[itsme]

Hi Nick,

I'll start a new thread for the engine that I am busy building. I'm just having some trouble with the lathe at the moment. I thought the start capacitor had gone on the motor, so I've waited 3 days for a new one in the post. I got it this morning, but it turns out that the capacitor wasn't the problem - it is the actual motor. I now need to sort this out, otherwise there will be no engine to post pictures of at all.

Regards
Warren

[MIKE JEFFERS]

stick at it warren, and lets see those photos
mike

[ramaeronaut]

Add me as a new friend! i have no cnc machines! but i have lot of passion to build a new wankel engine by own! so pls help me with current ideas! since past quories were happened in 2005!

Dream to fly! n Define Gravity!

[ajl6549]

The only other part that I'm a bit weary of, is the internal gear that's used to phase the rotor. I've never made any gears, yet alone an internal gear. Sadly, no one seems to make these things in the right sizes, so off-the-shelf parts are out. That's the next big challenge!!!

Regards
Warren

We make gears here where I work (Wi. USA.). If possible send a print, maybe I can get one of my gear shaper buddy's to do it ???

[JRoque]

That's most nice of you, AJL. If you end up cutting the gear for Warren, post a pic here, if you please.

JR

[ajl6549]

The catch would be if we have the right cutter or not. We do, however, have a very large selection of them.

[ramaeronaut]

We make gears here where I work (Wi. USA.). If possible send a print, maybe I can get one of my gear shaper buddy's to do it ???

hi! yes i want to make one internal gears for designing a wankel engine ! but i am now in india! pls give some theoretical idea! i need 3:1 ratio gears! when the wankel Trapezium runs one time my crank should revolve three times! so do reply! bye!

[ajl6549]

Well as far as designing the gears...I'm not sure what is required. I don't know anything about "your" engine design. You would have to provide the print of what your want the gear to be (i.e. helical or spur, number of teeth, and all other typical gear data. Keep in mind that you need two gears (or one "gear set")... I think, if I remember correctly how a Wankel is designed. Anyway get me a print, including all pertenant gear data, of your gear and I'll see what I can do.

[devincox]

Well as far as designing the gears...I'm not sure what is required. I don't know anything about "your" engine design. You would have to provide the print of what your want the gear to be (i.e. helical or spur, number of teeth, and all other typical gear data. Keep in mind that you need two gears (or one "gear set")... I think, if I remember correctly how a Wankel is designed. Anyway get me a print, including all pertenant gear data, of your gear and I'll see what I can do.

copied from:
http://www.cnczone.com/forums/showpo...0&postcount=94

the internal gear is a 21 tooth, module 1 gear. The spur gear is a 14 tooth module 1 gear.


Devin

[itsme]

Hi there,

ajl6549, my personal little 'rotary program' has stopped for a while, so I won't be needing any gears any time soon. Thanks for the kind offer, though. I need to sort various things out before I attempt to build another engine, such as an improved grinding attachment.

ramaeronaut, if you read into some of the theory on Wankel engines, you will find that although the rotor only does one revolution for every three that the eccentric shaft does, the gear ratio is in fact 2:3 - not 1:3.

Regards
Warren

[ajl6549]

copied from:
http://www.cnczone.com/forums/showpo...0&postcount=94

the internal gear is a 21 tooth, module 1 gear. The spur gear is a 14 tooth module 1 gear.


Devin

Explain "module 1 gear". I'm not familar with that term. Is that like a class of gear?

[jwstolk]

Explain "module 1 gear". I'm not familar with that term. Is that like a class of gear?

http://www.google.com/search?q=module+1+gears :-)

first result:
If gears are metric: To translate metric module numbers into US nomenclature, use the following equation: m = D/N=1/P where m is the module number, D is the pitch diameter, N is the number of teeth and P is diametral pitch. Module 1 gears are roughly approximate to a diametral pitch of 24 (exact is 25.4). However, mod 1 gears will NOT work with 24 diametral pitch gears or racks.

[ajl6549]

We don't have any shaper cutters for a MOD 1. I talked with our gear guru. We can cut it though with the right cutter.

[jwstolk]

(note: I'm not involved in this, just a curious bystander)

I don't think the exact teeth-pitch matters that much as the builder will be making the matching inner gear himself as well. From what i understood from google, MOD 1 = 25.4 TPI so a 24 TPI gear is very similar, but the you can't mix the two types in a single gear pair.
he posted an image a while ago:
http://www.cnczone.com/forums/attach...6&d=1124226680

[JRoque]

Hey Warren, I got great results when I ground my spindle by attaching the grinder to the lathe's toolpost. I made up a quick fixture out of a piece of aluminum and it worked well. You can then move the grinder with the lathe's knobs. All is well except, of course, you can't move up and down... but that can be solved with a little planning and moving stuff around.

JR

[Ken McKenzie]

Warren


The stationary gear is in fact a rack. It is a circular toothed bar that engages with a gear one third larger that rolls around it.

In one e-shaft revolution of the Mazda rotary engine only 34 of the 51 internal gear teeth in the rotor engage with the stationary circular toothed bar. The rotor in this instant is compelled to lose one third of a revolution.

In three revolutions of the e-shaft The center of the rotor is compelled to make three revolutions with the e-shaft lobe, At the same time the triangular rotor shape turns once counter clockwise to the e-shaft.

We find the subject has two view points that are correct but have different solutions.

When reference is taken from the e-shaft lobe we find a 3 to 1 gear ratio.

When reference is taken from the stationary engine we find a 2 to 3 gear ratio.

When reference is taken from the appearance of the action of the engine the rotor appears to turn clockwise once for every three e-shaft revolutions.

The Wankel rotary engine appears to have both a 2 to 3 gear ratio and a 3 to 1 gear ratio

Cheers

Ken

[RotaryNut]

Hi Warren
Any news about Wankel mk.II?

I just read thru all 18 pages, got a sore butt, square eyes and a stiff neck!
Damned impressed by your work and how rapidly you did it.


Have always dreamt of doing something like this myself.
Did a few CAD scratchings a few years ago, but only now got a mill and lathe.
Will be some time untill I'm able to make something like this tho, if ever!, only time will tell......

Would be great to hear latest news, if any.
Would be a shame if all that hard work has gone nowhere tho!

Simo

[itsme]

Hi Simo,

Wankel mkII certainly hasn't been forgotton, but having said that, it'll be some time before there is anything to show for it.

I need to make some more machine modifications and hopefully there should be a new CNC project in the not-too-distant future too, which will help a lot.

When there is something to show, I'll post it here, but I doubt very much that there will be anything in the next few months.

Regards
Warren

[flesvik]

Hi Warren.
i am new on this forum.
I just read thru all 22 pages and find it very interesting although it took “some” time. It’s not many that make wankel engines from scratch. You shod finish it especially because it is such a rear engine project.

I was thinking of how it would be to cast it instead of machining it (for those who don’t have a strong enough CNC machine). What I was thinking of was to machining a foam block and then use lost foam casting to cast the rotor and housing from aluminum. Because the aluminum is softer than steel I would make side seals and oil seals (I would be using oil cooling for the rotor and water cooling for the housing).
As you maybe see I want to make a bigger engine than you.

What do you think of this idea? Would the housing survive if it was made of aluminum? The side plates could be made from steel though.
And finally how did you make the Eccentric Shaft? (I mean how you made the lobe on it).

Thank you for a great thread by the way.

[Eson]

Casting aluminium is not very suited for precision models which the wankel requires. Because of the high thermal expansion ratio it would be very difficult to cast it to the right tolerances.

But the real mazda wankel rotor house is made of an aluminium alloy with a coating inside for endurence. Those houses are first rough casted and then machined to the right tolerances.