- Joined
- Nov 29, 2015
- Messages
- 439
You can easily make the ppi gauge
Dapra sells them
I can scan mine and you can copy it if you were so inclined
I should buy one. Too many projects already!
You can easily make the ppi gauge
Dapra sells them
I can scan mine and you can copy it if you were so inclined
All you need is a card board cutout the the 1" square opening. As for the radii on the gage, select three different size cans of an appropriate diameter to use for a gage to grind your scraper blade radius to. I don't remember the radius sizes off hand.I should buy one. Too many projects already!
Here's the link to a copy of Schlesinger's book on Machine Tool InspectionOh yes I'm halfway through Connelys book. Haven't seen Schlesinger or Burley yet! Will have to check into it.
The Assessment tools are what I'm after!
Thanks, Paul
I was wondering if a half a tenth is what I needed.
Rex, you think a tenths reading indicator is nervous and fiddly, which you are correct, try a 50 millionths reading indicator. You literally can't keep the needle from moving. The fine adjustments you find on a indicator setup are almost totally useless. And even the fine adjustments on height gages are hard to use with the more sensitive dial indicators. I hate to try a digital indicator on a stand with a fine adjustment. I have a old analytical electronic indicator that goes down to 50 millionths. The electronics smooth out the signal so the needle doesn't bounce around so bad........................
The tenths indicator is so nervous and fiddly in use that it's annoying, ..............
In addition to a mag base and adjustable arm, you'll definitely want a surface gage and snug to fit your DTI (those are relatively cheap).
Regards,
--
Rex
Try a 50 millionths reading indicator. You literally can't keep the needle from moving.
I believe (hope) you're saying you're relieved you don't have to buy an indicator that reads to half a tenth (0.00005" or 50 millionths of an inch). Such things do exist, even mechanical indicators, but they aren't cheap for darn sure.
Ken was saying to get an indicator with divisions every 5 tenths (two divisions every thou). I strongly agree that such an indicator is ideal (though still pricey).
I agree with everything Ken and Mike suggested.
I know next to nothing about machine reconditioning, but would still recommend my route of spending a few weeks learning how to scrape cast iron parts flat, parallel, and square first, before trying any reconditioning. It's puzzling enough to understand why blue-ups sometimes seem to change at random even with simple rectangular parts. Until you can reliably step scrape a part parallel and square within a a couple tenths over, say six or ten inches, I wouldn't attempt anything too serious on your lathe.
Measuring how much scraping is required is an excellent (and non-destructive!) thing to try in the meantime, though. It's instructive to see how well your measurements repeat, and how much they might vary from day to day. This video shows something Richard King's dad invented, called the "king-way" tool for measuring machine tool ways.
I've had my eye on this indicator for a while: http://a.co/bWpLsNS even though I have both a 0.001" and 0.0001" Mitsutoyo DTI. My DTIs require you to flip a switch to read with the lever traveling in the other direction (i.e. one setting when pushing the lever, the other when pulling) -- I think the interrapid style indicators eliminate the switch.
In addition to a mag base and adjustable arm, you'll definitely want a surface gage and snug to fit your DTI (those are relatively cheap).
Regards,
--
Rex
Figure I have $150 to get a decent one and I have an adjustable arm noga knock off base to put it on.
For your budget I'd go with the SPI from MSC myself.
Ooh. Nothing more fun than spending other people's money. ;-)
These should help:
Amazon
MSC
For your budget I'd go with the SPI from MSC myself.
Variables are the quality and jeweling, mounting options, lever arm options, face color, and travel distance.
You don't need much travel distance (0.015" is plenty).
Look for a used Starrett surface gage on ebay -- shouldn't cost you more than twenty bucks or so. Small ones are model 56 or 57, large ones model 257.