's for some high quality copper rivets. I have used almost 200 on the boiler shell so far. Very pleased with the consistent results. Used slightly larger 2.5 mm ones on the throat plates to simulate the side stays.

[Admiral_dk]

Impressive looking build so far 

Per                   

[raveney]

Thank you Admiral,

A bit of a milestone in the project today as the front axle was completed and the tractor is self supporting.

The axle was made to look like the image below using a narrower swivel pin and a fish-bellied center that was cast on the real version. Let me know if the plan is legible for anyone who may care to replicate this also. Not terribly hard to do for the extra realism.
 Looking at the LHS view it appears I may move the crankshaft forward so the flywheel rim is flush with the leading edge of the horn plates.

[raveney]

getting used to the image posting. Thought it would all fit

[Kim]

Beautiful job!  I really like some of the modifications your making to make it match the real prototype more.  It really does add some nice detail.  Like riveting that vent thing along the bottom front of the firebox, and the more complex hub you made for the rear wheels, just to mention a few that you haven't already named.  It really adds to the overall look.

As for the pictures - I think there is a size limit for one post too, in addition to each picture, but I'm not sure exactly what it is.  You can attach a max of 8 pictures per post, but I don't remember what the max size is.

If you host your images somewhere else, you can embed them in your text if you want. Then there is no limit on how may pictures you can have in one post

Great work, Raveney,
Kim

[Dave Otto]

That looks great, always nice when you can add details to a model that makes it stand out from the crowd. 

Dave

[crueby]

Max total is 10mb, max single is 1mb, 8 images max.

[raveney]

Thank you for the photo hints. I coulda swore I reduced the image size, but it seems I need to double check using properties because they swell up again
Here is an update on the sheet metal work. I built the parts per plan and then changed things around to make it more like the real bunkers using trapezoidal boxes and making them tuck in behind the wheels. Of course I added a ton more rivets, cause the rivet press is so much fun to use.
I needed to change my bandsaw blade to 24 tPI instead of the everyday 8-12 TPI one. It cuts very nice like that in the vertical table position, but hearing protection is a must. That makes the one who must be obeyed happy also.

[RReid]

Nice job on the sheet metal work. That's looking really great!

[crueby]

Looks fantastic!  How did you bend the corners to get the different  radii on them?

[Kim]

Great sheet metal work!  It's always a challenge to get things to come out square and on size.  Beautiful work 

Kim

[wagnmkr]

Very crisp and clean metal work, and the same question as Chris?

[raveney]

Thank you very much for the kind words,

I had built a crude sheet metal bender  for a previous project and the fence has a radius/set for 0.110" aluminum sheet. I experimented and made radius larger until pieces didn't crack. It is a bit large for 1/32" steel, but where I wanted the radius smaller like in the seats for this model, I worked the corners in a vice with soft jaws.
I believe the better commercial units like Baileigh may have an adjustment that slides the fence closer or farther based on gauge. I may be able to modify mine?
Great question, I'll look into that more...

[raveney]

Carrying on with the build....I am using a Case catalog for detail work and wanted to include the grab bars at the rear bunkers. Wasn't having any success bending two bars the same so I diverted into building a duo-mite clone bender. The China clones are readily available online, but had terrible reviews.

The bender worked great, but took a long time using the scrap steel that I had on hand. I plowed ahead because if I had to purchase materials, it wouldn't have made sense to make it from scratch. Probably easier to rebuild the crappy clone.

[Kim]

Wow! Those grab bars really look good!  Definitely worth the extra effort. 

Kim

[raveney]

Thank you Kim,

I used the bender again making the smokebox door latches. Really repeatable results, I broke two of them in the same place . Below is an updated photo of the build. The chimney was made in two pieces similar to what I observed online, and held in place with #2-56 screws. The smoke box door and frame are several parts silver brazed together. I even made a plump "Abe the Eagle"
It's harder than it looks...He's only about 3/4" high.

[Kim]

Wow!  The door and smokestack look great!  As does the eagle!  Did you freehand carve him?  That's just amazing!  Beautiful detail 

Kim

[RReid]

Really fine looking work. That eagle doesn't look easy at all, but came out great!

[Admiral_dk]

Amazing details 

Is that the 'Original' on the photo/poster in the background ?

Per         

[raveney]

Thank you guys!

I free hand cut and filed the eagle by scaling an image I took at a local show, Florida Flywheelers, and some circles/center marks. The globe is approximately 3/8" so a 3/16" radius gauge helped keep it sorta round. It started looking a lot like a duck, and I kept filing using magnification and a set of needle files until it started looking leaner and meaner. Should be able to enhance it a little more during final paint.

Yes the rusty tractor in the back is an earlier version, but has super good details that I am using as I go. There is quite a bit online to go by as inspiration. Has everyone seen the story about the Case 150 that was built out in the midwest by Kory Anderson? Very inspirational...

https://150case.com/

[raveney]

Now onto some more serious machining
I chose to cut my own gears and had already spent a considerable amount of energy making a 48 DP 20 degree set of cutters based on Mr Ivan Law's book [Gears and Gear Cutting]. I needed to make another cutter for the 120T bull gears and started by hardening a 0.670" button and mounting it in a tool. The discs are 0.156 wide, 2.0 diameter O-1 tool steel and are made using a concentric arbor, but used in an eccentric one presenting one of the two sharp profiles. Fairly easy to make and now I almost have a complete set!

Next I will attempt to knock out the 20T worm gear and worm while I have my rotary table set up and true (over $50 for the pair if bought). I have never made worms or worm gears and the chapter looks to be pretty complicated 


In the last photo, the two small pinions to the right of the index tool are rejects. I didn't dial in the 4 jaw scroll chuck when I transferred the arbor from lathe to rotary table and  it has nearly 6 mil runout.  :wallbang:I can tap the mounting plate true each time to correct that.

[Kim]

Nice work on those gears!   

I've used that button method to make gear cutters before and it works really well.  Ivan Law's book is quite a resource!

Kim

[raveney]

 Hello,
Used a short 3/8-16 bolt for the worm and hobbed the gear using a tap. Infeed 0.040" seemed to work good. Watched a few videos about this method, and seemed to be appropriate for this use.

The rest of the spur gears got some fancy yet time consuming detail work to mimic the real ones. Then small hub spacers were soft soldered on using a well blackened SS rod to keep everything concentric. I also made some 1/16" spacers to push the gears out away from the wheel spokes.

Had planned on making the cross braces inside the rims, but not so sure anymore. 

Next I will make some brass bearing blocks and rivet them to the horn plates. Shifted the forward crankshaft hole for the pinion gear as expected to clear the flywheel and mesh well with the new gear ratio.

[RReid]

That's a nice looking gear train! Interesting approach for making the worm gear too. Well done!  

[Kim]

Those are some mighty sharp looking gears you made!   Very nice! 

Kim

[Krypto]

Lots of work, but that really makes the gear train look realistic!

[Admiral_dk]

Beautiful Gears  + it looks like you have then Mesh really well too 

Per       

[raveney]

Wow, I really appreciate the positive feedback on how the gears turned out.
 

The mesh was set using the DRO on the mill and 1/4"dowels rather then the calculated pitch diameter and they do turn very smoothly. I spent extra time tapping the chuck of the rotary table true before cutting this set, and that seems to have made a very big difference. The 1916 Case catalog had a very detailed sketch of the gear train which I referenced for the different spokes and slots of the model.

thank you all for watching

[Kim]

Wow!  That's quite an interesting picture!

So, what's all the curved spring looking like stuff in that middle idler gear?  Is it like a cut-away view of what's inside the gear or something?  And is that bevel gear behind it?  Is it some kind of clutch mechanism or something?

Kim

[raveney]

Hi Kim,
I believe that is called the differential gear. Its explained well in another Case Owner's Manual online. Basically its similar to the detroit locker or posi traction in the muscle cars allowing one wheel to slip going around turns, but locking them together when inline.

I skipped a working version. Also skipped the clutch but want to figure out a way of disengaging the idler gear so the model could run while staying stationary; maybe just sliding it outward.

[internal_fire]

Basically its similar to the detroit locker or posi traction in the muscle cars

Actually the differential is much simpler. It merely allows the wheels to rotate independently in turns while driving both at an "average" rotation speed. There is no locking at all in the manner of posi-traction. If one wheel it in the mud and the other on solid ground the mud wheel can take all of the "average" rotation and spin freely.

The springs are just shock absorbers for the entire gear train.

Gene

[Kim]

Fascinating!  That's really cool.  I never realized that these traction engines had differentials. But of course, they'd need it! 

Kim

[Zephyrin]

I too made a 1/16 scale steam tractor several years ago, largely copied from Len Mason's Minnie.

A complicated set of pins allows to have either the 2 rear wheels coupled to the axle for straight running only, or only one wheel coupled to the axle, the other wheel remaining free for running in curves and finally a shorter pin, where only a cable drum is coupled to the axle, to pull a load with the cable with the wheel brakes applied...

Obviously it's quite inconvenient to use, and I must admit I don't play with it very often; I did a demonstration at my club a few weeks ago.

https://photos.app.goo.gl/Z7y6RQHvE7wFMwAk8

the differential gear was not present on some traction or ploughing engines, the picture below shows the dowels' disposition

[raveney]

Thank you for the additional information and correction

Hard to believe that a tractor that lived mainly in dirt fields didn't have a locking differential, but if I had bothered to read the catalog carefully I would have known that too 

Here is a video of a fellow that made one that works on a Burrell tractor
<a href="https://www.youtube.com/watch?v=O7qYsHtSlTM" target="_blank">http://www.youtube.com/watch?v=O7qYsHtSlTM</a>

[internal_fire]

Hard to believe that a tractor that lived mainly in dirt fields didn't have a locking differential, but if I had bothered to read the catalog carefully I would have known that too

The differential did not lock, but there was a lock available.

Starting from the gear attached to the clutch there was an idler gear and the ring gear around the outside of the differential. These three gears were constantly in mesh, with no way to disengage.

The left-side bevel gear on the differential was keyed to the countershaft. The left end of the countershaft was rigidly attached to the left pinion. The right-side bevel gear on the differential was directly attached to the right pinion. The right pinion was mounted on the countershaft, but it was not firmly attached to the countershaft. It could rotate freely. Both pinions directly drove their respective bull gears.

This arrangement provided the typical differential arrangement allowing the wheels to move independently as needed.

Locking the wheels was provided by the rear axle.

In normal operation the right wheel was pinned to the rear axle and the left wheel was free to rotate on the axle, with only a keeper to prevent the wheel from falling off. The pinions drove both wheels (separately). The axle did not provide any motive torque.

To lock the wheels a pin was inserted into the left wheel keeper in order to lock the keeper (and axle) to the wheel. Now both the left and right wheels were locked to the axle. The differential played no real part in the locking, but of course it continued to provide the drive to the pinions and bull gears. The axle could carry a lot of torque if one of the wheels wanted to slip or virtually none if the wheels were both on firm ground.

I suspect the springs in the differential functioned both as shock absorbers and as slack to accommodate possible rotational misalignment from the rather crude axle locking system.

Gene

[raveney]

Hello again,
Traditional looking fasteners were made to replace temporary screws in several places as I needed to lock down the side "horn" plates to the engine. Had to fill in a shaft hole that was drilled earlier at the drive pinion. I opted to use bronze TIG wire and clamped the thin sheet to a brass backer bar to avoid distortion.

Then made the shaft bearings and riveted them to the sides after careful alignment. I gave a small radius feature to each on the visible inside face. This was for looks and because the rivets I had were too short for a full width bearing.

Next I will attempt to replicate a functional clutch so the boiler can steam while remaining stationary like the real one. Several iterations of design, but decided to clone the real Case clutch design after considering the theoretical friction of the thrust bearing versus clutch shoes.

I don't know if this will work, but it looks feasible so far.

[Kim]

That clutch will be a great detail on your tractor!  Very interesting! 

Kim

[crueby]

Thats prety cool - how does the cluth get engaged? Does the gear/hub slide on the axle?

[raveney]

Yes the pinion gear is connected to the center link that slides over the crankshaft. The center link spreads the rods to force the clutch shoes against the flywheel.
It seems to function as tested here...
<a href="https://www.youtube.com/watch?v=YRN3ubRRd6c" target="_blank">http://www.youtube.com/watch?v=YRN3ubRRd6c</a>

[raveney]

I attached a marked up copy of the CAD model showing the direction of force vectors. I sketched it out as a determinate statics freebody diagram and calculated the shoe friction forces and it seemed that the smaller the angle is between the spoke plane and the rods, the higher mechanical advantage the input force had. This way the friction when pushing against the pinion gear hub doesn't kill the engine rotation much.
I hope to refine the engagement mechanism  so a scale lever will engage and disengage the shoes. Right now the "clutch fork" wants to walk out of engagement as the pinion rotates against it. The real one would have a thrust collar here I believe?

[internal_fire]

I have spent a lot of time studying plans for the Case 65, and I think I now understand the clutch mechanism.

Your version is very, very close to the original. Yes, there is a collar to separate the over-center parts from the pinion.

Here is a sketch that shows the basics.

Gene

[raveney]

 A few more parts this week for the case 65 HP,
First crankshaft flywheel was too small, second one looks better. I measure the pictures and do a ratio comparing to the wheels or boiler shell (known diameters)
Made a crosshead cylinder and support that will sandwich between crosshead and cylinder head. It will also support the maintenance shelf and steps.
The crosshead on Rudy's plan is much simpler, but this one was used by Kim on his build and looks much more representative to the real one. I would have liked to use more studs/bolts than the four, but it appeared that they would interfere with the steam passages and exhaust port.

[Kim]

The larger flywheel and crosshead look great! Much better proportioned to the substantial machine that this truly is! 

Kim 

[Roger B]

Excellent    I like the way you are calculating the forces in the clutch mechanism 

[Zephyrin]

the clutch mechanism is very clever and works perfectly, well done.
does the hexagonal part for adjustment have left and right handed threads?

[raveney]

Thank you for the compliments and comments,
 
this project is a lot of fun as I am able to deviate from plans often and there is a lot of reference materials online.

I assume that the hex should have both left and right hand threads, but I omitted them as I don't have the LH dies or taps for 2-56 thread. I'm not sure they even make left hand taps this small?

I still thought hex threaded couplings were needed. Adjustability was necessary to ensure equal lengths, and I set that using two drill bits through the clevise ends of both rods. Then I secured them using green loctite. The shoe friction is then adjusted by how far the flywheel is pushed onto the shaft.

For now I have tiny strips of work glove leather attached on the shoes using contact cement. Should last a while?

[raveney]

image to better show what was meant about hex couplings and adjustment of clutch

[Krypto]

You are doing some great work here!  It will be interesting to see how the clutch works under a load.

PM models has LH tap & dies at 0-80 & 1-72 if you feel the need (also found LH 2-56 at various other places).

The leather should hold up well.  Back in the day, I used to race nitro-powered RC sprint cars and my car was using an aftermarket brake system that was basically a brass strip with bonded leather wrapped around an aluminum drum.  The leather held-up well for several seasons in a much harder use case so in your engine it should last practically forever.

[raveney]

Thank you Krypto,
A few more weekends and I might be able to test it on air.
Continued work on the steam engine parts. Mainly using Rudy's excellent book but made dimensional adjustments to make the modified crosshead and flywheel work out.
I used a bit of 304 SS for the piston rod, and thought I was going to have a fit threading it, but it went fine. Used bronze offcuts for the piston and valve. Still need to make one more gland nut and I can put it together for keeps.

[crueby]

Great looking parts!       Following along here. 

I also tried some 304 stainless on a recent project, never again! It work hardens really quickly.

 

[raveney]

Well the troubleshooting and fitting up of all the engine components seemed to take longer than making them. I used graphite yarn in place of a ring and it was pretty hard to keep it intact while assembling it all. Kept getting stuck on the sharp edged steam passages at the end cover. Also had a bugger of a time with the valve rocker until realizing that the bottom pivot needed to be slotted. Rudy notes this, but I missed it. Another hurdle was my valve spindle would unthread out of adjustment, and the engine would start and then slow down and stop. Jam nuts fixed that. Lastly the whole design of using set screws on a shaft that needs to slide into bearings is not great. After I figured out the final position of the slip eccentric, I made another shaft and keyed the engine flywheel. Whew!

Thanks to Kim and other builders for the tips. The clear steam chest cover was very useful. I'm sure I saw it somewhere, but wanted to include two maybe useful shots of how I cut the circular gaskets, and how I made the drain cock spindles. The dremel stone was the only way I know to make a taper on SS screws. Everything else just bends or snaps them off.

I have a recycled refrigerator compressor that is extremely quiet and a good way of running in new engines. I left everything to run both directions and shot 30W all over to quiet things down. Unfortunately this soaked my leather clutch shoes so I made new ones a bit longer and clamped them in place with a hose-clamp while the contact cement was curing.

If I had steering I would let it crawl around.

See you next weekend!

Finally everything works, so made a short video of it starting, reversing and how good the clutch can grab (stalls the engine on air).
<a href="https://www.youtube.com/watch?v=Ik_8SeqAZVs" target="_blank">http://www.youtube.com/watch?v=Ik_8SeqAZVs</a>

[Kim]

That runs great!  In both directions!  What more could you ask for 

Kim