A Scribe And Indicator Base

M

Mark_f

Registered
Registered
Joined
Jan 16, 2020
Messages
5
I been wanting a scribe and indicator base to use on my granite surface plate. I have one that is very large base and 18" high. It is way too big to use on my 9" X 12" plate. I need a nice small one. Yea.... I know..... I could buy a used one online for $20, but there ain't no fun in that. I'm gonna make one, and it ain't gonna cost no money..... Just a few hours time.
image.jpeg I made these pieces this afternoon. The base is 2 1/2" square .... a piece of nice cast iron left over from the work head I am making. I milled a "V" in the bottom, a slot in the top , and a notch in the front.

image.jpeg
image.jpeg
image.jpeg This is way it looks like assembled. The clamp will hold a post made from .375" drill rod. The pin is not inserted all the way because I have to put it together and take it apart many times during the build. There will be a little spring in the front of the adjustment bar and a thumbscrew in the rear. I still have to do that. I also will put four push pins, one in each corner. Lastly , I will scrape the bottom VERY flat.

..... More to come.
 
Very nice. Love the brass. I have had to make a few brass parts for some surface gauges I've gotten that were missing parts. Always thought the brass looked great with them.
 
Using cast iron as an indicator base is not a good idea. It will eventually become charged with grit and will nicely lap holes in your granite surface plate. What you can do is to apply small dots of teflon tape to the bottom (three places preferably). Replace as necessary.

Gene
 
easymike29 said:
Using cast iron as an indicator base is not a good idea. It will eventually become charged with grit and will nicely lap holes in your granite surface plate. What you can do is to apply small dots of teflon tape to the bottom (three places preferably). Replace as necessary.

Gene
Click to expand...
I don't know why...... The large one I have is a brand name and it is cast iron base. I have a couple indicator bases made of cast iron. I always clean the bottom surface before I use them to make sure they set flat. A tiny piece of debri makes a big difference. ( I'm not exactly sure what you mean by "charged" with grit).
 
I think it looks great so far, Mark. Looking forward to future installments on your progress!
 
If one keeps the gage base and his surface plate clean, there should be no problem with the base picking up grit. I always clean my surface plate and indicator base before using.
 
The brand name indicator bases, (Starret, Lufkin) such as you are making, Mark, are case hardened, not sure of the material, but they have the beautiful colors from case hardening on them.
 
I understand what you are saying.... But that is not even in the same zip code as this. You put fine grit on a lapping plate and rub a part around A WHOLE LOT.... In fact much more than this indicator base will slide on the granite plate in mine and my kids lifetime. I have the bottom polished almost to a mirror finish. I'm down to 1200 grit now. I clean my plate and anything that gets used on it before I use it. This base , as smooth as it is , skates really easy and there is no pressure. This is not a problem. In fact , it is no more of a problem than if I had made it from a steel block.
 
You must log in or register to reply here.
Back
Top