Air starter

[XYZER]

Will it go through compression with a run at it? I went the 12 volt route and found if I roll the flywheel backwards and give it a run at it there is no problem. I did find out if it is outside a little water on the flywheels will cause excessive slippage.

12 volt starter
http://www.youtube.com/watch?v=_QmWXNo-Gmg&feature=channel

[fabricator]

I think his air start system sorta kinda borders on OCD  If anything ever happens to the guy, no one will ever figure out the plumbing if something should go awry.
Ron

That is pretty much what I thought, there seems to be two surge tanks, lots of copper tubing and some kind of horrendously complicated valve, which he seems to pull a popsicle stick or something out of after it starts.

[fabricator]

Will it go through compression with a run at it? I went the 12 volt route and found if I roll the flywheel backwards and give it a run at it there is no problem. I did find out if it is outside a little water on the flywheels will cause excessive slippage.

12 volt starter
http://www.youtube.com/watch?v=_QmWXNo-Gmg&feature=channel

Nope, if I turn it all the way back up against compression then hit it it just stops, it just don't get up enough speed in that partial revolution.

[LowGear]

What stood out to me is the rubber wheel size is so much smaller on this last video "Listeroid take 2 starter.AVI".

Casey

[XYZER]

What stood out to me is the rubber wheel size is so much smaller on this last video "Listeroid take 2 starter.AVI".

Casey

The rubber wheel on the 12volt starter is from McMaster Carr. The starter has the power to push it through I believe but the rubber wheel will smoke when it hits the compression. Or I need more presure pushing on the starter.... 

[vdubnut62]

What about a urethane rubber wheel? My experience has been better grip and they don't "self lubricate" when they do lose grip.
Maybe a cheap roller skate tire/wheel?
I used to work for a torque converter rebuilder that used urethane tires on the forklifts that ran in oil on concrete floors. Messy!
Ron

[quinnf]

You might have a look at McMaster Carr #2474K103.  http://www.mcmaster.com/#drive-wheels/=egmu5e  

I picked up one a while ago after trying the hockey puck which was too hard/too slippery against the flywheel, and adapted it to my Gast 4AM, and then to the shaft of a Toyota Camry electric starter that I think will be the one I go with for starting Old Silver.  It's made from softer rubber, so shouldn't need as much pressure against the flywheel to achieve traction.  With the hard hockey puck I found I was having to press it so hard against the flywheel to prevent it from slipping, the pressure was causing a lot of drag on the bearings in the Gast, robbing it of torque.  I've run it several times just holding it against the flywheel and it has good grip with no tendency to burnout.  

Just received a Grizzly G0463 mill so can now proceed to make the rest of the apparatus (this is turning out to be an expensive project!   ).  I plan to use pneumatic cylinders to activate the decompressor lever and fuel rack safety (it will be held closed by a spring; air pressure will retract against the spring).  Loss of air pressure will push in the fuel rack. 

Though I have two Gast 4AM motors, I think the Toyota starter is a better solution especially on cold mornings when you're going to need all the torque you can muster to overcome viscous oil.

Quinn

[vdubnut62]

I'll be. Is there anything that McMaster-Carr does not carry a special purpose part for?
I never imagined a special drive roller, probably even has a special compound rubber for the job.
I learn something here every day.
Ron

[fabricator]

If I decompress the wheel I got works great, so I guess I'm gonna stick with what I got, it's a 3 inch rubber wheel that don't slip at all.

[LowGear]

Too bad you can't turn it down to 2.5".  I know it only seems like about 16% change but that might just be the extra torque you need.  I'm talking through my jean pockets here just so you know my credentials.  But if you think that's malarkey then let me forecast a higher speed rotation on your flywheel.  I've been shoveling 1/3 mix for the farm much of this morning so my little gray cells are way over charged with oxygen and sugar.

Casey

[fabricator]

Oh I can stick it in the lathe and turn it down to 2.5" no problem, and I have several more of these wheels so if it don't work it's no big deal.

[XYZER]

You might have a look at McMaster Carr #2474K103.  http://www.mcmaster.com/#drive-wheels/=egmu5e  
.

I followed Quinns research and got the same wheel. Pushing it through compression takes real grunt, air or 12v if you are up against it!

[LowGear]

Slow down Fabricator,

Please let some of the more "down to earth and knowledge" people give the 2.5" theory some thought.  But if you do try it I'll buy you lunch the next time you're in Kona.

Casey

[Carlb]

I am using a soft rubber wheel from Mcmaster carr it is 2.5" in diameter and even if you backup the flywheel before starting it will not get past compression.   The air starter just doesn't make enough torque at low rpm and it can't spin up fast enough before hitting the compression stroke.  I am feeding my air motor via  1" pipe with a 1' length 1/2" hose and 135psi of air pressure. With my decompression lever engaged it will spin the engine up to as high as 200 rpm but it really isn't necessary.  It will start even spinning the engine at 100 rpm before disengaging the compression release.

If automation is the goal then just use a solenoid to disengage the decompression lever when you turn off the air to the air motor.  If you let the air motor get the engine up to 150 rpm or so then turn it off the engine will have more than enough stored energy to start when the decompression lever disengages. 

[quinnf]

If you're going the air route, consider plumbing into the main air line a small pneumatic cylinder to actuate the decompressor.  That way you have only one valve to turn and you can keep your hands away from greasy rotating parts which is important if you want to automate or have wife/kid be able to start the engine safely.  Air cylinders are ridiculouosly cheap (surpluscenter.com) simple and reliable.  Even though I have decided to use the Toyota starter to spin the flywheel I'm still planning to use air for the decompressor and fuel rack shutoffs.  I might rig up the Gast 4AM just for grins and because it makes such a great sound, but for reliable delivery of torque when you need it most, it's hard to beat an electric starter of some sort, especially if you know you're going to need 12V for the glow plug, control system, emergency light in genny shed, etc.

Quinn