Kearsarge Windlass Engines

[Kim]

Nice looking set of little crank arms, Chris! 

Kim

[cnr6400]

  Industrial age, space age ? I guess we must be in the link age now! 

[crueby]

Industrial age, space age ? I guess we must be in the link age now! 

Or cranky old age?   

[crueby]

Nice looking set of little crank arms, Chris! 

Kim

Thanks Kim!

[crueby]

After a nice long lunch out with some friends, got the crank ends drilled for the pins, and started assembling. The aft end and the control arm went in fine...

and thats when the wheel fell off the shopping cart! The bow end crank went on, then tested the movement of the reverse links to check alignments. All aligned, but the bow end link is hitting the base of the crank!   

Turns out that I made the two links identical, tabs on same side of each. I SHOULD have made them symmetric, with one having the tabs offset to the other side than the first one. That way, the outer eccentrics of each pair would work together for one direction, and the inner ones would work together for the other direction. That is, with the outer ones being attached to the links at the end closest to the control rod, so that the tabs would overlap outside the ends of the control rod. As you can see in the photo above, the tabs stick down farther from the cross rod. The other link should have been mirror of that with the tabs hanging down the far end of the cross rod.

Elf-pucky!   
Here is a look at one of the links, showing how the tabs stick out the side to support the pivots:

So, the solution is one of two things: remake one of the reverse links, or modify the existing one. I think I'll modify the existing one. All I need to do is cut off the existing tabs, silver solder blocks onto the other side, and shape in new tabs. That way, I can be sure that the link will still match the first one for arc and spacing, and the slider is known to fit smoothliy. Making a whole new one could involve making a new slider and changing more on the valve rod lengths. I will still have to retime the two eccentrics at that end of the engine, since they will be swapping directions.

Again, this fix should only take a day. Starting to think this engine doesn't want to be finished and left on a shelf, it wants more attention every day!   

[cnr6400]

  oopsie! sorry all 4025 of us missed the problem and didn't let you know.  Sounds like the fix is not too bad, anyway. 

[crueby]

oopsie! sorry all 4025 of us missed the problem and didn't let you know.  Sounds like the fix is not too bad, anyway. 

New blocks are already soldered and and cooling as I type!  Shouldn't take long at all to fix this.   

[Kim]

Bummer on the symmetry issue there, Chris.     I know how that feels.  I still do it and I'm following a well documented set of plans! You're off in uncharted territory, making unique, never-before-modeled engines.  This kind of thing is bound to crop up from time to time.  But that doesn't make it feel any better, I'm sure.

Kim

[Casting Iron]

I just browsed through all 75 pages of this build.
I could feel myself aging, but it was well worth the effort.

Some really nice 3D modeling, 3D printing, fabrication, and machining work.
Most impressive.

.

[crueby]

Thanks guys! Great to have you along for the ride!

[crueby]

This morning got the milling/filing done on the new tabs on the bow end reverse link. If you compare this photo to the one yesterday, you can see that the tabs are on the opposite sides now, where they belong.


It has been assembled onto the eccentric arms, and everything clears now.      One last thing to get caught up to where it was is to retime the eccentrics at that end, since now the two eccentrics go to opposite ends of the link than they did before. I can mark where they are now, and use those marks to move them to the new position, so the retiming should go quickly. Once it is running again, next time I can make the control arms that run from the cranks to the ends of the reverse links...

[Kim]

A great recovery, Chris! 

Kim

[crueby]

Thanks  Kim!  After lunch and some errands I  marked where the bow eccentric centers were and swapped them, put pressure to the engine, and it took right off in both directions, pressure was so low it barely registered on the compressor gauge.   




So, next time I'll  make the connector  links, then on to the handwheel assembly.

[cnr6400]

  Good to hear things worked out with the revisions. 

[crueby]

Thanks  CNR,  it  all went very easy, and I  think the engine is runnin even better now, either loosening up or the new timing hit a sweeter spot!