Search found 894 matches

by barts
Thu Jan 17, 2019 7:45 am
Forum: Technical - Engines and Boilers
Topic: Axial Thrust & Engine Bearings
Replies: 3
Views: 979

Re: Axial Thrust & Engine Bearings

For our steam boats, rule of thumb is that a pillow block bearing will handle any thrust loads from a prop that fits on that diameter shaft.

Engines w/ journal bearings w/o integral thrust bearings (or pillow blocks :)) should have a pillow or flange bearing to handle the thrust.

- Bart
by barts
Thu Jan 17, 2019 2:57 am
Forum: Technical - non Engines and Boilers
Topic: Prop Step Up
Replies: 10
Views: 4265

Re: Prop Step Up

Otter has the same problems w/ her 2.5" x 2.5" single as the counterweights are too small; the old 2" x 2.5" single acting twin was much smoother at speed, of course. I went to a 16"x20" prop from her old 13" x 17" because the new engine ran away w/ the small prop, but at full throttle (180 psi) th...
by barts
Tue Jan 15, 2019 4:17 am
Forum: Technical - non Engines and Boilers
Topic: Prop Step Up
Replies: 10
Views: 4265

Re: Prop Step Up

It has been "Shake, Rattle and Roll" in my old hull above around 350 r.p.m. but the motor mounts were pretty much a trampoline. We'll see on the new hull. Otter has the same problems w/ her 2.5" x 2.5" single as the counterweights are too small; the old 2" x 2.5" single acting twin was much smoothe...
by barts
Mon Jan 14, 2019 5:41 am
Forum: Technical - non Engines and Boilers
Topic: Prop Step Up
Replies: 10
Views: 4265

Re: Prop Step Up

I wouldn't become too preoccupied with a high pitch prop. My opinion to go along with the good ones above, but I think its better to let the engine spin with shorter cutoff with nearly the same steam consumption. Trying to get a lot of torque out of a slow turning engine looks nice but results in v...
by barts
Mon Jan 14, 2019 4:26 am
Forum: General Steamboat stuff
Topic: Steamboat music
Replies: 5
Views: 3724

Re: Steamboat music

The Beach Boys - Steamboat from their Holland album:

https://www.youtube.com/watch?v=2HPHuhAIPuU
by barts
Sun Jan 13, 2019 9:21 pm
Forum: Technical - non Engines and Boilers
Topic: Prop Step Up
Replies: 10
Views: 4265

Re: Prop Step Up

If I was to do it I would look carefully at a toothed belt. Mostly for the silence. And corrosion resistance. For smaller engines this would work really well. For bigger ones, the size belt + pulleys needed becomes problematic With V-belts it is sometimes necessary to use more than one belt to hand...
by barts
Sun Jan 06, 2019 8:32 pm
Forum: Technical - Engines and Boilers
Topic: Crank-shaft centre-line
Replies: 7
Views: 1766

Re: Crank-shaft centre-line

Well, first order concern is lining up the prop shaft and other things (pumps) driven by the engine, so that usually takes precedence. Otherwise, there's a side-to-side vibration caused by the crankshaft counterweights (unless you have a counter-rotating balance set up ), so keeping the center-line ...
by barts
Sun Jan 06, 2019 8:11 pm
Forum: Technical - Engines and Boilers
Topic: Condensing Circuit Logic
Replies: 17
Views: 3441

Re: Condensing Circuit Logic

The primary reason to keep the hotwell temperatures high in larger plants is to reduce dissolved oxygen, which is bad for boilers. Subcooling the condensate is inevitable with our small plants running at varying power levels, and given the fact that we're going to shut down soon anyway makes the dis...
by barts
Thu Nov 01, 2018 2:02 am
Forum: Technical - Engines and Boilers
Topic: Cylinder head gasket material ?
Replies: 7
Views: 2175

Re: Cylinder head gasket material ?

Assuming you're using normal hobby steam pressures and temperatures: For reasonably flat surfaces, hi temp RTV works like a charm, esp. if you have a small groove in one of the mating surfaces. You can also use gasket material for automotive purposes - it seems to work fine in my experience. If you ...
by barts
Sat Oct 20, 2018 5:04 am
Forum: Technical - non Engines and Boilers
Topic: Prop shaft diameter ?
Replies: 9
Views: 3306

Re: Prop shaft diameter ?

As you might expect, there is lots of detail about this in boat design books. One handy method is shaft diameter for Aqualoy or Monel should be 1/17.5 3 bladed prop diameter... so if you're using a 14" diameter prop, a 3/4" shaft would be a bit marginal. If you have a Tobin bronze shaft, the divisor...