1.75” Minnie traction Engine

[chucketn]

Just got caught up with this thread. Nice work, Mark. Please elaborate on the roller for the wheel rim. Could it roll mild steel for a flywheel rim? Plans?

Chuck

 

[dnalot]

Please elaborate on the roller for the wheel rim. Could it roll mild steel for a flywheel rim? Plans?

I saw your post about rollers first and I posted a photo of a roller there. I think I will try and make one in the near future. I have to stay away from welding smoke for at least another 6 weeks. I need to roll 10.5" Dia. by 2.5" wide by .25" steel or brass.

Mark

 

[Jasonb]

You don't need to make the rim that thick, one of the problems with scaling up the Minnie which was a bit chunky to start with. There are plenty of 2" model traction engines running with the rims from 1/8" material and the tees welded in, they would have 12-13" dia rear wheels.

 

[gus]

Hi Mark,

Your post on the boiler is very useful for me as I have been wanting to build such boilers. Due the complexity,I gave up. Would have to invest in brazing torch. The Mapp Gas Torches is not exacty for very small boilers.

 

[dnalot]

You don't need to make the rim that thick

Thanks for the info. I think I will do as you suggest.

Mark

 

[dnalot]

Hi Gus

Would have to invest in brazing torch

It took a lot of heat to bring so much copper up to temp. I used a ceramic insulating blanket and fire bricks to help hold in the heat. The biggest problem I had was chasing the few leaks I had. It was like a game of "wack -a-mole". I used more gas chasing the leaks than I did the first go. You need to keep all of your openings for fittings OPEN during the soldering to help keep inside and outside pressure equil.

Mark

 

[gus]

Now I see good reason why my mini 1 1/2''O.D. -----------2'' O.D. Copper boliers weren't brazed as good as yours. Will put together a DIY Brazing Hearth sometime later. Plan to buy Oxy- Acet. Equipment. Thanks for showing the way.

 

[dnalot]

Hi

I have completed the rear axle assembly and the tender.

The rear wheel hubs I made from brass flat stock, soldered together. The drum for the wench I turned from aluminum.

The tender was made from brass sheet. The sides were fairly easy to form but the heat from annealing warped the sides some and I had to fight with that moving forward. I was a little apprehensive about driving the rivets with a rivet gun do to the thin stock I was working with. As it turned out the rivet gun worked out just fine.

The rolled edging at the top of the tub I made from .25 half round. I used silver solder to join the parts together and then used soft solder to attach the edging to the tub. At the same time I soldered all the joints of the water tank to seal them.

I still have to drill some holes for mounting several parts and the bulkhead that forms the coal box. After I do that I will do the final sanding and polishing of the tub.

 

[dnalot]

With the Tender mostly completed I turned to some of the details that connect to the tender.

First up was the roller guides for the cable. The rollers made from drill rod actually work.

Next I made the jack screw and clamping band for the brake. The band was salvaged from banding used to hold band saw blade material in a roll. It was a perfect size and it was springy.

I followed that with the quadrant for the control rod that will but the engine in forward, neutral or reverse. It still needs to have notches cut into it but that will have to wait until I have the engine built.

I altered the plan by putting the valve for the return water line from the water pump inside the water tank. I soldered the valve to the bottom of the floor plate just below the steering wheel. The valve can be turned by an extension that puts a control wheel near the top edge of the tender.

The final detail of the tender is a bulkhead that provides a bin for coal.

With the tenders details completed I went ahead and put the final finish to it as I don’t think it will be separated from the model again. Most of the parts I plan to let age naturally, but the tender looked rather bad after soldering and cleaning around the rivets proved to be difficult. So after sanding and burnishing I used some acid and burnt oil to age it a little and then hand rubbed it with lanolin and light oil.

I have also completed the steering system. I bought the worm gears as I’m not up to that challenge yet. I did make a change to the original plan when making the drum. I made it in two parts so that when the chains are installed I can rotate the two halves to adjust the slack in the chain before locking the drum in place with a set screw.

Well I can’t put it off any longer so next up is the wheels. The hubs are done so it’s time to make the parts for the rims and the spokes. And then I need to make an assembly jig for assembly. Unfortunately my wife wants some work done in her kitchen so I may not get to start for a few weeks.

Mark T

 

[dnalot]

Hi

I'm back in my shop and its time to make some wheels.

The first step in building the wheels is/was to make a tool for rolling the rims. The tool is not my design, I saw an example and scaled it down for my use. The tool was made from bits and pieces around the shop and took me about 5 hours to make. Rolling the two rims took less than 10 minute and was almost effortless. I expected some slip of the driving roller but that didn’t happen. The rim was rolled from a 36” strip of half hard brass 2.5 inches wide by .125 inches thick. That will allow for about 1.25” to be trimmed off the ends of the rolled ring. I think the lower limit on size will be about 3” diameter rings. The one in the photo is about 11” in diameter. The photo showing the parts is missing the two 3/8-24 bolts that are used to jack the lower rollers up towards the work.

With the rims rolled I am now making a fixture for turning the inner flanges of the rims. It will also serve as an assembly fixture and will work on both the lathe and the mill.

 

[dnalot]

Got a little more time in the shop and have made a little more progress.

After rolling the rims I rough cut the parts needed to make the flange that the outer end of the spokes mount to. Each ring was made up by silver soldering 4 pieces together. Four rings are required for the two rear wheels, I mounted all four of the rough cut rings to a fixture plate adapter on the lathe’s flat wheel, and turned them as a group.

With that completed the next step was to silver solder the flanges to the rims. I then sand blasted the rim assembly and mounted the rims to the fixture plate and mounted that to an indexer on my milling machine. I needed to drill the holes for mounting the traction cleats to the rim, but the wheel was too large to be drilled with the mill so I fashioned a drilling jig and drilled the holes with a hand drill. There are 72 cleats for both wheels and it was boring making so many parts. It was fun driving the rivets however and the rim really started to look like something with the cleats mounted.

I then mounted the rim assembly and the wheel hub to the fixture plate and measured for the spokes. Each wheel has 16 spokes and each had to be made and bent to fit properly to the wheel. I thought this part was going to be a slow process but fitting the spokes turned out to be quick and simple to do. At this point I deviated from the plan as the plan called for soldering the spoke to the center hub. My parts fit very tight so I simply drilled the hub end of the spoke for a pin, and used loctite to glue in the pin. I then made a custom bucking bar for driving the rivets that secure the spokes to the rim assembly. And again the fun part was driving the rivets.

The wheels turned out surprisingly round and they turn true. The last driven rivet wasn’t even cold before I had the new wheels mounted. The rear wheels measure 11.25" in diameter. I have now leveled the engine and measured for the center of the front axle to the ground. With that dimension it’s now time to start building the front wheels.

Mark T

 

[10K Pete]

That is one beautiful engine!! I'm in awe of your workmanship in building
this. It will be very exciting to see it under steam!

Pete

 

[Herbiev]

Thats a very classy looking machine. Looking forward to seeing it in action

 

[dnalot]

Hi

Thanks for the kind words guys. Yesterday I made the rims for the front wheels. Today is another day at the doctor's office but I hope to have the engine sitting on its wheels by the weekend. I'm chomping at the bit, wanting to get started on the engine. "Saved the best for last"

And I would like to give Space-X two thumbs up on the landing of their booster rocket yesterday.

Mark T

 

[dnalot]

Hi

The front wheels are a simplified version of the rear wheels and I used the same fixture and procedure as before. I have aged the wheels to a nice chocolate brown with dark red highlights. After aging I soaked them in oil and wiped them down. After the solvents dry off I will rub the wheels down with a soft cloth to bring the shine back and a few more highlights.

And as you can see I have started the flywheel. The rough lathe work is completed and the next step is to mount it to a turntable for cutting the six spokes on the mill.

Mark T

 

[10K Pete]

Aww Mark, those are beautiful wheels! Coloring is just perfect.

Pete

 

[idahoan]

Beautiful work Mark!

I'm just catching up here, and am in awe at the fine craftsmanship you are putting into this project.

Dave

 

[Jasonb]

Just caught up with teh last two updates and the wheels are looking good.

I notice that you said you "leveled " the engine, it should actually slope down towards the back. With the boiler level on teh 1" the front wheels should be 3/32 below the rears so about 5/32" on yours.

 

[dnalot]

Hi

I notice that you said you "leveled " the engine, it should actually slope down towards the back. With the boiler level on teh 1" the front wheels should be 3/32 below the rears so about 5/32" on yours.

I guess I should have said I adjusted the engines attitude. I have the barrel of the boiler sloping back to the rear by .5 degrees. That comes out to 3/16" higher at the front axle than the back.

10K Pete, where in washington is Nordland? Is it a town or just a post office.

Thanks for your comments guys. Your fueling my desire to work harder. Today I start cutting spokes into the cast iron flywheel. I bought the 8" x 1.5" round of iron from McMaster Carr. It is the nicest cutting cast iron I have encountered.

Mark T

 

[10K Pete]

Mark,
Nordland is on Marrowstone Island inside Mystery Bay. We're about 5 miles
ESE of Port Townsend, across the bay. We have a post office, general store and a boat canvas maker right in downtown. Just north a few hundred
yards is Johnsonville with the oyster company and construction company.
The only reason you can't miss Nordland driving by is that if you go fast
enough to miss it when you blink, you'll run off the road into the bay!
Nice small and quiet.

Pete