Ya' I know.... but I can only do what I have the capabilities
to do. This is not a serious project and no claims have been
made. I was more inspired by all the comments on how it
would never work. One thing though, it is a straight vane
rotor design, but the rotors are very aggressive and on top
of that I plan on them spinning upwards of 70,000. I will
probably use the delrin with an aluminum hub for the gears.
I thought about it today and I can test it with just rotor shafts
and no rotors in case anything goes wrong. I figure if it holds
together using a dremel for power and the intended pulley's
it should be OK. Would like to use an 1/8" wide cog belt.
Can anyone point me in that direction? Blower shaft is 5 mm.
About the straight cut gears, Man I hope they're loud!!

P.S. Wife wants a digital video camera for Christmas. Think Ill
go and by me..... I mean HER one and get some video of this
thing to post

Don't some of those mini rc copters use tiny cogs?

Anywho, the link below may be helpful, dunno. I didn't do the pdf. stuff. On dial-up, it takes to long.

http://fennerprecision.com/tooling.phtml

Looking at the first photo you posted above, I think it would work better if you swapped the rotors from side to side, assuming that is the front of the blower. The one on the right needs to rotate clockwise and the one on the left counter clockwise (after swapping them).

After my last post I have been thinking about this a lot and don't ever recall seeing a blower on a 2 stroke engine, is there a reason for this? I don't know, but I wish you all the success in the world. Does your company need a CAD designer?

<null>

That's actually the bottom. I have the plate and tube figured out
for the intake port. There was just nothing machined on the other
side for photo purposes. Blower on a 2 stroke.... novelty as far as
this particular project goes.

I was gonna' run it the other way.
I swear to GOD we have been drag race fans forever and have been
in the pits with blowers laying around plenty of times. We also figured out
the hard way why all the crew wears gas mask's when they fire up the
fuel cars in the pits. We were the ones on the ground who couldn't see
or breath while everyone else stood back away. It was the coolest thing!!

Is it that "design flaw" or him asking
if my company "NEEDS" a CAD designer. You know Im just kidding but you
can still kiss my ass. Listen and learn children. A big bite of humble pie is
good for you sometime. OK. Some splain' the efficiency of the mixture
running around the outside of the housing.

lubrication ?? in roots type blowers the edges of the rotors have a teflon strip to provide lubrication in yout design i dont think having the air go around the blower will actual do anything except loose pressure i think (but what do i know) that it would be best to let it exit through the center after its compressed

Take a look at this link, it has an animated bmp, you can see how the air travels around the outside.
Although these are not car blowers the operating principal is the same.

http://www.republicsales.com/roots.html

This is also how gear driven pumps work, like an oil pump, the fluid moves around the outside not through the gear mesh. When the teeth on the gears mesh there is no room for the fluid.
Raz,
The lubrication is for the gears driving the rotors. You are correct about the rotors having some type of coating to make a good seal with the case.

Lazershop, please keep posting pics of your progress.

Oh, Ill keep it posted. I told on myself because I just wanted
to keep it real. Any help is greatly appreciated, but it will always
be somewhat of a simplified design. I am totally willing to do a
complete redraw and use this one to sharpen pencils or
something.

May I ask why?

Raz, there is only one or two companies still running Teflon strips on the rotors. Every body else figured out that by closing the tolerances a wee bit between them, the strips were no longer needed and without the loss of efficiency. In fact, it improved efficiency over time. On the “old style” Teflon stripped SC’s, as the strips wore and were getting to the “need replacing” phase, the SC was doing its job half ass.

The strips aren’t for lubrication. They are to close the “gap” between the rotors. Another fact: The rotors never touch each other. The precision drive gears enable the rotors to be “timed” for zero contact.

PAINLESS, good job on the link and explanation.

New unit fresh off the mill. True blue "Roots" type blower. Did
me some learnin'. This one a six lobe design with much tighter
tolerances. Figured if I am doing it might as well make one
that will guarantee boost. Never mind the flash. Hasn't been
deburred yet or any second ops. This one is bigger also.
We'll call it.... a "1-.21". Hex on the end of the shaft is to
drive the gears. Hole on the back of the rotors is for a steel
shaft for the rear bearings. Rotors will be sanded, polished
and then anodized. After that the bearing race will be machined
just behind the hex. Figured the rear bearing plate is better off
being an integral part of the case. Made more sense. Also I
plan on doing more of a 50% underdrive. I learned that a Roots
becomes inefficient at super high RPM's

nice

wow is all I can say, they way I look at it, i'm wondering if it will work. There looks like there is a slight gap, the way i look at it, a good roots type canister is if you take a mechanical or electrical pencil sharpener apart, how the "blades" spiral like in roots super chargers. They have to be milled to like a .00001mm to work properly. Otherwise they won't work properly
cause its tiny all that tiny amount of air wouldn't be forced too well. just some of my 2 cents.

laser thats loks radical. when your done you gotta post pics of it. i wish i had your talent i would be making big bucks right now if i were you. btw what vechile are you planning on running this in?

Its not a pencil sharpener.

And it isn't worth that much.

What you speak of is known as a screw type blower. Different animal.

Don't some "street" (1:1 scale) blowers still use straight lobed rotors? Hampton's I think, and the small B&M's? Anyway, about the clearance, do you think the rotors are gonna get warm, and expand? That would take up some of it, and give a nice precise fit. But the case is gonna expand too... With the alcohol fuel flowing through it it probably won't get very warm though...Hmm, just thinking out loud here...If that sucker is spinnin' at 1/2 crank speed, that should be, what, up to around 15,000 R.P.M.? You oughta get SOMETHING commin' out as far as boost is concerned, aye??? Well, some volume anyway, but boost, who knows? Leakage and cavitation might be a problem...Hope it works man!!! My 27 1/2 cts. (inflation)

Oh? B&M's super charger is the screw type. I have never seen a super charger without the screws. The lightning, the T SC have the eaton one's and they have the screws, same thing with the Grand Prix's GTX's engine... I have never seen one without the screw design. ( just saw the hampton's post.. going to go look it up)....

Here we go again....

A true roots rotor has some (miner) helical (or twist) to the rotor.

The “pencil sharpener” example you gave is a screw type blower.

B&M makes both roots and screw type.

Straight rotor blowers have been around for years and usually have been for diesels with only two lobes on each rotor. But they are loud, really, really loud. The helical rotors helped cut down the noise but had little effect on the efficiency. I’m looking at six lobe rotors in those pics above and going “wow”.

well that explains it, the reason why alot of cars use the screw helix type is because they are daily driven. I mean I know they make the high whine. I looked up hampton and they all were on Dragsters and other high performance engines. I've never really hit the track and got to experience anything that has EXtrEME power.. my knowledge is all limited to street stuff.

Tis ok, you did what so many don't do......... Research.

If more and more people would find Google, there would be little reason for forums.

Thank goodness for laziness.

ya ya, I just based it off my knowledge... blah.. oh wells..

Let me say it slowly ...... I CANT MAKE A HELICAL ANYTHING WITH
WHAT I HAVE IN MY SHOP. I learned that the difference between the
roots type and the screw type is not only the lobe design and the way it
looks, but the screw blower is a compressor and the roots is a pump. They
also turn different directions. Ever notice how far forward a screw blower
sits on a motor? It compresses air from one end to the other, inside the
housing. The roots type "moves" air from top to bottom. Anyone know
how hard it is to make rotors less than half the size of a dime? Jeeze.
Billyman saw my thinking as far as design. That will be a total of twelve
lobes spinning. If nothing else, that mixture will be good and atomized
before it hits my ported and polished motor. I base my findings and my
progressive lack of ignorance on this website...

http://www.grapeaperacing.com/GrapeA...supertypes.cfm.

It is very informative. Now, as far as blower size goes, it was a guess that
was dictated by available room and scale appearance. So lets not go there.

One more thing...... If anyone from RB Innovations has caught wind (pun intended)
of any of this, I have no intentions or am implying any slander or malice against
your product. This is a "boys will be boys" thing. That's all. You guys have a high
performance product and committed it to the RC world. That's very cool. If you have
any input feel free to jump right in. But around here...... use some protection

P.S. nobody said anything about "the bottle".