# Machinable Non Compressible Insultator



## Robert LaLonde (Nov 16, 2017)

I've decided I need to make some electrical tool height setters for my machines with a fairly small foot print.  I've figure out my design so they will have a lot of over travel and good repeatability, but I am wondering about the anvil or touch surface.  The analog indicator type I am using now seem to have a steel surface, but they are softer than the tools and they will ding fairly easily if you make a mistake.  Because I do a lot of flood machining I was thinking stainless might be the ticket.  304 for the body, and 303 or 416L for the anvil with an acetal insulator.  A harder machinable insulator might be better, but I am not sure what.

Definitely NOT something like HDPE since its compressible, and spring pressure over time might cause it to extrude and drift. I don't really have room for an off material setter to to be used all the time.  Adding soft buttons and macros to semi automate the tool height set is pretty easy for my controls.  It would improve my machine times, and reduce my necessity to deburr between tool changes more easily creating consistent parts.


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## Nogoingback (Nov 16, 2017)

It's not clear to me what the part looks like, but lexan is tough and has very good insulating qualities.


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## Robert LaLonde (Nov 16, 2017)

Polycarbonate might be a good choice, I'll have to research it.  

Cylinder inside a cylinder.  Doesn't matter.  If it works I'll write it up.  If it doesn't work out I'll whine real loud about it.


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## David S (Nov 16, 2017)

Anodized aluminum is an electrical insulator.

David


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## mksj (Nov 16, 2017)

I use phenolic CE grade canvas sheet, but it also comes in glass filled versions called G10 both in rod and sheet. It is very dense and not pliable, the CE is for electrical, I make control boards with it. I have some 1/4" sheet remnants of the canvas CE grade if you want a piece to play with. Send me your address in a PM and I will a ship a piece in an envelope, otherwise some G10 is even denser and is available online.


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## Robert LaLonde (Nov 16, 2017)

Nogoingback said:


> It's not clear to me what the part looks like, but lexan is tough and has very good insulating qualities.



Seems that polycarbonate can cold flow like many other plastics over time.  Research research research.  LOL.  Here is a rough draft of the idea.  Shorts to frame ground when a tool touches it.  Can be made with a huge safety over travel.  A typical indicator type height setter only has 0.1 to 0.2 over travel usually.

I'm going to give phenolic a shot.  If that doesn't cut it then Macor may be next.  Phenolic is cheap though and Macor is expensive.






Typically simple probes and electronic height setters are made with a ring of six gold plated round beads, and the core is an insulator that holds three gold plates pins in a star configuration that short between the gold balls in pairs.  Any movement of the probe or table attached to the core breaks the contact.  Its a better design than mine because it fails safe.  ie:  If it fails the circuit is broken and the machine thinks its already touching so it doesn't move.  If mine fails it will drive the cutter into the height setter.  If I have a broken circuit somewhere with this simpler design the machine won't know.   The extra over travel will give me time to hit the e-stop or the feedhold though.

The piston will likely get threaded on top and a table will be mounted to reduce coolant and chip contamination.

If you look at the images you will see a plug that holds it all together.  During machining a spacer is used instead of a spring to hold the piston firmly against the insulator so the end of the piton (or the table) can be machined flat relative to the base of the setter.


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## RJSakowski (Nov 16, 2017)

McMaster Carr sells machinable ceramic


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## Robert LaLonde (Nov 16, 2017)

RJSakowski said:


> McMaster Carr sells machinable ceramic



YES THEY DO!  $54 for a 3/4" rod 3" long is a bit much though.  I use phenolic handles on lead casting molds that are about that size for a little over a buck.  I'm going to give phenolic a try.  Another member here said they would send me a piece of a slightly different phenolic than the handles I use too.


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## Nogoingback (Nov 17, 2017)

Is phenolic resistant to liquids like coolant and oils?


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## Robert LaLonde (Nov 17, 2017)

Nogoingback said:


> Is phenolic resistant to liquids like coolant and oils?



Its used for making gears, bushing, and rollers so it should be able to handle basic oils.  I guess I'll find out.  Can't speak for the SC520 with distilled water for my flood coolant, but I can drop Master Chemical an email and find out.  They are usually pretty responsive.  The thing is if more than cursory crap gets in a height setter it has to be taken apart, cleaned, and readjusted anyway as it will gum up.

These are not to be permanently mounted for fully automated tool changes.  In fact if I was setup for fully automated tool changes I would not need them at all.  Just enter all the tool heights in the tool table.


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## DHarris (Nov 17, 2017)

Don't know what they are actually made of, but could you use an old hockey puck - should be cheap / plentiful and I've heard easy to work with??


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## Wreck™Wreck (Nov 17, 2017)

Machinable ceramics such as Corning Macor®

http://ceramicproductsinc.com/macor.html


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## pdentrem (Nov 17, 2017)

Bakelite or phenolic will work just fine. I also use the G10 boards at 0.125" thick. Very dense and heavy. I use the scraps for shims under heavy machinery and even as separators between the ground/concrete and wood pillars to stop water wicking up the wood.
Pierre


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## Uglydog (Nov 17, 2017)

I had that mica rod which on the consul of HM feedback I decided not to use on a project. 
Maybe 3inch round. Maybe 36inch long.
If interested I can confirm next week at my steel supplier both diameter and cost.
You could get however little or much you wanted. 

Daryl
MN


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## Robert LaLonde (Nov 17, 2017)

Wreck™Wreck said:


> Machinable ceramics such as Corning Macor®
> 
> http://ceramicproductsinc.com/macor.html



Yep, and if you compare like sizes (I used 3/4inch diameter for a baseline for comparing materials) its over $10 per inch



pdentrem said:


> Bakelite or phenolic will work just fine. I also use the G10 boards at 0.125" thick. Very dense and heavy. I use the scraps for shims under heavy machinery and even as separators between the ground/concrete and wood pillars to stop water wicking up the wood.
> Pierre



Yeah, and its pretty cheap too.  At my comparison size its less than 62 cents per inch.  Even cheaper if you repurpose mass produced phenolic products.  

http://www.usplastic.com/catalog/it...erm=4580221844135631&utm_content=All Products


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## British Steel (Nov 17, 2017)

DuPont Corian offcuts from the kitchen fitters are non-conductive and harder than a quality chef's knife... cuttable with carbide tooling (kitchen fitters work them with routers)

Dave H  (the other one)


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## Robert LaLonde (Nov 17, 2017)

British Steel said:


> DuPont Corian offcuts from the kitchen fitters are non-conductive and harder than a quality chef's knife... cuttable with carbide tooling (kitchen fitters work them with routers)
> 
> Dave H  (the other one)


Dang-It!  I know where one of the counter top companies is dumping their broken, miscuts, and drops too.  Unfortunately all they seem to be installing right now is granite.  I have a couple cool pieces of granite to play with in the shop now.


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## samthedog (Nov 18, 2017)

pdentrem said:


> Bakelite or phenolic will work just fine. I also use the G10 boards at 0.125" thick. Very dense and heavy. I use the scraps for shims under heavy machinery and even as separators between the ground/concrete and wood pillars to stop water wicking up the wood.
> Pierre



Phenolic is a great material. Stable, machinable and can withstand compression. Just be careful when machining and avoid breathing the dust. 

Paul.


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## Robert LaLonde (Nov 18, 2017)

samthedog said:


> Phenolic is a great material. Stable, machinable and can withstand compression. Just be careful when machining and avoid breathing the dust.
> 
> Paul.


That's probably good advice for anything.  Avoid breathing the dust.


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## uncle harry (Nov 18, 2017)

Bob La Londe said:


> Its used for making gears, bushing, and rollers so it should be able to handle basic oils.  I guess I'll find out.  Can't speak for the SC520 with distilled water for my flood coolant, but I can drop Master Chemical an email and find out.  They are usually pretty responsive.  The thing is if more than cursory crap gets in a height setter it has to be taken apart, cleaned, and readjusted anyway as it will gum up.
> 
> These are not to be permanently mounted for fully automated tool changes.  In fact if I was setup for fully automated tool changes I would not need them at all.  Just enter all the tool heights in the tool table.



My first car, a 1950 Chevrolet, had a phenolic timing gear that ran in oil. My Harrison M300 has a phenolic gear in the headstock gear train for feeds & threads.


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## pdentrem (Nov 18, 2017)

They were still using phenolic timing gear in the '90. Particularly the Buick 3.8V6 that we serviced at the dealership. Many Small Block Chev V8s also ran the large cam gear which was phenolic. The reason was for lower chain noise. 
Pierre


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## pdentrem (Nov 18, 2017)

samthedog said:


> Phenolic is a great material. Stable, machinable and can withstand compression. Just be careful when machining and avoid breathing the dust.
> 
> Paul.



My lady and I were in Nordagutu earlier this summer visiting family.
Pierre


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## Wreck™Wreck (Nov 18, 2017)

Bob La Londe said:


> Yep, and if you compare like sizes (I used 3/4inch diameter for a baseline for comparing materials) its over $10 per inch



You failed to add "cheapest possible" machinable non compressible insulator, glass and granite are also machinable though not cheaply.


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## Robert LaLonde (Nov 18, 2017)

Wreck™Wreck said:


> You failed to add "cheapest possible" machinable non compressible insulator, glass and granite are also machinable though not cheaply.



LOL.  Cheapest possible?  No I am sure I can find something cheaper.  Glass and granite have to be ground and polished.  While grinding is part of machining the clarification should be easily machinable.  I'm always amused when people are spending somebody else's money they don't care how much it costs.  LOL.


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## Wreck™Wreck (Nov 18, 2017)

I can't spend your money only you and possibly your Wife can do that (-:

You inquired about a material for a specific application in a measuring tool and I supplied one that would work well and is not over the top expensive unless your threshold of expensive is more then $0


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## Robert LaLonde (Nov 18, 2017)

Wreck™Wreck said:


> I can't spend your money only you and possibly your Wife can do that (-:
> 
> You inquired about a material for a specific application in a measuring tool and I supplied one that would work well and is not over the top expensive unless your threshold of expensive is more then $0



Thank you for that.  I did look at machinable ceramics.  Now you are just being an obtuse * ____ , but this is the Internet and that is to be expected.  Thank you for your useful suggestion, and to a lesser degree for your less useful suggestion as well. 


_* appropriately and equally insulting, but not vulgar.  _


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## Wreck™Wreck (Nov 18, 2017)

Should I be offended? I am terribly sensitive you know.


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## KBeitz (Sep 20, 2018)

phenolic Table Saw Inserts  sold on E-bay works great for insulators.  


https://www.ebay.com/itm/Leecraft-D...m=292701468313&_trksid=p2047675.c100005.m1851


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