30cc charger engine

[Stumpy]

Here is a few pics of my little charger engine. This is more of a test for me and my ability to design and use my cnc mill

Its a 30cc OHC flat twin with a supercharger on top along with 2x cam belts running of the front and one belt running out the rear for the charger. The power for the rear belt is taken of the end of the crank pin so it sort of has a PTO there is all so space under the crankcase for a starter motor to run off the same shaft but ill only make that if it runs with out spiting its guts out first.

The hole engine is based on the nemmet/lynx 15cc engine iv just added my little bit for the extra cylinder and the charger PTO the charger is based on a full size item but iv taken in to account that it can be made on a manual machine that's whys there's no rib's on the out side of the casing and there is of the shelf cheap gears in there to help with that idea.

But if you want to now more about the charger just ask as

[metalmad]

R u kidding Mate
Show me more
Looks like a great little engine to me 
with a Blower 
Pete

[dsquire]

Stumpy

As far as a test of your abilities it looks to me as though you are passing with top marks. I will be watching this as you finish it up and add the starter to it. Thanks for showing it to us. 

Cheers 

Don

[metalmad]

A Starter Motor 
How would u build one ??
Pete

[Stumpy]

For the starter motor i would like to use a in runner out runner like you would find in a RC car or helicopter as i don't like the look of a steel 400 size can motor but saying that after being in side a few DeWalt power tools there could be some thing to be made out of there frame less cordless drill motors but i ll cross that bridge later.

As for how i would get the drive to the crank iv all ready planed a head on that that's why the out put shaft Out the back of the engine is very much to long at the moment. The idea is that once the charger pulley is fitted to the said shaft i can press on a hardened steel sleeve then there will be a one way bearing in side the driving gear running on the sleeve.  So I'm then hoping that the motor under the crank case can drive this pulley with a belt from the motor.  The hole system should work just like a IC model helicopter starting set up once the engine is running you shunt the motor down the one way bearing then stops driving the engine. That's the idea and the plan at worst it will look trick under there.

[Jasonb]

Nice job on the engine, looks like you have got your CNC running well.

Now how about finishing that Fowler

Jason

[Stumpy]

Hi Jason

The mill is all sorted now.  As for the Fowler i no longer have it i lost all intrest in it.

[Brass_Machine]

...

But if you want to now more about the charger just ask as

Ummm Yup. I wanna hear more about the charger.

 

[Stumpy]

Sorry about the delay I'm my reply but i only come on line when I'm not in the workshop witch is not to offen

Im not ot sure what more to say about the charger apart from the fact that i have have taken the measurements from a full size blower put them in to autocad and worked my way form there. To help work out the internal volume i sort of cheated i made work for my self at the same time because Mathe's is not my best even more so when trying to work out volume and all that jazz. So what iv done to get my volume and rpm is make a blower housing as long as i could with a 10mm extra long end mill and then measure the amount of fluid it will hold.  The reason for this is i have a twin that is 30cc total so I'm working on the fact that if i get a blower caseing that is 15cc and i spin it at twice engine speed I'm going to get twice atmospheric pressures going in to my cylinders and at that i can change pulleys to get what ever boost i want well that's the plan i could be talking total bull but you have got to have ago to learn.

While all that was going on and the reason for making such a long casing is because of my gear centres. By having a longer than i need housing i can keep milling it down until i find the volume im looking for of about 15cc. So if the charger was turning at engine speed i would get atmospheric pressures and it should run then i can just keep changing pulley size and have a good idea of wear im going with boost and rpm well that's my hope.


Back to the gearing you have no idea how hard it is to design some thing until you have to do it for your self. The reason for saying that is the fact that the hole thing is based around the to drive gears for the screws. The size of the gears and there centres are what dictated the total size of the casing. Trying to get every thing to fit on top of the crank case has come down to the size of said gears along with there centres and a lot of hrs of scaling to get it all on top of there but i did it in the end because you have got to remember that once you have the centres you then have to get you screws to move in that space. Iv plumed for MOD.1 RC car motor pinions 1 there very cheap and 2 there hardened (good old ebay) so after all that im on 18.02 gear centres and the hole set up has been designed around that.

Hope this is what you wanted to know and please if you see if im wrong in some why please tell me.  Iv learnt a lot form this like did you no the blower Bentley's use gear teeth profiles in there blowers witch is some thing i learnt after all the hrs i spent trying to make my own 

Just as a side note im not saying its going to work but a most it will look cool even if there is nothing in side it when its running hows is to know ????

[metalmad]

Hi Stu
that bit about the bentley blowers went right over my head?
Pete

[DMIOM]

Hi Stu
that bit about the bentley blowers went right over my head?
Pete

Pete - just google "Blower Bentley" and you'll see what Stu was referring to

they're magnificent !

Dave

[Stumpy]

Hi Pete

Sorry you don't under stand the bit about the Bentley I'm sure its because of my very bad typing skill's and the second is i forgot that some of you are on the other side of the world.  If you read the link below you will get a bit of a idea of what a blower Bentley is and all what they are about if you like a good read about racing you might like to follow that story some more.

http://en.wikipedia.org/wiki/Bentley_Boys

My comment about the gear teeth profile was to do with the vains in side the blower to get the vains to spin with out touching they used a gear profile in other words the vains are a 2 tooth gears but mine are based of some thing else totally different.

There is all so a very nice gentleman in the UK making a 1/4 scale blower Bentley engine witch is a work of art and this gentleman has all so been very use full and kind to me with my project and is over the moon with the fact that he is not the only one trying to make a charger.

Stu


P.s i do know im very poor at spelling and typing i do try and the spell checker can only work if i get the word spelled close in the first place.