Machining a flywheel

Anything related to Lambrettas... ask tech questions, post helpful info, or just read and learn.
User avatar
Doom Patrol
registered user
Posts: 1823
Joined: Wed Jan 07, 2009 5:03 pm
Main scooter: Jet 200
Location: Second star on the right and straight on till morning
Contact:

How do you turn down the fins on an electronic flywheel? Is it just a question of putting it on a lathe?
WINTERMODEL150
registered user
Posts: 436
Joined: Sun Oct 17, 2010 5:31 pm
Main scooter: lambretta ld auto
Contact:

Doom Patrol wrote:How do you turn down the fins on an electronic flywheel? Is it just a question of putting it on a lathe?
I cut the end off an old crankshaft bolted it to the flywheel and give it to my machinist who then turned it down.

Dean
User avatar
Doom Patrol
registered user
Posts: 1823
Joined: Wed Jan 07, 2009 5:03 pm
Main scooter: Jet 200
Location: Second star on the right and straight on till morning
Contact:

Do you mean layshaft? That was what occurred to me as being one possible way of doing it. It's a SIL flywheel and they are supposed to be turned down to the correct height. But for some reason this particular one looks like it could do with losing another couple of millimetres off it.
rosscla
registered user
Posts: 4823
Joined: Tue Oct 25, 2011 9:50 pm
Main scooter: Lambretta
Location: Lanarkshire
Contact:

I think he means crankshaft as that's what the flywheel mounts on which would then be able to gripped in a lathe.

Wouldn't it be easier to get the longer indian cowl ?



Don't longer fans move more air? There are some issues about shortening the fins and the gap between the fins and the cowl shouldn't be too big.
"Our dilemma is that we hate change and love it at the same time; what we really want is for things to remain the same but get better."
User avatar
Doom Patrol
registered user
Posts: 1823
Joined: Wed Jan 07, 2009 5:03 pm
Main scooter: Jet 200
Location: Second star on the right and straight on till morning
Contact:

Crankshaft of course. My apologies wintermodel. I can't believe I said layshaft. I'm getting my shafts mixed up. I am using an extended cowl as it is and it clears the blades of the fan nicely. A bit too nicely. It's actually too deep and vibrates against the foot board. As it's only a matter of millimetres that prevents it being used with a standard cowl I did wonder if turning the blades down might be a viable option.
WINTERMODEL150
registered user
Posts: 436
Joined: Sun Oct 17, 2010 5:31 pm
Main scooter: lambretta ld auto
Contact:

Doom Patrol wrote:Crankshaft of course. My apologies wintermodel. I can't believe I said layshaft. I'm getting my shafts mixed up. I am using an extended cowl as it is and it clears the blades of the fan nicely. A bit too nicely. It's actually too deep and vibrates against the foot board. As it's only a matter of millimetres that prevents it being used with a standard cowl I did wonder if turning the blades down might be a viable option.
Just bent the foot board down out of the way .

Dean
User avatar
corrado
Dealer
Posts: 2588
Joined: Thu Jan 08, 2009 1:12 am
Main scooter: Lambretta GP
Location: Top of Blackpool Tower
Contact:

[quote="Doom Patrol" I am using an extended cowl as it is and it clears the blades of the fan nicely. [/quote]

You don't want "nicely" clearance, you want it as close as possible without touching the fan for the best cooling effect.
mark
registered user
Posts: 1547
Joined: Sat Jan 10, 2009 10:41 am
Contact:

easier to mod cowling by just elongating screw holes tbh and its more adjustable that way
OzOAP
registered user
Posts: 306
Joined: Sat Aug 01, 2009 2:11 pm
Main scooter: Vespa PTS1E
Contact:

Was told by 'an expert' (there are a lot about), that the tall fin ones dont flow anymore air than short ones, coz of the air gap between them.
I use to leave fins 'indian' height but remove everyother one.

Image
User avatar
Doom Patrol
registered user
Posts: 1823
Joined: Wed Jan 07, 2009 5:03 pm
Main scooter: Jet 200
Location: Second star on the right and straight on till morning
Contact:

corrado wrote:I am using an extended cowl as it is and it clears the blades of the fan nicely.
You don't want "nicely" clearance, you want it as close as possible without touching the fan for the best cooling effect.[/quote]

I know. I'm aware of that and that's the real reason I want to get it done. Although, in all fairness it doesn't appear to have had any detrimental effect. But, as the cowl is rubbing on the footboard it's the perfect excuse. Odd though. It's a SR flywheel and turned down to the correct height. but plainly still a tad too tall.
Post Reply Previous topicNext topic
  • Information
  • Who is online

    Users browsing this forum: No registered users and 8 guests