Workshop happenings

[exeric]

Good points on rod accuracy Tom. Your last picture says it all.

[fillibuster]

Cotten, my key stocks are used like your beams are, but to be sure, let's confirm that we are checking that clearance with the crankshaft at both 4:30 (of the clock) and 7:30 (approximations). This helps indicate a twist vs a bend. If the right hand side is lower than left at 4:30 but higher at 7:30 we have a twist. If right hand side is comparable at both positions we have a bend. A consistent zero-clearance on both sides of the rod shows straightness.

[fillibuster]

Tom, I would like to read your comments on the ill effects you have experienced, such as on the spindly Indian forked rod.
I have a bar that you'd throw in the scrap pile, a wrist pin with two handles welded to it. I don't use it much anymore, but got a lot of miles out of its results.

[T. Cotten]

Filibuster!

The problem is obvious in that the races "splay" askew when the rod is forced. I guess the proper words to describe it elude me, but the point is that you can quickly get a bind.
Even stout H-D rods will 'move', even if you do not notice for a while.

I have my Indian female rod bench fixture to photograph, but health issues are in my way again....

Measuring from ancient and variable decks can only give us clues.
Assuming the decks happen to be perfectly square (more likely for a milwaukee machine than Springfield's, I suspect..), bend is obvious when there is a difference from left to right.
Twist would certainly increase the difference, but if it happens that there is no bend, shouldn't the pin still come down square to the deck at any degree of rotation, or 'time o'clock'?

You didn't really tweak directly upon the wristpin bushing, did you?
My bar punishes the beam only (attached). But I preferred other torture devices.

...Cotten

[Steve Little]

Here's a photo of my two HD factory ones.
The smaller one is for the 1926 on singles and the other is the big twin one.
Somewhere I've got the instruction sheet for them but I can't lay my hands on it right now but I'll keep looking

Hi Thommo. Neat set of tools. Are you suggesting theres a picture of the Big Twin plate in the service manual? I thought tI was making a tool that didn't exist... more a melded design from two different HD tools, but maybe I've been driven by subliminal prompting.
I'll have to re read my Knuck and Pan service manuals.
Wife did suggest to take a book or two. Maybe a couple of service manuals stuffed into the bottom of my bag for some light reading.

[fillibuster]

Filibuster!

The problem is obvious in that the races "splay" askew when the rod is forced. I guess the proper words to describe it elude me, but the point is that you can quickly get a bind.
Even stout H-D rods will 'move', even if you do not notice for a while.

Okay on that, Tom, but I'm a bit suspicious. But the later Chiefs appear heavy enough in the low end to assure that any "give" would be in the beam.



I have my Indian female rod bench fixture to photograph, but health issues are in my way again....

Measuring from ancient and variable decks can only give us clues.
Assuming the decks happen to be perfectly square (more likely for a milwaukee machine than Springfield's, I suspect..), bend is obvious when there is a difference from left to right.
Twist would certainly increase the difference, but if it happens that there is no bend, shouldn't the pin still come down square to the deck at any degree of rotation, or 'time o'clock'?

It's checking in both positions, of course, that confirms twist vs bend. Twist a straight rod, then, in your mind. One end of the wrist pin hits the deck (key stock blocks for me) at 4:30, the other end of the wrist pin hits the deck at 7:30. .... and I like to get the "rock" out of the decks before we get to this stage. I do like Steve's plate for that.

You didn't really tweak directly upon the wristpin bushing, did you?
My bar punishes the beam only (attached). But I preferred other torture devices.

...Cotten

Yeah, I tortured the wrist pin bushing, Tom, but that was a long time ago. .. Say, if the rod was bent, what made it that way? birth? or a seized piston? or what? Did the piston exert force through the wrist pin and then the bushing? So what are we now trying to protect?

[Tommo]

Here's how HD told you to align rods using their surface plate and Cotton it's not how I would do it or advise anyone else to do it.

[T. Cotten]

Sorry for a late reply Filibuster...

It was a blue-printed "late" Chief rod that would no longer accept the crankpin and rollers after a 'conventional' tweaking.
You can't straighten a rod for bend or twist until races and bushing are fitted, as those operations add error, and the massage made things move.

So I conjured an expandable collet to hold the female rod in a press to keep the races firm while punished (attached).

Bend and twist are a lot more manageable than an offset, which is even more difficult to detect while assembled.

....Cotten

[fillibuster]

Sorry for a late reply Filibuster...

It was a blue-printed "late" Chief rod that would no longer accept the crankpin and rollers after a 'conventional' tweaking.
You can't straighten a rod for bend or twist until races and bushing are fitted, as those operations add error, and the massage made things move.

So I conjured an expandable collet to hold the female rod in a press to keep the races firm while punished (attached).

Bend and twist are a lot more manageable than an offset, which is even more difficult to detect while assembled.

....Cotten

My chemistry prof used to say, ".. if you can appreciate that..", as in "recognize the full worth of.."
So I appreciate your contribution. Dam, there's just no end to the tooling required for perfection.
Is "perfect" the enemy of "good"? I heard that once, from a doctor.
The hub of an alignment tool appears to be the shape of the arbor of a sunnen hone stone rig. Can't tweak on that.
I once cut a shaft to as close a fit as I could manage, this prior to lapping.
Honestly, how diligent are our builders who do work for others? Do they really possess more sophisticated tools than clubs and rock bars?

[T. Cotten]

...Honestly, how diligent are our builders who do work for others? Do they really possess more sophisticated tools than clubs and rock bars?

From my experience, Filibuster,..

The truly diligent can't make flat-rate.

If I don't make a new tool every day, my day is wasted.
But there is certainly a place for clubs on my wall. Several, actually.
Not sure about "rock bars" though. I have a pre-Columbian meteoric iron celt, if that counts.

....Cotten