Author Topic: Dieter Hartmann-Wirthwein patent engine  (Read 42580 times)

Offline Johnmcc69

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #30 on: March 15, 2014, 12:16:39 AM »
Great method for creating the washers Gail. That's some good thinking!

 John

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #31 on: March 15, 2014, 12:31:22 AM »
Mosey,
No apologies necessary.  I was not clear in my writing. Typical forum syndrome of I knew what I thinking so why didn't everyone else.

John,
Not my idea but I have been using it for over 20 years. I would give credit to the source but don't remember where I got it from.

Gail in NM
I would like to be the kind of person my dog thinks I am.

Offline Brian Rupnow

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #32 on: March 15, 2014, 12:35:11 AM »
Gail--Re opossums as discussed in your previous engine build. Strangest thing happened this afternoon. The room that has my television in it also has sliding glass doors that look out on the bird feeder. Wife was watching telly just at dusk when she called me from the other room to "Come Quick and see the funny looking animal".---It was an opossum!!! This quickly lead to an internet session, and By Golly---They have arrived in Ontario. Seems that every year they extend their habitat northwards. I had never seen a real one before.---Brian

Offline b.lindsey

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #33 on: March 15, 2014, 12:46:03 AM »
Real cute critters aren't they Brian.... :ROFL:  A gift from your neighbors to the south!!

Bill

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #34 on: March 15, 2014, 10:51:02 PM »
Brian,
I have never seen one in NM.  Too dry for them I think.  There are a few rumored to be in southern NM mountains however.
Gail in NM
I would like to be the kind of person my dog thinks I am.

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #35 on: March 15, 2014, 11:07:08 PM »
More toy building. 
I have drawn the linkage up several times. I keep vacillating between what I can build and what I can assemble.  I finally have decided on a course of action.  All the alternatives should work once assembled. Then we get to see what goes bump in the night with the parts.

To satisfy both requirements I decided to put yokes in the pistons to carry the wrist pins and held in place with a screw into the yoke through the crown of the piston.  I have done this before on steam and Stirling engines but never on an IC engine although I have seen several examples of model aircraft engines from the 1940's that were built thlis way.

One additional advantage of this is the piston can be mounted on a stub mandrel with a screw for final finishing.  That way I don't have to make up a more complex expanding mandrel for lapping the piston. Also, since no wrist pins go through the piston wall I can make the piston wall thinner thus giving me more room for the goodies in the piston and since there is no hole to get in the way I have more freedom in positioning the oil distribution groove and the shallow ring grooves.

Gail in NM
I would like to be the kind of person my dog thinks I am.

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #36 on: March 15, 2014, 11:27:03 PM »
Getting started with the simpler yoke that is used in the outer cylinders.
A piece of 0.281 brass rod was surfaced on two sides to form a "Double D" shape with the sides 0.172 apart and finished to length.
Then the wrist pin hole was drilled and reamed 0.094 in the mill.

The part was then moved to the lathe and a hole was drilled and counter sunk so the part would sit flat on the inside of the piston crown.  It was drilled into the wrist pin hole.





And finally tapped 2-56 to take the mounting screw.


Gail in NM

I would like to be the kind of person my dog thinks I am.

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #37 on: March 16, 2014, 12:28:22 AM »
The yokes for the inside cylinders are a bit more challenging. In finished form they have two intersecting wrist pins of 0.094 diameter.  While the other yokes were made of brass these yokes are made of steel as two stub wrist pins are machined as a part of the yoke. Steel is needed both for strength and for a bearing surface for the small connecting rods.

I started by blanking out the yoke on the lathe using 3/8 diameter 1144 steel.




Then the bar was transferred to a spin index on the mill where the sides were milled off and the pins rough turned using CNC.  As the pins will be turned to finish size later the pins could be roughed out to 0.100 square on a manual mill and fitted into a 9/64 collet or an ER style collet on the lathe for turning later.


While still on the mill, the hole for the other wrist pin is drilled and reamed 0.094.


Then back to the lathe where the yoke is parted off long and then reversed into a 0.218 collet and finished to length. The blank was turned long to allow the end mill room for roughing out the stub wrist pins.




Finally one of the stub wrist pins was pun into a 0.125 collet and the exposed end finish turned and polished to 0.094 diameter. Then it was reversed into a 0.094 collet holding onto the just finished pin and the other end finish turned and polished.


Gail in NM
I would like to be the kind of person my dog thinks I am.

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #38 on: March 16, 2014, 12:49:12 AM »
After the yokes I needed an easy part so I made the through wrist pins.  They are just 0.094 12L14 steel polished and cut to an accurate 0.375 length with the ends faced off square and burrs removed.
Gail in NM

I would like to be the kind of person my dog thinks I am.

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #39 on: March 16, 2014, 12:56:59 AM »
And for the last post for today a family photo of the above parts.  For my non USA friends that US penny is 19 mm diameter.
Now I have to blank some material for the bell cranks and then do some decision making about the cylinder head design to get the push rods by it and an intake and exhaust port in place.  I need to do that before I can finish the frame.  And while I am thinking I need to make the short connecting rods.
Gail in NM

I would like to be the kind of person my dog thinks I am.

Offline Don1966

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #40 on: March 16, 2014, 01:28:36 AM »
Gee Gail! I missed a bunch of post somehow but have just caught up. Seems like you and Stan are leading the pack.  :lolb: Really though some nice work Gail and always a pleasure to follow along.

Don

Offline zeeprogrammer

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #41 on: March 16, 2014, 02:25:36 AM »
And for the last post for today a family photo of the above parts.  For my non USA friends that US penny is 19 mm diameter.

Good grief them's small parts. Nice work! Great photos too!!
Carl (aka Zee) Will sometimes respond to 'hey' but never 'hey you'.
"To work. To work."
Zee-Another Thread Trasher.

Online Kim

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #42 on: March 16, 2014, 02:58:05 AM »
Neat work Gail!  And as Zee said, SMALL!  You always work small, don't you?

I go off line for a few days and you just keep making progress.  Doesn't everyone get busy when I do? ;)

Kim

Offline GailinNM

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #43 on: March 17, 2014, 07:25:09 PM »
Thanks for the comments Don, Zee and Kim.
I spent much of my working life in industries where small was a requirement.  You had to get 12 pounds of "stuff" into a 5 pound bag because if you didn't the competition did.  And then the next year you needed 13 pounds in the same size bag.  Old habits die hard. Now my brain still has the same mind set butl the eyes and fingers don't always cooperate. But is good therapy to keep me going.  But I promise no more 1/16 inch bore and stroke steam engines like in the olden days.

I found a bust in my CAD drawings.  A stupid snap to the wrong place that then propagated to several more detail drawings.  It will take a couple of hours to clean them up.  I did get the cylinder heads detailed out enough that l could order material for them, which I did a few hours ago.  And, as they were not affected, I made the short connecting rods.

In the first photo you can see a 1/16 diameter spot in the middle each rod.  This is to identify them as being made of 6061 alumninum as the final ones will be made of 7075.  I only need 8 for the mock up blut of course I made extras to feed the swarf bunnies.

Here is the other side so you can see the three small tabs used to hold the part in place for the final finishing operations. They are 0.007 wide and 0.015 thick.  You can also see that I did not all the exit burrs from reaming off the parts on the right end. They are gone now.  Just have to clip the parts out with a pair of diagonal cutters and file off the bits of the tabs that are left.
Gail in NM


« Last Edit: March 17, 2014, 08:15:17 PM by GailinNM »
I would like to be the kind of person my dog thinks I am.

Offline Heffalump

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Re: Dieter Hartmann-Wirthwein patent engine
« Reply #44 on: March 18, 2014, 09:14:56 AM »
Great work gail I'm enjoying this

 

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