ghetto 4 rotor build
Jeff looks great!
Just one quick question/comment/criticism (hopefully seen as helpful)
You said the tension bolts are just steel rod stock? Are you talking about 01 tool steel stock? Or just plain old 1018, 4140?
If they are any of the lower carbon content steels you might have a serious issue in days ahead when you try and pre-load the bolts. The problem that hit me, (i thought of this during a 3 hour drive up to NH to see my car), was that a bolt that long will have some serious stretch in it when torqued down. This by itself will not be a problem, since you will have all those nice big engine mounts on either side, but what could happen is that one end of the bolt could anchor itself and when you start twisting the nut on and torquing down. You end up twisting the length of the rod, thus adding a shear stress to the anticipated tensile stress in the shaft. This would then set up a situation where you have differring pre-loads in each shaft which would ultimately lead to leaking and banging collective heads against walls.
What I was thinking that might help, even if this is nice dense 01 tool steel, is to do some minor heat treating on the rods so that they are a little stiffer... quench, temper, and anneal (annealing would only be needed if you wanted to get some ductility back into the rods, if you were worried about these things snapping from the loads).. what's really important is that quench is done correctly or all the rods will be U shaped.
Anywho... I'm not saying that i'm right and you're wrong. I'm just interested in seeing this beasty put out it's 500-600 hp (easily) for many years to come!
Please let me know what you think.
Keep up the great work
Pete
Just one quick question/comment/criticism (hopefully seen as helpful)
You said the tension bolts are just steel rod stock? Are you talking about 01 tool steel stock? Or just plain old 1018, 4140?
If they are any of the lower carbon content steels you might have a serious issue in days ahead when you try and pre-load the bolts. The problem that hit me, (i thought of this during a 3 hour drive up to NH to see my car), was that a bolt that long will have some serious stretch in it when torqued down. This by itself will not be a problem, since you will have all those nice big engine mounts on either side, but what could happen is that one end of the bolt could anchor itself and when you start twisting the nut on and torquing down. You end up twisting the length of the rod, thus adding a shear stress to the anticipated tensile stress in the shaft. This would then set up a situation where you have differring pre-loads in each shaft which would ultimately lead to leaking and banging collective heads against walls.
What I was thinking that might help, even if this is nice dense 01 tool steel, is to do some minor heat treating on the rods so that they are a little stiffer... quench, temper, and anneal (annealing would only be needed if you wanted to get some ductility back into the rods, if you were worried about these things snapping from the loads).. what's really important is that quench is done correctly or all the rods will be U shaped.
Anywho... I'm not saying that i'm right and you're wrong. I'm just interested in seeing this beasty put out it's 500-600 hp (easily) for many years to come!
Please let me know what you think.
Keep up the great work
Pete
Thread Starter
Joined: Aug 2001
Posts: 15,725
Likes: 91
From: Near Seattle
swbtm, you're thinking like a Boeing engineer. I'm not saying it's good or bad, I'm just saying you're thinking like an engineer. I don't know what type of steel the the tension bolts are, but I know several other people have ordered these multi-rotor kits with the same tension bolts and they always work fine. I see no reason to fix something that ain't broke.
That's all I wanted to hear 
And what's wrong with being an engineer? We just over think everything... not a bad thing... we just end up not getting as much stuff done!
As long as people have previously used these bolts then you should be fine, I was assuming that you were in completely uncharted waters here.
Good Luck!
And what's wrong with being an engineer? We just over think everything... not a bad thing... we just end up not getting as much stuff done!
As long as people have previously used these bolts then you should be fine, I was assuming that you were in completely uncharted waters here.
Good Luck!
Wow! I don't think I've ever seen you post anything this cool on mazdarepu.com. Then again, I haven't been there for a while myself. Looks like you are moving along at a good pace. Keep up the good work!!!
Junior Member
Joined: May 2008
Posts: 32
Likes: 0
From: Grantsville Wv
Omg I was thinkin the same.. Jef Is the Man get it done ,patten the e shaft design sell it to a chinese company they can mass produce it and I can make one cheep and you'll be rich we'll all be happy
There are plenty of machine shops here in the US that could make what you need plus you'd be able to keep an eye on quality control. China has no system of standards for their metals and is just out to make a quick buck by any means necessary.
Last edited by VincenzoL; May 27, 2008 at 11:58 AM.
hey jeff frist thanks for the pm's you sent me.
i figure you posted this already but could you answer this.
say i have two 12a motors that i could reuse to make a 4 rotor.
what else would i need to buy i know i would need the e-shaft.
i figure you posted this already but could you answer this.
say i have two 12a motors that i could reuse to make a 4 rotor.
what else would i need to buy i know i would need the e-shaft.
Wrkn Toyota, Rootn Wankel
Joined: Sep 2007
Posts: 1,642
Likes: 1
From: "Haystack" Hayward, CA
Cheap in quality would be more like it. Do yourself a favor and stay away from the Chinese goods.
There are plenty of machine shops here in the US that could make what you need plus you'd be able to keep an eye on quality control. China has no system of standards for their metals and is just out to make a quick buck by any means necessary.
There are plenty of machine shops here in the US that could make what you need plus you'd be able to keep an eye on quality control. China has no system of standards for their metals and is just out to make a quick buck by any means necessary.
Full Member
Joined: Jan 2007
Posts: 94
Likes: 6
From: Abbotsford
Seeing this thing will be interesting for sure.
Do you have a total price list for this? All said and done, this could bring powerful engines to the masses, as much as there is a mass for rotary enthusiasts.
Do you have a total price list for this? All said and done, this could bring powerful engines to the masses, as much as there is a mass for rotary enthusiasts.
Joined: Jun 2008
Posts: 8,376
Likes: 28
From: Chino Hills, CA
It's nice to know there's a project somewhere that is taking longer than my post-storage resurrection... heheh.
Great stuff, dying to see/hear how this turns out. Would love to do this kind of stuff, but it's beyond my logistics capability & probably "above my pay grade." No space, & not enough money lying around.
Great stuff, dying to see/hear how this turns out. Would love to do this kind of stuff, but it's beyond my logistics capability & probably "above my pay grade." No space, & not enough money lying around.
Thread Starter
Joined: Aug 2001
Posts: 15,725
Likes: 91
From: Near Seattle
You know the funny part is I could sell my 20B for $4000 and this would leave me enough to get started on a 4 rotor project of my own. The one featured in this thread is for somebody else. Imagine two 4 rotor projects running simultaneously.
Anyone want a 20B? It ran with an untuned standalone ECU in the GLC. Had too much power for the chassis.
Anyone want a 20B? It ran with an untuned standalone ECU in the GLC. Had too much power for the chassis.
