Tiny Power M

[johnp]

Last year i built a Ray Hasbrouck #10, (2hp simple, without castings) I put it in my 18' boat and used it last summer. This winter i'm thinking about builting a Tiny Power M for the same boat. Can anyone tell me how difficult this engine will be to build from the castings, and how long it will take?

[DetroiTug]

The M is a relatively easy engine to build. All straight forward machining. A 12 inch lathe and small vertical mill is all that is needed. CNC will make it easier, but it's not imperative. The only part that would be rather difficult to manual machine (but, it's doable)would be the Stephenson link, and they sell that finished. I believe they told me that they will machine any of the parts for the builder. Another good reason to get one of their casting sets is they typically have everything in stock, and they have been around since the 50's, so they'll probably be around a lot longer - if I need something.

I really like those engines a lot. I'm using the Twin M in the tug now, I have not had any trouble at all with it. It's a very smooth running,
well-balanced and durable engine. The wide flanges of the uprights on each side prevent the crank from slinging oil out on the floor. In the archives on this forum there is a thread that covers mine sorta ( 1958 Tiny Power).

http://www.thesteamboatingforum.net/for ... f=22&t=110

-Ron

[johnp]

I was planing on building a simple 3x4' the twin might alittle to much for me to build.

[DetroiTug]

There is really not a lot of machining difference between the single and twin, except the base and crankshaft. The twin is essentially two singles. The Hasbrouck turned out really nice, I'm certain after that, the M shouldn't be a problem. You asked how long it would take, depending on how much time you have to devote to the project. Working on it part time, a few months to build.

Just a note, I originally went with the piston ram pump they sell, it works good, but the hypro I added works a lot smoother. They do have a combination air and water pump that runs off of a chain reducing ratio to scotch yoke; that is not on their website, but works really well. I seen one on the 3-5-4 compound they sell. The guy said he got it from them.

-Ron

[marinesteam]

Last year i built a Ray Hasbrouck #10, (2hp simple, without castings) I put it in my 18' boat and used it last summer. This winter i'm thinking about builting a Tiny Power M for the same boat. Can anyone tell me how difficult this engine will be to build from the castings, and how long it will take?

You already have shown that you have the skills to build the M by building the Hasbrouck. The only difference is that the stress factor might be a little higher with a build from castings over a bar stock engine. With castings you do really need to take your time and do a complete survey of the part before making chips. The goal is find the part in the lump that you get as a casting by making sure that you have material for all of your operations. The stress comes from the fact that you can't just grab another piece of bar if you make a mistake. Be deliberate and double check yourself before all of your cuts and you'll be fine.

Good luck and keep us posted as you progress.

Ken

[Mike Rometer]

Take the 'skin' off the casting on all the machined surfaces, before you try to take any of them to size to size. If the pattern maker has done his job well then there will be plenty of machining allowance. Then pick a datum surface and go from there after careful measurement. Castings intended for amateur market will often have extra machining allowance.

[DetroiTug]

Tiny Power does leave ample stock on their castings, almost too much really. Yes a little higher stress level as the castings are essentially a one-shot deal. As with most machining, use a good setup, as Mike mentions establish a reference surface that the rest of the cast part is machined from, then check, check and re-check before cutting.. A few tips: The biggest issue is parts pulling out of the vise or moving during cutting - that can be remedied by some paper lining the front jaw or in between set up surfaces, or in more severe cases a strip of emery cloth. Also, regarding drilling bronze; make sure and take the rake off of the drill bits, or set them at 90 degrees. The rake is the angle on the frontside of the cutting edges, it should be parallel to the centerline of the bit. Bronze and brass are soft, the bits if ground aggressive can pull themselves in to the material . This applies to drilling polycarbonate etc, as well. It doesn't take much, just enough to remove the sharp edge.

Ron

[Mike Rometer]

I usually find that after de-skinning I can get a better grip of the casting. Having decided on the datum face I can bring that to size AND true it to the mass of the casting. From there on in, it should get easier as each face is completed. Some prefer to leave everything a few thou up and finish later. I think it's a matter of confidence, so go which way you're comfortable with.

[DetroiTug]

Yes, a lot of times the casting will have a taper from one end to the other. What I use for that, instead of cutting all surfaces twice ( cause I usually don't much time), is an 1/8" 3mm thick strip of UHMW plastic. It will conform and hold irregular shapes. It's good too for when you want to stack multiple parts together to drill. It's typically only used between the front jaw and the work.

-Ron