[Ken McKenzie]

I personally Have did not know that there was such a thing as a VB program until your post.

I have had instructions on how to draw the housing in my site for about three years.

Bernard Maillard the designer of the Wankel engine shows the basics of the art in his 1943 patent.

Take the information I gave and instead of rotating the lines 2 degrees clockwise rotate the lines two degrees counter clock wise.

You will end up with the accurate art that has been depicted for many years to have the ability to drill square holes.

Cheers

Ken McKenzie

[Ken McKenzie]

Kiwi

When I said the short answer is no. I thought you were asking if the lines were necessary. The art can be drawn with just the dots. It is more difficult to show the process without the lines.

Take care

Ken McKenzie

[Ken McKenzie]

Kiwi
You should change the program you made to draw the complete housing without the lines. only use the dots.

Or in the alternative call it one quarter of a wankel housing.

Thanks

Ken McKenzie

[Kiwi]

Renamed, modified and spelt Wankel correctly.

[One of Many]

Thanks for the clarification Ken,

I take it that the space in the line adds little but reader confusion, if it could be done without? I'd like to try that in Solidworks and possibly an animation if I can find the time.

Great that this could be proven, but it does make me wonder how other rotary OEM's could be so far off in their profiles.

DC

[Ken_Shea]

have had instructions on how to draw the housing in my site for about three years.
Ken McKenzie,
I had visited your site a long time ago and it had a number of links to different pages, now all I can see is the home page, Am I overlooking the links ?

Thanks
Ken

[Ken McKenzie]

DC

Sorry I am so old.

In my day if a person wanted to understand something he or she would get out a pencil a ruler and follow the directions.

I failed to say from left to right in my first instructions but it was not necessary as Kiwi succeeded in drawing the quarter housing drawing right to left following the same instructions.

The object was to draw a quarter housing, the space and the dot provided the separation with the dots providing the end result.

If you have a Mazda housiong available draw a housing using the same directions except make the circle 1.182 inches and make the radius 4.1 inches.

Place this drawing on the Mazda housing and you will see the difference in the geometry.

I made a machine to refinish Mazda housings using their gears and eccentric shaft. This machine clearly demonstrated failure of their housing to be precision.

The housing profile is basically the same since 1969. But I found small differences in two housings in the same engine. (I modified the refinish machine to be adjustable.)

If you want to make a program to draw housings it should provide for alterations of the diameter of the desired eccentric, and for a different radius of the rotor.

Cheers

Ken McKenzie

[Ken McKenzie]

Ken Shea

I was providing cutting edge technology on my web site that was misunderstood.

Nothing is more offensive than good advice, I got tired of offending.

Take care

Ken McKenzie

[One of Many]

Ken,

It's not that you are old. It has more to do with me not reading more into what I see as instructions that leaves too little for interpretation. Possibly the pitfalls of AutoCAD as everything has a dimension to keep things associative within the drawing. The literal effect of the line being 2.75 long with a dot after a .250 space, or as mentioned no real need for the space in a CAD drawing?

I drew the 3" lines exactly as Kiwi's VB was done. No space, but thought it was incorrect trying to visualize where I went wrong with the missing space dimension.

Now if I could have created a DXF file from pencil and paper sketches, I doubt I would have done so well with the precision. I've come to trust my PC DWG's more than my chicken scratchn's

Over the long run of the apex seals having minimal movement. I wonder if there will be any issues of too much wear in a small area or low movement, running somewhat dry, filling with carbon packing behind or along the seals, thereby stopping the seal action earlier rather than later. I just can't help thinking maybe (with Mazda)there was some non-precision thrown in there on purpose to cover other "known issues" to get the seals past the warranty period .

DC

[Ken McKenzie]

Over the long run of the apex seals having minimal movement. I wonder if there will be any issues of too much wear in a small area or low movement, running somewhat dry, filling with carbon packing behind or along the seals, thereby stopping the seal action earlier rather than later. I just can't help thinking maybe (with Mazda)there was some non-precision thrown in there on purpose to cover other "known issues" to get the seals past the warranty period .

DC[/QUOTE]

DC

Actually some Mazda Housings are more precision than others.

The housings that are less precision have more leverage in their strokes so therefore are more powerful but will not last as long.

The sealing in the rotary engine requires the compression and combustion pressures to be applied the underside of the seals. (Apex seals, side seals and corner seals) Movement causes the rubbing surfaces to wear and tolerances to deminish.

Actually reciprocating piston engine would work very poor if it only had to rely on the spring in the rings to seal it. It also utilizes the combustion pressures.

I believe there was too much trust put in Professor Othmar Baier of the University of Stuttgart who discovered that the housing was a epitrochoid.

When the Mazda engineere know how the housing is made and it is a reasonable assumption based on a simple drawing, why would they question the knowledge?

Did you try the triangle in square design mentioned in a earlier post?

Thanks for your thoughtful reply

Ken McKenzie

[Kiwi]

Ken Mc
Quote#1 >Draw a horizontal line with a space and a point ending exactly at three inches starting at the 44 minute position, then rotate this line two degrees clockwise.<

My interpretation of this was to draw a line three inches long with a point at the end. To me it is not clear where the space should go.
I drew this line from left to right and then rotated on the point as I considered this identified the pivot point as the instruction does not make this clear and why would you draw a horizontal line unless it was necessary to establish this point. I now see the line just comes off the inner circle at a particular angle.
I do accept drawing the horizontal line may have made the drawing easier to describe if the space and pivot position was made clearer.
This is how I found the exercise, but I am also in my 60's which may explain quite a bit.

[Ken_Shea]

Nothing is more offensive than good advice, I got tired of offending.

Unfortunate, but I do understand Ken.

[Ken McKenzie]

INSTRUCTIONS FOR MAKING A WANKEL ENGINE

The non precision housing is insignificant when you take the time to understand how the engine should be made.

Here is a short list of additional problems.

I believe the people working on developing the Wankel engine:

Do not know how to make a constant velocity gear system.

Do not know how to make the rotor.

Do not know how to cool the rotor,

Do not know how to make a direct connection between the e-shaft and the rotor therefore the rotor action is spongy. Therefore the timing system is faulty.

Do not know the sealing principles that take place in the sealing grid. Subsequently the sealing system can be simplified and improved

Do not know how to port the engine, sequential to them not knowing how to make the rotor.

Do not know ideal placement for the sparkplug.

I will attempt to explain the above and the solutions in the near future

Ken McKenzie

[Ken_Shea]

Looking forward to it Ken.

Thanks

[itsme]

Hi there,

I'm surprised we have any running wankel engines at all, seeing that the people making them apparently don't know how to make most of the major engine components. Ken, I don't mean to be rude, but why have we not seen one of your own engines outperforming these 'inferior' engines?

I'm not trying to cause trouble here, but I think more credit is due to all the people that have developed the wankel engine into what we have today - I really don't think it is as bad as Ken makes it out to be.

Regards
Warren

[Kiwi]

A job has just come into my shop. The customer has had .005" surface ground off one of the end plates. He requires me to deepen the two grooves this same amount on my CNC mill. I haven't seen either of the seals and I question wether this depth is critical?
Also note that the inner groove is wider than the outer and question if this width is critical?
Any advice welcome.

[Eson]

Ive tried sevral times to make a wankel in CAD but failed evrytime. Now when i saw this i just had to try again. Hours and hours later of failures i finally succeeded!
Now i can finally begin to experiment with the wankel-design and maybe accually make one later on!
I used 45(46 acually..)minutes and its accurate to about 0.00001mm on the apexes 360 around the house walls, according to the CAD program.

Edit: Thumbnails.

[Ken_Shea]

Looks good Eson,

Thumbnails are automatically created when you upload the picture, this is done when replying to a post and scrolling down below the reply message box where it says "Manage Attachments"

I always optimize the picture first in my drawing program, thus reducing the file size. Saves bandwidth for the CNCzone and up/down load time for people still on dial up.

Ken

[Ken McKenzie]

CONSTANT VELOCITY GEAR SYSTEM

If you are in love with your understanding of the principles for making gears do yourself a favor and skip this post.

Visulize two one quarter inch deep one inch diameter metal disks and place them one quarter inch apart. Push or pull a ¼” X ¼” piece of key stock between them and you should note that they turn with two pitch circles that are on the outside of each disk.

I am going to now give directions for making a spur gear and an internal gear that would work in the Wankel engine design. The teeth will have the exact same effect as the piece of key stock. Therefore there will be two pitch circles and both gears will produce constant velocity.

BOX GEARS

Start three inches down from the center of the page and make a center point.

Make a diagonal ½” square box and move the left hand point one inch horizontal to the right of the center point.

Rotate the drawing 18 degrees and repeat the process 19 times. You will end up with 20 ½ “ boxes separated by 18 degrees all one inch from center.

Inside of this assembly you will find a white (if your paper is white) two inch ID spur gear.

Take a new sheet of paper and start four inches down from the center of the page.

Make a diagonal ½” square box and move the left hand point one and one half inches horizontal to the right of the center point.

Rotate the drawing 12 degrees and repeat the process 29 times. You will end up with 30 ½ “ boxes separated by 12 degrees all one and one half inches from center.

Paint all the boxes black the inner circle will show black gear teeth that are the perfect match for the white spur gear.

Welcome to the world of CV Box gears. The spur gears also mesh with constant velocity .

Ken McKenzie.

. .

[Ken McKenzie]

Kiwi
The end plate you are refering to was facrory hardened and .005" would have removed it.

The inner ring is a composite rubber type ring that can withstand the combustion pressures and the outside ring is rubber made to hold water.

If you don't remove the .005" from the grove the material will compress that much and probably provide as good if not better seal.

Cheers

Ken McKenzie