8541Hawk

All I know is Rodger was of no help to me what so ever.

E.Marquez

Quote:

Originally Posted by killer5280

Finally did my flywheel. Since I put it back on I have only ridden about half an hour due to freezing my *** off. The differences are subtler than I had hoped. I didn't have any trouble pulling away from a stop and the low end power seems about the same as before. Overall it seems a bit smoother and revs a bit quicker, but it's certainly not a night and day difference, although I didn't get a chance to really ride it hard. I'll give another report when the weather warms up and I have a chance to evaluate the changes more thoroughly.

Bringing up an old thread to ask a question of those that cut down there own flywheel..

How did you chuck it up?
3 JAW and shims? 4 Jaw? Use a backing plate? tapered spindle? use the alt basket itself?, remove from the gear and use internal 3 or 4 jaw setup?

killer5280

I didn't do it myself, so I can't answer your question.

autoteach

3 jaw and shims. Could have done 4 jaw, but there is a risk of uneven clamping pressure altering the shape of the basket. I removed all parts that I could.

E.Marquez

Quote:

Originally Posted by autoteach

3 jaw and shims. Could have done 4 jaw, but there is a risk of uneven clamping pressure altering the shape of the basket. I removed all parts that I could.

Bill; Thanks for the response.

Im a little concerned out clamping down tight enough on the basket to lock it place. And as well, understand the basket in not built, machined with near zero run out, nor accurately indexed to the portion of the assembly that attaches to the crank (tapered hub center)
So thinking I can address both my concerns by making a backing plate to be chucked in to the 3 jaw chuck.. The plate would have a tapered spindle to it on the front side, the fly wheel could then be bolted to the backing plate. No clamping on the basket, and the assembly when cut down would end up concentric and minimal run out relevant to the like installed manner on the crank (indexed to the hub center on a tapered spindle (crank snout)

Yes, more difficult than just clamping it in a 3 jaw chuck… but then that method you need to ensure it is evenly in the chuck with minimal run out for fore machining.

If I make the backing plate with tapered spindle..,,next set up is as simple as chucking up the backing plate and slapping the new flywheel on , one center bolt later, you’re ready to cut.
Thoughts?

CrankenFine

So are you thinking of doing this kind of work for other forum members with this custom backing plate? ( for a fee of course!) Seems like a waste to build such a nice tool and only get to use it one time.

E.Marquez

1St, Take that Back,, Never speak ill of a tool, or the building of one.
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2nd; Yes, and kinda.
I might entertain cutting down others flywheels.after I do mine and am confident in the procedure.. but the real reason is, Im not confident it chucking up the flywheel assembly by way of griping the basket. Yes, it's been done by folks on this very list, with success. And likely some of the ones who had it outsourced, the machinist did the same.
All the same, if I can come up with another way of doing it, im going to give that a shot first.

killer5280

Did you read post #66 in this thread?
https://www.superhawkforum.com/forum...e7/#post190002

E.Marquez

Yes sir, though you linked to post 91.... so did you mean 66? or 91?
66 says So yes, one rider chucked up the flywheel from the basket.. I got that.
Two issues I want to avoid.
Distortion / damage of the basket.
And if done this way, once reassembled, it is not trued to the center line of the tapered bore as installed on the crank..

If a backing plate is used, with a tapered spindle on line with center of the portion that is chucked up in the lathe,, when you cut the fly wheel, it will be true for run out in the same axis, position as is when it is installed on the crank.

They say people that are self taught have terrible teachers
Likely so, and Im not a school trained engineer, nor machinist. So If I'm missing some engineering concept, or machinist procedure, speak up.

Im not school trained, but I am trainable.

In the end, I may just chuck the basket in a 3 or 4 jaw chuck, and cut the dame weight down,,,, but Im sitting in Afghanistan right now, so for the next 6 months, i'll keep considering alternate ways to do this easy job..

8541Hawk

Well I used a 4 jaw chuck just because, for me, it is the easiest one to get all the run out removed when doing a one off type of thing.

Now if I was going to do a run of them (even though I have done a few lately.....) this is how i would set it up.

The most important comment is remove the sprag clutch (the one way bearing for the starter) before doing any cutting. It is only 6 allen bolts and drops right out and do you really want to take the chance of having a bunch of chips floating around inside your engine...... just take it out, it's easy.....

Then for cutting:

First I would use a lathe with a collet chuck.

Then find the largest collet you have or let's say 1.00" for this example (right around this size range should work with no issues)

The find a piece of bar stock (of whatever material you like, AL will be easier but will wear out faster, Steel is heavy and harder to work but lasts forever practically) in the 1.375 -1.5 " range. The total length needs to be around 12 to 18" to start, this is something to measure with a flywheel on hand before you start

I can't give you more exact numbers as i don't have a flywheel on hand to see what exactly will fit.

So hopefully your not lost yet and back to the tool.

Step one would be to chuck up the bar stock and turn down around 6.00" of one end so it will fit in the collet you have found. leave a nice shoulder to the O.D. of the material and make sure that the O.D. will fit down inside the flywheel.

Then take the cut end and put it in the collet. I would the leave .375 -.500 of the O.D. Then make another shoulder while turning the other end down so you can thread it to 22X1.5mm.

You will end up with something that looks like this


Sorry for the **** poor paint drawing but anyways, it would work by mounting the tool in the collet (which is self centering) and then thread the flywheel onto the tool. Then install a nut to hold it in place.

This is why I don't have exact dimensions for you, as i would need a flywheel on hand to see how deep the shoulder needs to be and things like how long the threaded section needs to be.

It just would be easier than messing around cutting a taper. Then you would also need a woodruff key to keep it from spinning on the taper. Also you wouldn't have to deal with the flywheel getting stuck on the taper either.

But like everything, there are many possible ways to do this and as long as the part is good, do whatever you are most comfortable with.

killer5280

I meant post #66. It's one guy's way of doing it, so I thought it might interest you if you had not already seen it.
I personally don't know nothin' 'bout no lathin'.

E.Marquez

thanks, nope not lost at all. And while the straight shank is easier to cut,, making a simple short length taper is not hard at all. You have a point on the release form the taper spindle,, but as I already made a puller from a hunk of steel i had and some cold rolled bar stock.. that not an issue either.

What I like is.. you understood what and why I am looking at mounting the flywheel the way I am.

Need? no, i could likely do it in a four jaw as well. Seems you and a few others have done it that way with success (no crushed basket, no pieces of magnate came crumbling out. )

Thanks for the confirmation of process.

8541Hawk

No worries, I was just looking at it from what would be the easiest to set up to get good repeatability.

And like I said, there any many ways to do the same job.

One thing I would say is, as you are using an AL backing plate and centering on the taper, You might want to see if you could use the 6 allen bolt holes as hold down points.

Just drill and tap the pattern on the backing plate, find the right length bolts and the possibility of it spinning on the taper is gone....

E.Marquez

AL? Umm, if I did it in AL it would have the backing plate drilled and tapped and not mess with the taper shaft at all.. but then I lose out on centering the flywheel in the same axis as will be on the crank.

As you suggested, I'll use my collet chuck, with a 1.125 collet (largest I have) and cut a spindle with a shoulder to both set depth into the collet, and to clamp the flywheel against. Taper it 1deg under the flywheel taper and it should lock up tight enough to not need a key.. though I can cut that if needed as well.. The spindle will be from 4140, 3.00 dia as I have a 3 foot hunk. I'll cut it to within .002 of final dimension, then grind the final taper to get 70-80% contact.

8541Hawk

See that is the beauty of the internet.... I miss understood your set up and was thinking something completely different.

Now that you clarified what you are doing , sure that should work fine.
I'm not sure what the factory taper is on the flywheel bore but 1deg difference does sound about right and you can always check for contact area with a little dykem and adjust the angle as needed.

So sounds like your good to go....