Author Topic: Modified Kimble engine  (Read 5491 times)

Offline wdeputy

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Re: Modified Kimble engine
« Reply #15 on: August 25, 2014, 04:52:13 AM »
The eccentric noted above was designed as a flat strap on the original plans.  The connecting rod was made likewise.  They were bent to align with the valve arm and vane arm and had pins on the ends for the pivots.  Placing the eccentric outside the support and in line with the valve arm meant that the connecting rod would be moved further away as well.  My idea was to offset the end of the rod at the vane arm.  The main portion of the rod was cut to length and a small piece soldered to one end.  This would form the offset fork at the arm end.  Both pivot holes were drilled and reamed to size.  The fork was formed in the mill after narrowing the rod slightly.  I left the crank end of the rod at the original size of the brass for appearance sake.  This just shows in one of the photos.  A groove was made in the outside face of the rod, again for appearance.  The bearings were made of brass, squared with the spin index and slotted to fit the columns.  They were drilled slightly undersized to be reamed at installation.  They were parted off and set aside.

Offline wdeputy

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Re: Modified Kimble engine
« Reply #16 on: August 25, 2014, 04:57:57 AM »
The columns were squared and then the slots were cut for the bearings.  While they were clamped together, the holes for the retainers were drilled and tapped.  Excess material was removed at the band saw and both columns were mounted in the rotary table.  The large radius was then cut and the edges trued.  Both pieces were kept together for all operations to keep them the same.

Offline wdeputy

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Re: Modified Kimble engine
« Reply #17 on: August 25, 2014, 05:10:04 AM »
The base was laid out and drilled for all the mounting holes.  When the columns were bolted in place the crank bearings were reamed.  I used adjustable parallels to support the columns while reaming.  Several small fasteners needed to be made for the crank and eccentric pivots.
OK, gotta fess up here.  My plan "B" of using nylon rods to seal the vane proved to be just as worse as the original plan.  When I got to this point and made a trial assembly, it leaked way too much.  Plan "C" was to try using carbon coated string.  A larger piece was unwound and the separated parts were just the right size to fit the grooves in the vane.  This worked just like I had planned from the start.  The string formed nice tight corners and did not increase the friction against the sides.  I don't know how they sealed the prototype but it must have been a real pain.
The photo below is the top of the body at trial assembly and shows the solder joints before painting.  Then there is the completed engine.

Online Jo

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Re: Modified Kimble engine
« Reply #18 on: August 25, 2014, 07:20:34 AM »
I do like you engine... I had to go and download the plans from John-Tom's site only to find they are in the Elmer's engine book  :facepalm:

Those little curvy modifications you have done to the original "square" design does make it look so much nicer  8)

Jo
Enjoyment is more important than achievement.

Offline Saxalby

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Re: Modified Kimble engine
« Reply #19 on: August 25, 2014, 11:07:33 AM »
Nice engine.
Have looked on the John-Tom site for the plans but cant seem to find them.
Can anyone give a direct link to the plans.

Regards
Barry
Cum omnibus deficiat ledo eam cum magnum malleo

Offline Saxalby

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Re: Modified Kimble engine
« Reply #20 on: August 25, 2014, 04:58:23 PM »
Found the plans
Cum omnibus deficiat ledo eam cum magnum malleo

Offline wdeputy

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Re: Modified Kimble engine
« Reply #21 on: August 26, 2014, 07:44:25 AM »
Thanks for the comments.  With any luck this has given someone an idea for their own projects.
Walt

Offline Saxalby

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Re: Modified Kimble engine
« Reply #22 on: August 26, 2014, 11:49:24 AM »
Certainly has. Just starting to sort out various raw materials to make a start.
Cum omnibus deficiat ledo eam cum magnum malleo