25 HP Nash

[minh-thanh]

Doug !
Nice gears !
The gear you made it is correct in diameter , angle .... ?
Thanks !

 

[Sprocket]

Chuck and Minh Than, Thanks! I like them.
Minh Than; I think they are. The cutter to make the hob was a 40-degree point which should make a 20-degree pressure angle. The outside diameter is set by the number of teeth and the diametral pitch (32 for these). I don't know how they would mesh with commercial gears, but they mesh with each other.
The tool is just visible on the left, about to cut the fifth ring. It looks like a threading tool, but 40-degrees.
That was probably the hardest part to make and get square to the work. Where you'd use a fish mouth to square a threading tool, I made a 40- degree piece to square this tool.
Hope that helps,
Doug

 

[minh-thanh]

Doug !
Thanks.

I don't know how they would mesh with commercial gears, but they mesh with each other.

Anyway your gear is look better than mine .

 

[a41capt]

Doug, I’m looking at the “Odds and Ends” by Phil Duclos as a build after “Pioneer”. As I don’t have the required spur gear cutting tools, do you recommend going the extra mile and building the modified gear hob you built, or putting up with the thump-thump-thump of the Duclos profiled single tooth cutter?

Nice looking gears BTW!
John

 

[Sprocket]

John,
Having done it both ways, I'd make the hob. I think the tooth profile is better when it is hobbed, and gentler on the blank. You can cut full depth in one pass, don't remember for sure, but I don't think I did with the single point cutter.
Doug

 

[a41capt]

John,
Having done it both ways, I'd make the hob. I think the tooth profile is better when it is hobbed, and gentler on the blank. You can cut full depth in one pass, don't remember for sure, but I don't think I did with the single point cutter.
Doug

Thanks Doug, I’ll have to give that method a try.
John

 

[Sprocket]

In the past, when I've made a muffler, it's just been an expansion chamber, maybe another bit of pipe, and a flapper. This one is different.
This one is water cooled. I measured the distance for the exhaust flanges, and it is slightly different than the plans, so I made the muffler to fit.

The plans show a curved end on both the exhaust and coolant flanges. I left the ends square and made a hole to braze them into.
And the same for the coolant flanges.
There are holes drilled through the length of the muffler, one for exhaust, the other for coolant. The coolant channel is drilled on an angle from the center of the flange to miss the exhaust channel and hit the coolant. I started the hole with a ball end mill, then rotated the body and drilled in the side of the ball depression.




I made a mock-up of the cylinder to hold the flanges in the correct orientation. It held things well but was a pain to get apart.


end caps are bolted on with 1-72 hex head fasteners.

More in a little while.
Thanks for looking,
Doug

 

[Sprocket]

After a bit of silver brazing and a lot of cleaning up, I have a muffler. There are plugs in both ends of the coolant through hole, but not in the exhaust. I waited until the parts were together to drill and tap the 0-80 holes in the coolant flange rather than try to hold an alignment as I brazed.

The plans show a curve at the end of the exhaust pipe. It's thin wall 5/16" brass, and even when annealed, it didn't bend well.
So, I thought I would make a bend fitting. I sliced the tubing most of the way through a number of times, then flexed it and soft soldered it.


It looks better than my attempt at bending, but still a little rough. I may try slitting the exhaust pipe itself and not have a separate fitting or try one of the other methods I've seen in recent posts. I've used sand in larger tubes, but ice sounded like a cool idea.

In looking back at pictures, I find the first parts I made were on 12/30/2020, so I have been at this a year. Pretty soon.
I'm getting down to the little things that connect it all together.
Anyway,
Thanks for looking and Happy New Year!
Doug

 

[a41capt]

I like that transition piece Doug. Great workaround toward getting a smooth bend. I may steal that idea for future tubing bends!

John W

 

[Sprocket]

John,
You're welcome to it. It felt a little flimsy sticking up like that, but I think if I had lowered it further in the V block it would be better.
I have used a similar method for bending angle iron, sometimes cutting out little triangles. I couldn't see that working here.
Doug

 

[a41capt]

John,
You're welcome to it. It felt a little flimsy sticking up like that, but I think if I had lowered it further in the V block it would be better.
I have used a similar method for bending angle iron, sometimes cutting out little triangles. I couldn't see that working here.
Doug

One of my jobs during my time in the US Navy was sheetmetal work. Building sheetmetal transitions for everything ranging from 10 inch ductwork all the way up to 8 foot plenums for air supply to boilers. Geometric layout and construction required some careful work, especially on multiple angle transition (bends) to accommodate different shipboard applications.

However, cutting those transition angles in such a small piece of tubing would be damn near impossible. Your work around was a real high class job!

John W

 

[Sprocket]

I decided that I'd better get the "peripherals " ready so I can run this thing soon. I think the only motor parts I have left are the crankcase doors, standing platform and handrail. So, other stuff. There is one water pump in the book for any of the motors.
I made it mostly per the plans but used a different lip seal as the specified one seems to be hard to find.
It starts with a pretty good chunk of aluminum.

Bearing side, and impeller side. Then drilled and roughed out the shape.

I made the inlet boss a little long so I could grip it in a collet and face the other side to thickness. When I drilled the mounting holes in the
cover, I went deeper into the parent stock so I could tap those holes and mount the cover back on it to shorten the inlet boss.
Together, but nothing inside yet.

Going to run out of space.
More a little later.
Thanks for looking!
Doug

 

[Sprocket]

The bearing is bronze, pressed into the case. There is an oil groove in the middle of the bearing, .020" deep and .12" wide. I don't have any boring bars that will fit into a 3/16" hole, so this is what I came up with. It took a couple of tries at different shapes, but this is the one that worked.

and I did get a groove in the middle of the bore. An oilcup feeds oilcup feeds oil to the groove.
The impeller is made with the four fins soft soldered to the hub. I made a little fixture to hold the fins in position while i soldered them in.
Then flipped the rotor over to solder it to the shaft.

I was a bit concerned about turning the rotor to size and thickness, but it worked out. None of the fins flew off, and nothing got bent.



I guess the next "peripheral" is the propane demand valve. And a coolant tank. And some pulleys for the pump. Yeah, a few more parts.
That's all for now. Expecting snow overnight.
Thanks for looking!
Doug

 

[Sprocket]

Coolant tank and piping.
I had bought a piece of 2.5" DOM tube to make the coolant tank. It's a simple piece of pipe with ends soldered in.
I made the ends a little thick and over outside diameter so I can blend them and round the corners after soldering.

I wanted the legs to look as though they were cast, and so "mill whittled" them from pieces of 1/2 steel plate. Where I could, I used a 3/16" ball end mill to make fillets, and filed and sanded the edges to make a rounded corner.






That was a lot more cranking the rotary than I thought it would be, but I think they came out as I'd envisioned them.
There will be a brass strap for hold down with a clamp into the ears that stick out.
More later,
Thanks for looking!
Doug

 

[Sprocket]

I don't plan to have an actual radiator, so there will be sections of brass fin tube in the coolant loop.
My plan is to have them mounted on the top of the tank. They are 5/8" brass, ends threaded for mode tapered pipe (1/4"-40)
and finned with .050" fins and .050" grooves. I ground a tool to make the grooves as I didn't have a parting blade that narrow.

I still have to make stand offs to mount the "U" on the tank, and some tank fittings. Coolant will enter one end of the "U", and run into the tank
at the other.
Again, thanks for looking!

Doug

 

[Sprocket]

It's been several busy weeks, but not in the shop. It has also been slow going because I am making the cooling system up as I go along. There
are no drawings for it, and sometimes using my imagination consumes a lot of time. (I get a little carried away) But here is what i came up with.
The standoffs to mount the fin tubes on top of the tank started out like making the big ends of a connecting rod

The mount holes end up being 90 degrees to each other. The tank ends were left thick so I could round them and blend with the tube after
they were soldered. Two straps/clamps attach the tank to the legs

There is a filler with venting on top between the fin tubes, an inlet fitting, and an outlet.

I guess I didn't get a picture of the outlet, but it's just a disc with a hole and a tube soldered in.



So this is the cooling system. I guess I'll make pulleys to drive the pump next. I got 1/8" timing belts, and I'm trying to figure out if I can cut slots in the pulleys
to drive the belts or just depend on friction.
Thanks for looking,
Doug

 

[kuhncw]

Doug,

Nice work on your cooling setup. That is an interesting design.

Chuck

 

[Sprocket]

Thanks, Chuck. I hope it fits with the era of the motor. I have no real idea what the original was like.
Doug

 

[gbritnell]

Great looking cooling setup! I don't know that it's period correct but as nice as it looks, who cares.

 

[Sprocket]

Thanks, George.
It was kind of fun to try to imagine what it might have looked like in 1898, with maybe a little "steam punk" thrown in.
Doug