An exercise in frustration, being a hobby machinist

[Janderso]

I know I’m supposed to make mistakes, I do, all the time.
I’m making some clamps like the Kant-Twist variety.
I am very careful, this is a simple part but it needs to be accurate to +0 -.002”.
I need two pivots, the first one is spot on, OK, piece of cake. I measure one final time, dial in .004” and I turn .010”.
One thing about this project, I’ve never had to turn to a shoulder with this accuracy.
I have to walk away for the rest of the day…….. maybe.
I need to remind myself, it’s OK, you don’t know what you are doing and look what you made. = scrap?

 

[Doug Gray]

Hang in there Jeff. You'll get it done.

 

[Bob Korves]

We have all been there, Jeff. "I cut it 3 times and it's STILL too small..."

 

[ericc]

Will the clamp still work with the undersized tenon? I was wondering if it would bind somehow.

 

[Larry$]

Bet it will work anyhow. How was the .002 tolerance determined?

 

[francist]

If it's the shoulder to shoulder distance that's off, an appropriate shim would probably allow the piece to function.

 

[MrWhoopee]

Bet it will work anyhow. How was the .002 tolerance determined?

Probably by a freshman engineer (who finally got to ride in front and blow the whistle).

 

[MrWhoopee]

Lucky for you those are some of the simplest parts in the assembly. Wouldn't want to scrap the side plates.

 

[Ulma Doctor]

I have scrapped more parts than I want to admit, but it has taught me to sneak up on critical dimension.
Even though i’m a proficient welder, it’s still easier to take material off rather than put it on.
I often divide the final cuts or make .001” cuts until i hit the mark.
Since adoption of the practice, there is a lot less cussing and less scrapped parts ,
As you get to know your machines, you are going to know what you can get away with and where you need to slow down

If this sport was easy, everyone would be doing it!!!
Chin up

 

[Aukai]

Those knob graduations, plus any backlash(if not taken out)drive me crazy, I'm still practicing with the DRO, it ain't infallible either.
Each part of the line on the knob is wort 5 tenths front of the line, the middle of the line, and the back side of the line it seems