Cylindrical Square update Video online

[w1vlf]

Hey Guys,

I posted a video on YouTube about my exploits in trying to make a cylindrical square.
This is my first video and by any standard it is crude, but I wanted to show what I was doing.

Can one of you guys just watch it and see if there is any problem with my testing methodology?
I am hunting down larger wrist pins, in fact I found one 5 + inches long from diesel generator.

If there is something fundamentally wrong with my approach I would like to know.
Also I have acquired a .00005 indicator which should allow me to hand lap the face of the pin even closer I hope.

Here is the video: https://www.youtube.com/watch?v=Ofhek3Lbxkc




Thank you

PaulC
W1VLF

[pete]

A couple of things, your certainly damn close and with the equipment you have I'd say you've done really well. My personal opinion is that I much prefer the dial test indicator type as I think it makes the testing easier, but each to there own. It's also far better to have a large smooth radius on the front of your test stand. That way you just pivot the stand around until you hit the high point. You might want to back off on the preload of your indicator, it looks like .010" would be enough. It's just easier to keep track of where you are with only a partial revolution.

Funny but I just assumed my wrist pins would have truely square ground ends and haven't tested mine yet. What's even more odd about that is I generally just don't blindly trust anything. I have bought both a SPI 12" cylindrical square and that B&S 558 cylindrical square I mentioned in an earlier post. It might be worth setting up an Ebay search for one of those 558's. You never know, a cheap or at least cheaper one might show up. The nice part about them is you can use the one end that's ground off of true square for measuring how much somethings out, or use the other end just like the normal cylindrical square is used. I was planning on using my wrist pins as a 90 degree surface on the mills table to set work up, but now I know I'll need to check mine first.

There's more than a few Youtube videos showing that radiused face on the indicator stand, most seem to modify a Starrett surface gauge by adding a radiused piece for the part to ride against. I know The Tool and Die Guy shows that. Shadon HKW also does if you search through there videos. With that radius I think you'd find your testing to go much easier.

Edit, in one of the Guy Lautard books he talks about meeting with an old tool and die maker and lapping a block to some pretty tight tolerances. The guy weighted the high side of his part with a magnetic indicator holder so the extra weight would help to remove more material on that side. That also might help your lapping. You've started down a very slippery slope once you start hunting for real accuracy. It can become very expensive.

Pete

[duckman903]

Get lucky and find a DTI that reads to .oooo5" got mine at a flea market asked the lady how much and she said if her husband can't stay and sell his stuff I could have it for $5.00 (it's a Federal test in the box) yeah I know I took advantage but she named the price.

[mcostello]

He was out getting the bargains You did not get, probably made up the difference then some from Your sale.

[pete]

LOL, I think you might be right.

Pete

[refinery mike]

I followed your lead and bought two Caterpillar wrist pins. May be luck or lack of skills but i do not have anything that can find any need to correct the things. They came as perfect as i can measure. Thanks for the tip. I have always wanted a round square but could not cough up the high price of one. Even a rusty trashed one was on Ebay for over a hundred dollars. Thanks again.