Fixture

[Steve Little]

While I was using the external hone in the rocker arm thread, I was thinking of another use.
Did a bit of mental design work and found a bit of stock to start the process.



Little bit of turning.



Push this back in here and tighten up.

[Steve Little]

After I had done this "in head designing", I thought, Right!! Here we go.
A tiny voice in my head...(the sane part) said Wait a minute!! Do a couple of measurements to see what's needed. After a mili second of mental wrestling I succumbed, and resentfully flicked the tape here...did some thoughtful, ruler taping on the job for a minute, (to fool myself that I was taking this seriously) and did a quick scribble Whallahh!!
1-1/2” round bar should be right. It'll be tight but the kicker arm should slide in between the jaws, without loosening them. Which will make change over fast.
When it was all done, I measured the clearance between the kicker arm and the chuck jaw....0.002”. Now I have to admit that was a little close for comfort. But hey.. A miss is a miss.



Quick clean of the centres

[larry]

Clever, and it uses the same tool as the rocker arm operation. A tool I never knew existed.

[T. Cotten]

Clever, and it uses the same tool as the rocker arm operation. A tool I never knew existed.

And I still can't find it on the Sunnen site.

....Cotten

[larry]

http://www.sunnen.com/graphics/asset...74c694ddff.pdf

I think this is it.

[T. Cotten]

Many Thanks, Larry!

My browser couldn't get past the chuck-like things on the left.
Now if they would only offer a replacement belt for my LBN pedestal grinder; Carl O. gave me a serpentine belt number,... but it don't fit my fossil.

I swear I will finally get a second lathe in duty this winter, I swear, and most likely I will be conjuring flatbelts for it as well as the ancient Sunnen.
(A fellow at Davenport gave me a critical clue for a source... but it doesn't browse up for me either.)

Steve's efforts are most admirable!

....Cotten

[harleytoprock]

I never knew an external hone existed! A new learn. But why not just use a toolpost grinder attachment on the lathe?

[T. Cotten]

I never knew an external hone existed! A new learn. But why not just use a toolpost grinder attachment on the lathe?

Well harleytoprock,

Although I have no experience with the Sunnen external hone, my experience with toolpost grinders suggests to me that it would be a lot faster, easier, and more certain of result.

(But then the toolpost grinders available to me were as much a piece of crap as the rest of the machinery.)

If you have only a few pieces to carve, go for it!

....Cotten

[BigLakeBob]

Many Thanks, Larry!

My browser couldn't get past the chuck-like things on the left.
Now if they would only offer a replacement belt for my LBN pedestal grinder; Carl O. gave me a serpentine belt number,... but it don't fit my fossil.

I swear I will finally get a second lathe in duty this winter, I swear, and most likely I will be conjuring flatbelts for it as well as the ancient Sunnen.
(A fellow at Davenport gave me a critical clue for a source... but it doesn't browse up for me either.)

Steve's efforts are most admirable!

....Cotten

I get all my flat belts from McMaster, from my old Southbend, B&S OD Grinder, and Sunnen Hone.

[BigLakeBob]

I never knew an external hone existed! A new learn. But why not just use a toolpost grinder attachment on the lathe?

I think what Steve is doing is great especially on the rocker arms, but I must say those kick arm shafts cut quite easily with a good grade of carbide. I have done quite a few then just make undersize bushings, just don't want to go too small, don't have that size in front of me right now.

[Steve Little]

I think what Steve is doing is great especially on the rocker arms, but I must say those kick arm shafts cut quite easily with a good grade of carbide. I have done quite a few then just make undersize bushings, just don't want to go too small, don't have that size in front of me right now.

During the process of cleaning this lot up, Ive been thinking the same thing.
The bushings are machined to the shaft size anyway, but I wonder what under size, the shaft stops making a "sealed" contact to the quad seal?
I made some calls to a Hard Chrome, and metal spraying, companies a couple of days ago to enquire about costings.
But the metal spraying also requires some more thought. The kicker arms are made of stout steel (Chrome Moli?) Metal spray involves a lot of heat. Will the kicker arm need to be tempered after machining if this process is used?
I should say that I used the lathe to take the middle "high" section out of the shaft. This was to save the life of the hone stone. I finished off with the hone.



Bring your knowledge to the table.

[Steve Little]

harleytoprock
I never knew an external hone existed! A new learn. But why not just use a tool post grinder attachment on the lathe?

Hi Toprock
When I saw Bob's grinder in the "rocker arm" thread, I was struck green with envy. I don't have any type of precision grinder, but I can say that I'm enamoured with this external hone.

I'm imagining a guy at Sunnen head office scratching his head and asking, what the hell's going on with all these FB hone enquiries?
I'm feeling that, posting a picture of my collection is probably bad form.
Also shows some level of my addiction for good tools. I will eventually purchase a FC as well.

[Steve Little]

I don't have a NOS, OEM, shaft to measure, so I used a new #33096-54B JIMS shaft to determine the correct size.
The JIMS shaft measures 2 tenths shy of 0.750”
I'm guessing the tolerance is probably +000” /-0005”

I tried a couple of “James gaskets #33076-37” quad seals on the JIMS shaft and it has excellent surface tension.
After fitting the “James” quad seals to a range of under sized shafts, I can report that they loose contact with a shaft at about 0.733”
I don't have any OEM seals, so cant make an assessment if they still hold at 0.733”

James Gasket quad seals, still have minimal surface tension at 0.738” but my guess is they may leak through capillary action.

I plan to get a couple of the smallest shafts Hard Chromed, and I will hone them to 0.750.

Future Steve, will report back then.

Feel free to debate, discuss, or write a scathing rebuttal, to any, or all, that I have surmised.

[Bruce T]

G’day Steve, Informative thread as usual from you, thanks. Just a quick question relating to the photo of the seven 41-up starter cranks you posted with this thread. Counting the cranks from left to right in the photo, it appears that cranks 5 and 7 are slightly different than the others. The bends on these two cranks are more rounded. Do you know if there were two variations of the 41-up starter crank?

[Steve Little]

Hi Bruce.
I see it now you've pointed it out.
Just up from the machined shaft, is the first bend which gives the kicker arm clearance from the muffler.
All but two arms have a sharp, distinct, bend. The two that Bruce has identified don't.