Rops pin mod.....Updated and finished!

[Runs With Scissors]

Back story for those unfamiliar: I stopped at McDonalds to get some food and it was Drive-Thru only. So I had to put my ROPS bar down and about halfway through unscrewing those damn ROPS bolts, the sky opens up and soaks me.

I decided to get some Lynch pins and turn the end down and make the ROPS "Quick Takedown".

For the life of me I could not figure out how to hold the Lynch pins in the lathe. Out of frustration, I just ground them down by hand on the bench grinder, painted them up and called it good.

Well every time I walked by the General Lee, those damn pins would mock me by making comments like; "Hahaha ......You suck Paul, you had to hand grind us... and now we look like sh!t and are rusting to boot....Hahahah"

So after enduring this bullying for months, I decided that a man can only take so much......

I decide to make some Stainless Steel pins. Not much planning was done, so lets see how this turns out.

 

[Runs With Scissors]

First I took some crude measurements. I liked the look of the Lynch Pins handle; However, the big end where the handle is attached does me no good, because the pins inserted length will be dictated by the distance of the turned shoulder.

Some crude measurements and 1.3" seems like a good shoulder length.

Now for the tricky part. ( BTW I am NOT a machinist by trade, only a weekend warrior)

In my research, I see that work hardening SS is problematic and I want to avoid this so I bought some 304 SS hoping that it will provide good enough corrosion protection and be easy enough for a non-professional to work with.

I eventually indexed it to within .003 but forgot to take a pic. I think that's good enough.

 

[Runs With Scissors]

I hand grind and sharpen all my own lathe bits, so I picked out a profile from my 1954 Machinist school book that I use for reference.

Then found the center of the piece.....That's seems pretty good.

The first pass goes "reasonable", but I am still worried about work hardening, so I hope some of my Magical Mystery Cutting fluid will help.

Then I decide to press my luck and take a deeper 2nd pass

 

[ve9aa]

Now the secret is out !

(soaking your tools in Heinz tomato juice)

Cheers and keep the great posts coming. I love these watch you build/mod type threads...

 

[Runs With Scissors]

Then the WTF moment hit me.....I bought 5/8 round stock, so I only needed to take off about .025"

AHHHHHH....... Son of a B!tch!!!!!

Well now I've really stepped in it.

I only had enough stock for 2 pieces, assuming no mistakes.

Well now I suppose it's time to make some Lemon aide with these Lemons.

I decide to now "practice a bit" and see what settings work the best.

The first pic looks like Hammered Dog Sh!T, so a few more test passes gets me into the ball park.

 

[Runs With Scissors]

The finish still looks like crap, but it's the best I can do with my limited skillset and knowledge.

At least I picked up a few ideas on how to make it appear that I know what I am doing. Hahahaha

Break out the emery cloth, and the 5th grade math skills.

Lets see if I remember how to do division "old school"

Back to the lathe dumbass.

And now use the machine like you should.

I decide to go for it in one pass, so I set it up, and get the Mystery Oil out.

I also added a "Scosh" to allow for tool flexing.

 

[Runs With Scissors]

Now the secret is out !

(soaking your tools in Heinz tomato juice)

Cheers and keep the great posts coming. I love these watch you build/mod type threads...

Hahahah, I bet that Heinz can is older than me...

 

[Runs With Scissors]

Almost perfect!!!!!! (OK not perfect, but not too bad, gotta take another small pass)

Now to make myself look good, some emery cloth and some OSHA approved lathe work with the file.

Then rinse and repeat, and I have a somewhat shorter version of my original idea.

 

[Runs With Scissors]

Yep.....I am that guy!!!!

My shop, my rules!!!!

I said "Leave the damn chuck key in the tool head"

 

[Runs With Scissors]

Now I gotta drill a hole for the handle to go through.

Off to the mill.

After about 30 minutes of searching I finally find my "round stock centering tool" (I have no idea what it's actually called.)

Then I set up the collets to try and drill a straight hole through round stock.

I originally was going to grind a flat spot to get the drill started, but where's the fun in that.

 

[Runs With Scissors]

Then life happens and I get side tracked....More to come.

 

[mcfarmall]

3 problems I see.

1. Try a tool bit with a 0.030" radius on the tip. Your ⅛" radius bit thins the chip and helps create chatter.
2. Use a 3 jaw chuck.
3. Place a cloth across the bedways when using aluminum oxide cloth for polishing.

304 is fine for general purpose use. 316 is preferred for product contact use as long as you passivate it.

Your centering device is called a fishtail. I prefer to use an edge finder.

 

[Runs With Scissors]

3 problems I see.

1. Try a tool bit with a 0.030" radius on the tip. Your ⅛" radius bit thins the chip and helps create chatter.
2. Use a 3 jaw chuck.
3. Place a cloth across the bedways when using aluminum oxide cloth for polishing.

304 is fine for general purpose use. 316 is preferred for product contact use as long as you passivate it.

Your centering device is called a fishtail. I prefer to use an edge finder.

Thanks for the tips.

Why a 3 jaw? I thought that a 4 jaw was the preferred chuck to use?

Paul

 

[mcfarmall]

Thanks for the tips.

Why a 3 jaw? I thought that a 4 jaw was the preferred chuck to use?

Paul

4 jaw is typically used for irregular workpieces like square stock or something you intentionally want offset such as a cam. I have a 3 jaw that is adjustable. Basically a 3 jaw chuck on an adjustable backing plate.

 

[Runs With Scissors]

4 jaw is typically used for irregular workpieces like square stock or something you intentionally want offset such as a cam. I have a 3 jaw that is adjustable. Basically a 3 jaw chuck on an adjustable backing plate.

Gotcha...I always thought it was for "more accurate" work.

 

[lynnmor]

Gotcha...I always thought it was for "more accurate" work.

If your 3 jaw has too much runout, then the 4 jaw is fine. As you found out, adjusting a 4 jaw takes some patience.

 

[Biker1mike]

Impressive.
If you worked for me I would have to say isn't it easier , less expensive, and less time/labor to get out of the damn truck and walk into McD's.
Glad to see you have having fun !!!

 

[Runs With Scissors]

Impressive.
If you worked for me I would have to say isn't it easier , less expensive, and less time/labor to get out of the damn truck and walk into McD's.
Glad to see you have having fun !!!

Thanks.


Hahahaha....Yea, but where's the fun in that?

Actually the dining room for this particular McDonalds doesn't open until 0830, so at 0630 drive thru is the only option.

 

[mcfarmall]

If your 3 jaw has too much runout, then the 4 jaw is fine. As you found out, adjusting a 4 jaw takes some patience.

The adjustable 3 jaws are nice. I got mine down to less than 0.0005" T.I.R. using a dowel pin to touch off.

 

[North Idaho Wolfman]

The real story was the tractor and ROPS was trying to save you from death.
Death of eating at McDonalds!