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What indicators are needed for scraping?

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expressline99

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#1
OK guys what types of dial indicators and or gauges will be absolutely needed to measure for my lathe scraping surfaces. The ways and dovetails etc. I've got a flexible dial indicator stand on the way. It's not a NOGA...I didn't get on that train yet.



Paul
 

Uglydog

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#2
Have you picked up a copy of Connelys scraping book, and Schlesinger or Burley?
Machine tool geometry is a puzzle. And great fun. (on edit: huge heaps of great fun...)
Albeit lots of work both mentally and physically.
I believe you will find free digital copies of the above texts here at HM. Although my preference is hard copy.
Worth reading before you start spending cash.
Investment in quantitative assessment tools is endless, and expensive.
However, qualitative assessments might very likely be enough to meet the tolerance that most of us need.
Please note that I have a history of driving myself nuts trying to make a clapped out mill into a jig bore.

Daryl
MN
 

woodchucker

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#3
Scraping is not done with an indicator.
It is done with a reference surface and a indicator applied to the surface.
 

4gsr

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#4
A depth mic is good for checking for amount of wear from a reference surface. As for dial indicators, they are not much use for use during scraping and fitting process. All the indicator is going to tell you is if you have any wear in the slides before you tear down your lathe for example. If this is what you are after, get one that reads in .0005" increments. an indicator that reads any finer than this will drive you nuts trying to get accurate readings out of it. In fact, until recently, I've always used .001" reading indicator!

You already bought a surface plate. Have you bought a scraped straight edge like a camel back type? You going to need this along with all of the other tools needed to scrape with.
 
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Ulma Doctor

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#5
IMO, these will all help!

A set of parallels (to indicate from)
Gauge blocks (to indicate from)
Feeler gauges from.001" to .030" (measures clearances)
Flashlight (determines general flatness of stuff against a surface plate)
PPI gauge (1x1 hollow square)(has radius gauge integral to the construction)
Dial indicator or test indicator (to determine wear and inspect finished work)
There maybe more , but that's what I got for now!!!:)
 

expressline99

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#6
Have you picked up a copy of Connelys scraping book, and Schlesinger or Burley?
Machine tool geometry is a puzzle. And great fun. (on edit: huge heaps of great fun...)
Albeit lots of work both mentally and physically.
I believe you will find free digital copies of the above texts here at HM. Although my preference is hard copy.
Worth reading before you start spending cash.
Investment in quantitative assessment tools is endless, and expensive.
However, qualitative assessments might very likely be enough to meet the tolerance that most of us need.
Please note that I have a history of driving myself nuts trying to make a clapped out mill into a jig bore.

Daryl
MN
Oh 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
 

expressline99

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#7
Scraping is not done with an indicator.
It is done with a reference surface and a indicator applied to the surface.
Scraping technique is not in question here. I'm asking about equipment that people find useful doing this.
I'm threshing ideas as I move along ahead of time.
 

expressline99

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#8
A depth mic is good for checking for amount of wear from a reference surface. As for dial indicators, they are not much use for use during scraping and fitting process. All the indicator is going to tell you is if you have any wear in the slides before you tear down your lathe for example. If this is what you are after, get one that reads in .0005" increments. an indicator that reads any finer than this will drive you nuts trying to get accurate readings out of it. In fact, until recently, I've always used .001" reading indicator!

You already bought a surface plate. Have you bought a scraped straight edge like a camel back type? You going to need this along with all of the other tools needed to scrape with.
Great that was what I was after. I was wondering if a half a tenth is what I needed. But the style is also something I was wondering. Since there are dials with pivoting heads etc.

The straight edges I am going to make as the first few projects before getting to the machines. I have all the cast iron needed to make these. So that's the plan.
My level showed up today in multiple parts so that's a little bit of a let down. But the stand isn't welded up yet so I've got some time.
Not to worry I'm following everyone's advice Nothing will be taken apart until I've had some practice and made the straight edges.
 

expressline99

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#9
IMO, these will all help!

A set of parallels (to indicate from)
Gauge blocks (to indicate from)
Feeler gauges from.001" to .030" (measures clearances)
Flashlight (determines general flatness of stuff against a surface plate)
PPI gauge (1x1 hollow square)(has radius gauge integral to the construction)
Dial indicator or test indicator (to determine wear and inspect finished work)
There maybe more , but that's what I got for now!!!:)
Thanks Mike! I see a couple of things to add to the list. I was planning to get a PPI gauge. Just haven't searched for one yet.
At least those are simple. If they can mess that up I'd be surprised!
 

4gsr

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#12
I should buy one. :) Too many projects already!
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. :rolleyes: I don't remember the radius sizes off hand.
 

4gsr

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#13
Oh 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
Here's the link to a copy of Schlesinger's book on Machine Tool Inspection

http://www.hobby-machinist.com/threads/testing-machine-tools-burley-schleshinger.41803/

But don't get all hung up in all of the tight tolerance requirements for new machine tools. Even in rebuilding machines, it takes a great deal of time in scraping and precision instruments to accomplish. And I doubt most of us can recondition our worn out machines to this standard. It is something to shoot for when reconditioning critical components. We can get them darn close!

Ken
 

Rex Walters

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#14
I was wondering if a half a tenth is what I needed.
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.

The tenths indicator is so nervous and fiddly in use that it's annoying, but it is sometimes useful (for measuring the depth of individual scrape marks, for example).

A half-thou indicator seems like it would be ideal to me, though I don't own one. You could still interpolate between divisions to estimate to one or two tenths, but the needle wouldn't bounce around quite as much as an actual tenths indicator, making it much easier to use.

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
 

4gsr

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#15
.......................
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
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.
 

expressline99

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#17
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

OK so opinions on which models of .0005 dials I should choose from? Figure I have $150 to get a decent one and I have an adjustable arm noga knock off base to put it on.

The surface gage I'm totally up in the air on knowing what to get. They look really simple to me but I'm sure there are plenty of differences in qualities.

Are the dials usually just pin or lever? Or are there combinations? Where the tips can be changed?

Paul
 

Rex Walters

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#18
Figure I have $150 to get a decent one and I have an adjustable arm noga knock off base to put it on.
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.
 

Rex Walters

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#19
For your budget I'd go with the SPI from MSC myself.
FWIW, I just ordered one of those 0.03" travel, 0.0005" resolution DTIs from SPI for myself.

$65 was just too good a price to pass up.

I still want a good Interrapid, though.
--
Rex
 

expressline99

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#20
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.
I'm ordering one of the SPIs from MSC. Those surface gages are more than $20.00 how much is the max to pay? Looks like new they are over $200?
Paul
 

expressline99

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#22
I bought someone's 57a with 2 spindles. I'm sure that'll be fine. How much are those king ways? I don't think I can get ken to build me a trolley for my lathe measuring... :(

Kinda wish Bob would chime in. I must have done something ;)


Paul
 

expressline99

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#25
So far I've collected:
DSCN5962.JPG DSCN5963.JPG DSCN5964.JPG DSCN5966.JPG DSCN5967.JPG

For gauge blocks...there seem to be a million of them....?
 

Rex Walters

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#26
Congrats. For general setup work, you might be better off with pin gauges and round spacer blocks rather than actual gauge blocks. I also find an angle block set more generally useful than a sine bar and gage blocks.

Certified gage blocks are very expensive and unless you need to make very high accuracy interchangeable parts, somewhat overkill for hobbyists like myself.

Pin gages are great for both measuring holes (you can put two of them in a hole for measuring diameters, by the way -- you don't need a pin the exact size of the hole you're measuring). They are equally useful for measuring or setting the separation between two parallel surfaces. I find it useful having pin gages up to 0.5" but it depends on the type of work you do.

Whee. It's fun spending your money. :)
--
Rex
 

4gsr

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#27
For machine rebuilding/reconditioning, you do not need gage blocks at all. Just as Rex mentioned above. A good set of 1-2-3 blocks can be handy at times, once in a while two sets!
I notice the little bitty set of feeler gages in your last picture. They might get you by in the beginning but you're going to need others, too. I've always had the 12" long feeler gage leaves they call them. I have them in thicknesses from 0.0005" all the way up to 0.025". My "go to" sizes I use the most is 0.001", 0.002", 0.003", 0.004", 0.005" in checking fit. I start with 0.001" and work up. This will give me a idea of how much material I need to remove to make things flat again. This also tells me what to hand scrape and what goes to the mill for remachining flat again. My rule of thumb is, if a 0.005" or larger feeler goes, it goes to the mill or planer for remachining. Not to say it could be scraped to flatness again. It turns into a lot of work to get there.

Feeler gages are also used to fit up gibs and hold down plates at final assembly on machine components, too. I won't go into details on that now, as the subject comes up I'll chime in and give my two bits worth on it.
 

expressline99

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#28
For machine rebuilding/reconditioning, you do not need gage blocks at all. Just as Rex mentioned above. A good set of 1-2-3 blocks can be handy at times, once in a while two sets!
I notice the little bitty set of feeler gages in your last picture. They might get you by in the beginning but you're going to need others, too. I've always had the 12" long feeler gage leaves they call them. I have them in thicknesses from 0.0005" all the way up to 0.025". My "go to" sizes I use the most is 0.001", 0.002", 0.003", 0.004", 0.005" in checking fit. I start with 0.001" and work up. This will give me a idea of how much material I need to remove to make things flat again. This also tells me what to hand scrape and what goes to the mill for remachining flat again. My rule of thumb is, if a 0.005" or larger feeler goes, it goes to the mill or planer for remachining. Not to say it could be scraped to flatness again. It turns into a lot of work to get there.

Feeler gages are also used to fit up gibs and hold down plates at final assembly on machine components, too. I won't go into details on that now, as the subject comes up I'll chime in and give my two bits worth on it.
As inexpensive as the gauges are I will get those right away. Do I need bent or straight? Or do you use both?

The little set I bought was under $15.00 so a tiny drop in all of this collecting /prep.

Gage blocks ordered...set of 4. :) weeeeeeeeeeee
I hope you guys don't get tired of me before I get to the actual work! :)



Paul
 

expressline99

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#29
Congrats. For general setup work, you might be better off with pin gauges and round spacer blocks rather than actual gauge blocks. I also find an angle block set more generally useful than a sine bar and gage blocks.

Certified gage blocks are very expensive and unless you need to make very high accuracy interchangeable parts, somewhat overkill for hobbyists like myself.

Pin gages are great for both measuring holes (you can put two of them in a hole for measuring diameters, by the way -- you don't need a pin the exact size of the hole you're measuring). They are equally useful for measuring or setting the separation between two parallel surfaces. I find it useful having pin gages up to 0.5" but it depends on the type of work you do.

Whee. It's fun spending your money. :)
--
Rex
Hey It's fun for me too. I really enjoy this part. :D
How do I get a snug for this SPI TDI you had me buy? >:)


Paul
 

4gsr

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#30
................................ Do I need bent or straight? Or do you use both?

.....................................Paul
Bent?
Get a 12" long .001" feeler strip and you'll find out how flexible it is. It just flops around! No, you do not need the bent one's people out there offer.
Remember, most all of the feeler gage sets out there do not come with a .001" feeler. Usually .0015" is the smallest. You need a .001" feeler!

Here's what I'm referring to.

http://www.ebay.com/itm/STARRETT-66...915108?hash=item58e5772e24:g:ET0AAOSwuxFYt02h

http://www.ebay.com/itm/20-Piece-0-...167398?hash=item54458db3e6:g:PvAAAOSwuLZY4hP0

http://www.ebay.com/itm/SPI-91-345-...203028?hash=item2cc2967bd4:g:4iQAAOSw6YtZOZEh


Ken
 
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