Grrrrr. I can't get my flywheels true.

[Bills37]

Talk about a dog chasing his tail. I'm dead nuts on the pinion shaft but I got .0025 on the drive side that I can't get out. Can someone walk a neewbie thru this? I lapped my pins in with lapping compound and the contact seems even all the way around. I'm at a loss here.

[diesel55]

hello are there any hair line cracks in the wheel taper /worn taper if used wheels.

[fillibuster]

Talk about a dog chasing his tail. I'm dead nuts on the pinion shaft but I got .0025 on the drive side that I can't get out. Can someone walk a neewbie thru this? I lapped my pins in with lapping compound and the contact seems even all the way around. I'm at a loss here.

Did you true the drive shaft with the drive side flywheel only? This helps. It takes a little trickery getting the centers of the true-ing stand that close together (I use another home-made set from a lathe bed). If the flywheel has a little run-out I smack the shaft with a brass club, or wood block, re-torque, and check again. Get this as close as you can. I had success also in using a brass shaft to hammer in the drive shaft with successive torque-ing and true-ing checks.
I'm usually suspicious of the taper of wheel and shaft taper matching, because I've had grossly poor fits. If you lap things in perpendicularly, it seems things should go that way, but I can't say I've done well with lapping.
Some builders will say, "Hey, these wheels are junk, get me some new ones". Hope you're better off than that. Go to the club.

[Bills37]

hello are there any hair line cracks in the wheel taper /worn taper if used wheels.

No cracks that are visable to the naked eye. As far a worn taper, I would think that it would show when I lapped the crankpin also the readings don't wander. Doesn't matter what I do. I can't seem to close this .0025 runout on the drive pin.

[Bills37]

Did you true the drive shaft with the drive side flywheel only? This helps. It takes a little trickery getting the centers of the true-ing stand that close together (I use another home-made set from a lathe bed). If the flywheel has a little run-out I smack the shaft with a brass club, or wood block, re-torque, and check again. Get this as close as you can. I had success also in using a brass shaft to hammer in the drive shaft with successive torque-ing and true-ing checks.
I'm usually suspicious of the taper of wheel and shaft taper matching, because I've had grossly poor fits. If you lap things in perpendicularly, it seems things should go that way, but I can't say I've done well with lapping.
Some builders will say, "Hey, these wheels are junk, get me some new ones". Hope you're better off than that. Go to the club.

Yes, I ran both wheels individually on centers. Their both within .0005. I'm using a lathe so distance isn't a problem. I just removed the QCTP & compound to get them out of the way. I'm new to this so maybe it's just part of the learning curve. I've done everything else to these engines in the past I want to learn this part of it. Not much info out there on the whole process and I've never watched it done. It seems to be a bit of a Dark Art.

Are you smacking the shaft or the fkywheel?

[fillibuster]

Yes, I ran both wheels individually on centers. Their both within .0005. I'm using a lathe so distance isn't a problem. I just removed the QCTP & compound to get them out of the way. I'm new to this so maybe it's just part of the learning curve. I've done everything else to these engines in the past I want to learn this part of it. Not much info out there on the whole process and I've never watched it done. It seems to be a bit of a Dark Art.

Are you smacking the shaft or the fkywheel?

When true-ing each shaft with its flywheel (pinion had no run-out) I had wobble in the wheel, several thou. Smacked the shaft a light tap with a 2# club on the end of an 8" 2x4, check true and re-torque and check true again, took about 6 of these exercises to get all wobble out of it. Then assembled crankpin, and slowly worked the true-ing and torque together, same process. I also clubbed a socket over the nut to help shock the wheels together on the crank, re-torque-ing and checking true as it progressed.
Patience. Can't be in a hurry. Results are gratifying. If it's your first time without seeing it done you're at a disadvantage. The indicators should tell you a number of things, but you will either club on one wheel or the other, or spread the wheels opposite the crankpin, or draw them together, a very little bit at a time. Watch both indicators concurrently for similar (or dis-similar) direction of run-out to determine which correction is needed.
Somebody's got a book that describes it better.
I've seen a little balancing handbook, but have never seen a true-ing handbook.

[Bills37]

If I read you right it sounds like I should start with less than a full torque on the nuts, true the wheels and then increase the torque and recheck until I reach the full torque spec.
I'll give that a try. Thanks

[fillibuster]

If I read you right it sounds like I should start with less than a full torque on the nuts, true the wheels and then increase the torque and recheck until I reach the full torque spec.
I'll give that a try. Thanks

I don't know many who do it that way, but it helped me. Thing is, every time you adjust the true of the wheels it seems to affect the torque. I clubbed the wheel with a socket over the nut to help set things a little tighter and firmer, and each time I did that the eventual torque was less. Last time it did not reduce at all. Gotta watch your forked rod/thrust washer clearance as you go.
I lost the felt washer on the pinion shaft last summer, and disassembled the cases, checked the true of the wheels, and they were still within .001. Built 10 years ago.

Have you checked in the engine building section? They discussed balance some time back. See if they talked true-ing.

[T. Cotten]

Bill!
Phil too!

Put the hammer down slowly, and let us approach this calmly.

Preparation is everything, and hardware with sixty or more years of duress benefits from a little caress:
http://virtualindian.org/10techfly.htm

Tapers can be corrected with a little patience.
But the more they are hammered, the more difficult it will be.

...Cotten

[Knotthed]

Kiwi has a lower end rebuild video that goes over this procedure.

I have not yet trued any wheels, but it seems fairly straight forward after watching his video.

You need indicators on both shafts at the same time, not one at a time when the wheels are assembled. If you only have one shaft with the flywheel between centers, the shaft should be dead on.

Perhaps, if you give some readings on the shafts in relation to the crank pin I could try to walk you thru his adjustment procedure.

For example; if both pinion and drive side shafts show both positive or both negative runout in the same location then the flywheels are not parallel with each other - you would either wedge or clamp opposite the crankpin to resolve this.

If the runouts are in different locations on each shaft then you have a rotational problem around the crankpin. To rectify this you would hold the assembly up on one wheel and smack the elevated wheel in the direction of the table thus rotating each wheel around the crankpin.

I think someone mentioned earlier, you should check your nuts for runout on the faces of them before assembly. I have been shown a repro nut that was shockingly bad, I could not believe it.

Hope this helps.

[Indiantim]

I had a similar problem last year, I found using a hardwood wedge between the flywheels was better than hitting the pheriphary of the wheels. Took me 3 days though to get them perfect. Read the VI section on lapping the tapers on a lathe, use a old pin as a lap with grooves to distribute the lapping paste.

You will get there in the end.

[fillibuster]

Bill!
Phil too!

Put the hammer down slowly, and let us approach this calmly.

Preparation is everything, and hardware with sixty or more years of duress benefits from a little caress:
http://virtualindian.org/10techfly.htm

Tapers can be corrected with a little patience.
But the more they are hammered, the more difficult it will be.

...Cotten

Hi Tom!
okay, I'm calm now, but you can call me reckless, I got a record!
I have this theory that the wheels' tapers are required to CONFORM to the shaft tapers, being just a bit softer. I've encountered new wheels and new shafts whose tapers were so poorly matched that the shaft, when placed into the wheel, wobbled terribly, and left only a 20% impression with the first 5 minutes of lapping. Another new drive shaft was required, which fit much better, but still had that wobble although very slight. Had I lapped that fit I doubt the tapers would have been conical (with straight sides), but rather more orbital. That is my disagreement with lapping taper fits, as I believe the shafts have that possibility of losing their taper form. It is the wheel that one should wish to conform, and old wheels likely have been DEFORMED to assume true in the past.

Who can say that the wheels were chucked in at zero runout prior to taper cut? or perpendicular to the cutter on a mill? or that the cutter was running true?

I welcome criticism, btw, as my peers perceive me as a crude cowboy, a modest one at that.

Bill's getting some good feedback.

[fillibuster]

I had a similar problem last year, I found using a hardwood wedge between the flywheels was better than hitting the pheriphary of the wheels. Took me 3 days though to get them perfect. Read the VI section on lapping the tapers on a lathe, use a old pin as a lap with grooves to distribute the lapping paste.

You will get there in the end.

I agree with this plight. Patience. Some take time, those fits ARE NOT consistent!
Bill, just confirming (I re-read your earliest posts); you first checked the wheels' runout with a dial indicator or the outside face with the shaft on centers, rotating? and had .0005 runout on the dial? one at a time, pinion shaft with pinion wheel only, then drive shaft with drive wheel only?

[fillibuster]

I had a similar problem last year, I found using a hardwood wedge between the flywheels was better than hitting the pheriphary of the wheels. Took me 3 days though to get them perfect. Read the VI section on lapping the tapers on a lathe, use a old pin as a lap with grooves to distribute the lapping paste.

You will get there in the end.

I'm failing at finding the vi site. GRRRR! dam computers! where's my club?!!

[T. Cotten]

Phil!

I have no problem with the principle of tapers conforming to accept the shaft,
as it is much like pulling a nail into oak. The Z wheels are "malleable".
(It seems that brandX hardened their wheel tapers by pulling the pin .060"!)

The tapers have a work-hardened surface from the last assembly.
Disrupting this thin layer allows it to conform for the next assembly.

Lapping techniques ordinarily are only applied for removing burrs or 'high-spots'.
My re-alignment techniques upon a lathe may seem brutal, but they served to correct the wheel tapers enough to give the truing assembly a great deal more control, and occasionally the mallet could be spared entirely. A brief discussion of assembly techniques can be found at http://virtualindian.org/1techflywheel6.htm

(The initial installment of the series is http://virtualindian.org/1techflywheel.htm
If these links will not work for you, try http://vifiles.org/10backissues.htm for the VirtualIndian web magazine back issues, and check out issues #1 and #6.)

It was my practice to routinely lapp all four tapers.
Thereafter, I was finally able to make flat-rate,
and sleep better at night as well.

....Cotten