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Author Topic: Making Better Fly wheels  (Read 10357 times)

SHIPCHIEF

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Re: Making Better Fly wheels
« Reply #15 on: February 11, 2006, 03:27:45 AM »
At what point do the flywheels  become too heavy, and wear the main bearings, or put excessive bending moments on the crankshaft?
Ashwamegh 25/2 & ST12
Lister SR2 10Kw 'Long Edurance' genset on a 10 gallon sump/skid,
Onan 6.5NH in an old Jeager Compressor trailer and a few CCK's

quinnf

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Re: Making Better Fly wheels
« Reply #16 on: February 12, 2006, 12:55:09 AM »
Scott,

That's a good question.  By means of an answer, look at the size of the TRBs on your 'roid, and then recall the size of the TRBs that they used to put on the front end of whatever species of Detroit Iron you may have driven in days of yore.  They were much smaller, yet each one supported 1/4 of the weight of the car with enough safety margin to handle all the live loads encountered from potholes, turns, curbs, etc.  Then consider how long those bearings lasted.  I don't think I ever had to replace a set of front end wheel bearings except when I tightened them too much once...ONCE!

But then again, you have a twin, so there are two power strokes 180 degrees apart, so your flicker shouldn't be as bad as that of a single. 

Quinn
« Last Edit: February 12, 2006, 01:02:33 AM by quinnf »

Mr Lister

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Re: Making Better Fly wheels
« Reply #17 on: February 12, 2006, 06:40:15 PM »
Guys,

There are 2 aspects to a "better" flywheel:

1.  Cast from steel so that it won't go bang at somewhere between 651rpm and 1000rpm

2.  Cast in a similar pattern to the Start-o-matic flywheels so the extra inertia makes starting loads easier and helps to reduce speed variations and flicker - ie a better generator flywheel.

One thing I learnt this weekend is that the original SOM even had an additional flywheel on the alternator pulley to increase the 1500 rpm rotating mass. This was apparently to assist the alternator in meeting the additional load, without putting extra strain on the drive belts.

My friend Paul, and also Guy Fawkes on this forum have the SOM machines. Perhaps they could measure up the flywheel to get the size, cross section and mass?

I agree with Guy Fawkes that the starter-alternator was an inspired bit of design from the 1950s, and perhaps it could be re-designed for low cost manufacture in China. I am sure that if you contacted some of the Chinese ST suppliers  - particularly those making the combined alternator/ welding generator, that they would consider making a special.  Those guys will make anything if they think there is a market for it!

I also think that there would be scope to built a direct drive starter-alternator into the flywheel.  Otherpower.com has led the way in this with their brushless PM wind generators.   An 18" diameter generator would fit nicely in the recess of the flywheel and make a very compact machine. You could fit same alternator to both sides of a twin.


Ken

GuyFawkes

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Re: Making Better Fly wheels
« Reply #18 on: February 12, 2006, 06:54:15 PM »
Start o matic main flywheels were a shade under 300 lbs each

main flywheel is (approx) 25" dia, 4" wide at the rim, 3" deep rim, 1" thick plate instead of spokes

alternator had a 14" flywheel, approx 3" thick.

Can't get copprmine on this site to work, so uploading some images and a crappy 640 x 480 video of her starting to http://www.surfbaud.co.uk/Lister/ in about ten minutes.

have phun
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Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.

Mr Lister

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Re: Making Better Fly wheels
« Reply #19 on: February 12, 2006, 07:29:37 PM »
Guy Fawkes,

Thanks for the dimensions and the photos!  I can now work out the kinetic energy at 650 rpm.

I see you bought the "red one"  that was briefly on ebay UK last week. 

Looks like you good a good deal/haul - complete with trolley and coolant tank.

Nice colour - Some of "our mutual friends" on a well know UK stat. eng. forum will be squealing


Best of Luck,



Ken
 

GuyFawkes

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Re: Making Better Fly wheels
« Reply #20 on: February 12, 2006, 07:43:13 PM »
Guy Fawkes,

Thanks for the dimensions and the photos!  I can now work out the kinetic energy at 650 rpm.

I see you bought the "red one"  that was briefly on ebay UK last week. 

Aye, 300 squid.. >;^)


Quote
Looks like you good a good deal/haul - complete with trolley and coolant tank.

the trolley is an aboniation, as is the coolant tank

Quote
Nice colour - Some of "our mutual friends" on a well know UK stat. eng. forum will be squealing

Best of Luck,

Ken
 

LMAO, yeah, bunch of bloody snobs...
--
Original Lister CS 6/1 Start-o-matic 2.5 Kw (radiator conversion)
3Kw 130 VDC Dynamo to be added. (compressor + hyd pump)
Original Lister D, megasquirt multifuel project, compressor and truck alternator.
Current status - project / standby, Fuel, good old pump diesel.