Thank You Pete!
i'm not sure when the class is going to happen, but i'm looking forward to it.
i'm considering having my own party again and inviting guests....:grin:
 
Hmmm.
I gonna have to look, where is Tracy California??......

Daryl
MN
 
Ulma Doctor Hinging?
I have noticed differing ways parts move when swinging ( rotating ) them to check that the centers aren't high.
Never thought to do this on the blue. Will give it a try when possible.
That may have sped things up a lot when scraping the gibbs flat before fitting them.
 
Ulma Doctor Hinging?
I have noticed differing ways parts move when swinging ( rotating ) them to check that the centers aren't high.
Never thought to do this on the blue. Will give it a try when possible.
That may have sped things up a lot when scraping the gibbs flat before fitting them.

Hi Tertiayjim,
hinging is a way of testing the bearing of the scraped piece on a surface plate.
a properly hinged part will hinge at about a 1/3 from the end, on both ends.
you won't really need to have blue on the plate to do it though, it can be hinged on a bare surface plate.
another method i use, i learned form youtube video's is the-Tap,
or Thump as i like to call it-
you'll simply lay the intended scraping victim on the surface plate, and give a nice solid thump with your forefinger on the piece in the corners of the piece.
if the part is flat all you will hear is the thump of your finger.
if the part is not flat, in reference to your surface plate, there will be a slight ring that will be heard.

i hope the info is helpful to someone :)
 
Thanks Dr.
Am learning from books, U-tube, the posts of others, and experience.
I learn more from my mistakes than anything else. LOL
Working on my china lathe has been easy in that even a poor job is far superior to the factory work.
Components no longer rattle when tapped and rigidity is greatly increased.
Machining gibbs has been a pain in the tookus. So much to learn...
 
Now that you have the first side roughed go ahead and rough in the dovetail side before finishing it as the first side will likely move after roughing in the second side. Also what is your scraping depth remember Rich's 2-4 tenths deep and percent contact rules Bob
 
Thanks for reading Bob!
it's funny that you said to go to the dovetail next...
i already started the dovetail but did not post any updates yet.
my hand roughing scrapes may be a little deeper than 4 tenths, but thanks for the reminder!
i haven't really started scraping for points yet, i'm just trying to achieve proper bearing and hinging first.
all the pointers are greatly appreciated :)
 
Hinging? Never really thought about it, but in a lifetime of fitting things with
files and grinders, I've been doing it for years. BLJHB.
 
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