Listeroid Friction Starter

[veggie]

Hi,

I'm trying to design a very simple system for starting my Roid.
In this case, a polyurethane or rubber friction wheel on an electric motor to drive the flywheel.
The proposed system is shown in the sketch below.

My question:
What HP motor do I need to crank the engine through it's compression cycles?
Anyone using an AC motor to start their engine ??

Thanks,
Veggie

>>> click picture to enlarge <<<

[veggie]

Jens,

The idea would be to spin up the flywheel and then flick the exhaust valve lever to fire the engine thereby using the flywheels to reduce the load on the motor.

Having a foot lever would be better than a handle...agreed.

Where did you get your friction wheel for the motor?
What RPM do you suspect your flywheels spin during startup ?

Veggie

[veggie]

Jens,

Very useful information. Thanks for that.
I wanted to stay away from the auto-type starter because of the mods necessary with the ring gear and the motor mounting issues.
I do have air available, but my compressor only has a 20 gallon tank, so I would have to upgrade the air system also ($$).

I only have 120, 15A available so I would be restricted to a 3/4 HP motor. I hoped with the 5:1 reduction against the flywheel, there would have been plenty of torque to spin-up the flywheels. But from your comments, I may have been too optimistic.

Due to the explosive power available from an automotive starter, it may end up being the best option.

Much to evaluate  

Veggie

[AdeV]

Hmmm... automated decompression isn't that difficult; Lister were doing it in the 1940s with the Start-o-Matic - maybe earlier. The decompression lever is simply replaced with a Yale lock style actuator operated by a 24v solenoid. The "Yale style" means it will always activate decompression, even if it pops out while the exhaust valve is closed, the slope on the underside allows the valve lifter to push the "lock" out of the way; of course, it springs right back after the flange on the lifter has gone high enough & bob's your uncle.

So, don't be afraid of automating the decompression side. As an added Brucie Bonus¹, you automatically get a means of stopping the engine in the event of an oil or coolant problem; just cut power to the solenoid & the decompresser pulls itself in by spring power.

To spin the engine up, I'd look at adding an auto starter, but rather than meshing it with a ring gear, can it be altered to have a rubber wheel which engages with the alternator belt? Ideally, you'd want something which, as it contacted the belt (with the motor spinning and the engine stationary), would "dig in" to the belt & drive it forward; when the engine caught & started to shift the belt faster than the starter it'd be "thrown off" or "out" somehow. Not sure if that's possible, I'm just rambling here....



¹ In case you're not sure, a Brucie Bonus is (IIRC) named after the bonus available on a British game show (Play your cards right), hosted by Bruce Forsythe - a now octogenarian & still working entertainer.

[veggie]

AdeV,

After reading the advise of you and Jens, I am leaning to the automotive type starter due to the available torque and simplicity of wiring. Regarding the friction wheel, I was looking at some polyurethane wheels at Princess Auto. They had some flat solid rubber (nitrile) wheels also. Soft enough to get good traction against my flywheel. My first attempt will be a soft wheel contacting the flywheel directly.

The engineering challenge will be to mount a 3" - 4" wheel on the shaft of a car starter motor. (Very small shaft diameter with no keyway).

Thanks,
Veggie

[veggie]

Jens,

Yep, those same things occurred to me over the last few hours.
Either go with an automotive starter or an air motor....but not an AC electric motor as first pondered.
I took heed on you points about the flex plate "flexing", getting a flywheel as well as a ring gear, etc...
With my resources, the air system might be a simpler experiment (at first go round).

I flipped a coin and made a call.  
I went on Ebay and found a brand new Gast 4AM air motor which will be here next week.
I will fabricate a pivot base and engage the drive with a pneumatic actuator.
A polyurethane wheel will contact the belt to rotate the engine.
Right or wrong, you gotta start somewhere!

By the way, I noticed calrb's 6/1 starter on youtube uses a 4AM motor.
He drives the small 4AM motor with 80 psi using a 30 gallon receiver tank (5 HP compressor).
His engagement actuator is driven by 20 PSI air.
http://www.youtube.com/watch?v=LL2zUvQIIuY

Cheers,
Veggie

[veggie]

One thing I'm not sure about is the size of air actuator to pick up.
Princess auto has a good selection rated by bore size.
Bores of 0.8", 1.6", 2.5", and 3.4" with strokes varying from 1" to 9" for a total of about 15 sizes.
They don't state what linear force (in lbs.) that the cylinders generate at 100psi.

How did you select yours?
I was thinking of going somewhere in the middle... 1.5 bore with a 4" stroke


Veggie

[veggie]

Jens,

I'm ok with figuring the force from each available cylinder.
I'm just not sure how much force I need to create excellent traction (no slippage) against the back of the belt.
What do you estimate the force on your old air system to be?  (Wild guess)

Veggie

[BruceM]

Jens, it's considered polite to credit other people's designs when you use them and then post about them.  

The air motor starter using the Gast 2 or 4AM was my development. CarlB was kind enough to credit my design and I credit him with the clever idea of using a small regulator to reduce the pressure to the engaging air cylinder, and then using a single air valve or solenoid to both start the motor and engage the drive wheel.  I had to buy two different sized cylinders to get it right.

My design was based on an electric design which George B developed and showed on Utterpower.  As I indicated on the old forum, I use a Gast 4AM, though a 2AM was also tested and was (just) adequate for a 6/1.  You don't need a huge tank for either of these.   The 6AM is an air hog.

I think my air cylinder used to tilt the start platform into the flywheel is 3/4" diameter, operated at 90 psi.  I get no slip with that.  The drive wheel I use is from McMaster.com.  I use a shaft coupler with 1/2" ID and 1" OD to fit the rubber drive wheel ID.  The wheel is trued with sandpaper on the flywheel, spinning the motor, then hand tilting the wheel to the sandpaper.  This results in a smooth running setup with great grip.  The McMaster drive wheel has fairly soft rubber, which reduces the force required.  I would not recommend a hocky puck as a drive wheel because of the higher force required

I'll try to see if I can find the McMaster part number for the drive wheel and shaft couplers. Edit- Alas, the old forum is down and I can't find the part numbers.  Looking at McMaster, it appears that this is no longer available.  The wheel was about 2.5" OD, 2" wide, about shore 50 (a bit harder than an eraser)

The lower photo shows the original test setup which used a spring to engage the starter, you stepped on the maple board to disengage.  It used a drive wheel made from a rubber castor wheel, which was about 3.25". 

Best Wishes,
Bruce M

[veggie]

Hi Bruce,

Thanks for the input about how your system is set up. Good example of a pony motor starting system.

Not sure what point you're trying to make about "your idea"?
Using "pony" motors and engines to start Listers goes way back to the 1930's.
I'm sure you are not the first guy to use an air motor to start a Lister.
For all we know, you could be the 253rd person. Who really knows?

Cheers,
Veggie

[BruceM]

Veggie, you're certainly right, I don't own friction starters.

I did post about my Gast airmotor starter experiments in December 30th of 2005 and posted photos at Listerengine.com.  I provided similar information in other forums, and provided online forum and email support to several folks who made versions of it, including Jens.

I know Jens is such a prolific writer that he just forgot, and I regret mentioning it.  My apologies, Jens.

[veggie]

Bruce,

In your first picture (the one with the yellow hoses), is that an inline lubricator or a water separator ?
I'm wondering if I should put a lubricator on my 4AM motor.
My original plan was to plumb a tee at the air inlet of the motor with a plug in the unused branch.
The just open the plug and put a few drops of oil in every now and then.

Veggie

[BruceM]

Veggie,
Yes, the motor needs a few drops about as often as your rocker arm, if you can make that convenient via plumbing.  Consider a ball T instead of a cap, so that it happens regularly.

Yes, that's an oiler before my motor. (It was a freebee that came with a used motor) If I was to do it over, I'd use a large drip unit in the short 1/2" line.

My starter has been in service for  3 years,  3-4 or more starts a day.  So I have a fair amount of operational experience.

One issue I've had in the winter is water condensation causing rusting in the Gast cast iron body- and binding of the vanes.  The run time of the air motor is fairly sort with my setup and the glow plug, so all the water wasn't getting blown out of the motor.  I do have a water separator before the regulator, but it gets overwhelmed with the high velocity air requirements of the 4AM motor and passes water to the motor.  I get a lot of condensation in my buried air line- if I keep that blown out regularly, and the separator bowl near empty, it does fine. In damp weather it requires vigilance, something I like to avoid in design where possible.

Water is about all that will kill a well lubed Gast motor, in my experience.  I will one day fix my water related maintenance issue by using a way over-sized water separator, with an automatic bowl drainer.

Happy air motor starts,
Bruce

PS  I did find the rubber drive roller that is ideal for a 2AM or 4AM Gast motor starter- it's the 2474K72.  $23  (2.5" OD, 1" ID).  It's Shore A 60, not 50 as I remembered. I've had no noticeable wear on mine, and it grips well without excessive force.  That is important when no other drive wheel support is used other than the motor front bearing.  I also checked and I'm using a 9/16" air cylinder for engagement.

Some earlier posts about air motors are at: http://listerengine.com/smf/index.php?topic=2578.45 (2007)  Oddly, all of Jens later posts in this thread about his 6AM development have been removed, though you can read the responding threads.

[veggie]

Bruce,

The part number for the roller is very helpful.
I'm ordering two from McMaster. Thanks for sharing that.

Veggie

[veggie]

Jens,

Care to add anything to my order ?

Veggie