# Machining Cebloplast?



## Dan_F (Mar 21, 2012)

I've seen several references to difficulty drilling, turning cebloplast material, but no specifics. So, what are recommended drilling speeds so that I don't waste any of this precious material? Any other tips about it?

Thanks, 

Dan


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## ed4copies (Mar 21, 2012)

I never had any trouble turning it.  Have done so with roughing gouges, as well as a skew.

Drilling is a different story.  If it gets hot, it can melt.  This was the first material that I learned to use water in the hole--now I would add a little dishsoap.  But, I have not turned it in a long time so many others will have more knowledge than I.


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## Dan_F (Mar 21, 2012)

I've seen folks say to "go slow", but that means different things to different people. While we're on the topic, I have the same questions about ebonite. 

Dan


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## hewunch (Mar 21, 2012)

Slow drill speed, clear often, use water to cool the bit. Here is what happens. Instead of slicing the material away in pretty ribbons or even dust. The material melts. And when it melts, it covers your drill bit and acts like epoxy. The only way to get your drill bit out, is to bust the material.


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## dgscott (Mar 21, 2012)

SLOW. Real slow. Make sure your bits are sharp and that you only drill a liiittttle bit at a time -- give the material and the bit plenty of time to cool as its melting point is very low. Lubrication helps, but slow is the key.

The results are worth the time it takes.
Doug


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## Curly (Mar 21, 2012)

*I've only made 1 pen of it so take my advice with that in mind.*

I agree with what Doug said. I drilled on the metal lathe a 200 rpm and wet the hole and drill with cooking oil every time I pulled the drill bit out (.100" to .200" at a time). Turning on the metal lathe was 360  and 400 rpm and very slow feed with light cuts with a sharp HSS cutter. On the wood lathe was up to 1000 rpm and very light cuts with a sharp 1/4" bowl gouge. I sanded from 320 to 600 dry and then buffed with the Beall wheels. I was happy with the way it came out.


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## 1080Wayne (Mar 21, 2012)

If using a drill press , slowest speed , sharp bit , drill 1/8 inch , back out , fill hole with water , and keep repeating the process until done . On lathe , very sharp tool , thin cuts , allow blank to cool a bit between passes .


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## Dan_F (Mar 21, 2012)

How slow - in terms of RPM?

Dan


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## Dan_F (Mar 21, 2012)

Curly said:


> I agree with what Doug said. I drilled on the metal lathe a 200 rpm and wet the hole and drill with cooking oil every time I pulled the drill bit out (.100" to .200" at a time). Turning on the metal lathe was 360  and 400 rpm and very slow feed with light cuts with a sharp HSS cutter. On the wood lathe was up to 1000 rpm and very light cuts with a sharp 1/4" bowl gouge. I sanded from 320 to 600 dry and then buffed with the Beall wheels. I was happy with the way it came out.



Thanks, those were the specifics I was looking for!

Can anyone give the same sort of guidance or ebonite too, which I gather is not nearly as demanding as the Cebloplast.

Can a moderator merge these duplicate threads?

Dan


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## bitshird (Mar 21, 2012)

DAn I drill it with say a 12.5 mm bit at around 450 RPM, drill a 1/4 inch or so then cool it. I usually use DNA since it has a very quick evaporation and heat transfer I just keep it in a squirt bottle and position my drill flutes so I can run the DNA right into the hole, Just clear the shavings which are weird as the devil, they actually will crumble into a powder.
Nice Material. just a bear to drill, EASY to turn though, it's just getting the hole in that is nerve wracking.


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## Gilrock (Mar 21, 2012)

I was using Cebloplast for the second pen I was working on.  I found that I could only go 1/8" before I had too much debris and heat buildup.  I wasn't happy with the heat buildup when I tried going 3/16" or deeper before cooling.  I kept a low profile paint bucket filled with water sitting on the lathe below the work and used a syringe to blow water in the hole and on the drill bit.  Going only 1/8" and using water the bit never gets hot at all.  If you retract the bit and it burns to touch it that's too hot...it should only feel warm.  Also I didn't like drilling at low speed....I tried whatever my lowest setting was near ~400-450 and I liked how the bit was behaving better when I moved the belt over to the ~800-850 setting.


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## Dan_F (Mar 21, 2012)

Thanks for all of the suggestions!

Dan


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## drgoretex (Mar 22, 2012)

Not to sound too much like a parrot, "go slow".  

But what I'd add is a tip I find very useful, and that's to have a rag soaked in cold water handy, drill only about a half cm at a time, pull out the drill and cool it with the rag.  Seems to work very well for me.

Ken


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## Robert111 (Mar 28, 2012)

I drill ceblo and invisavue at about 250 on the wood lathe, slow advances, squirting water in the hole about every 15 seconds. Always works.

Everything else I drill at 350--I'm just not in that much of a hurry, I guess.


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## Texatdurango (Mar 28, 2012)

Gilrock said:


> I was using Cebloplast for the second pen I was working on.  I found that I could only go 1/8" before I had too much debris and heat buildup.  I wasn't happy with the heat buildup when I tried going 3/16" or deeper before cooling.  I kept a low profile paint bucket filled with water sitting on the lathe below the work and used a syringe to blow water in the hole and on the drill bit.  Going only 1/8" and using water the bit never gets hot at all. * If you retract the bit and it burns to touch it that's too hot...it should only feel warm*.  Also I didn't like drilling at low speed....I tried whatever my lowest setting was near ~400-450 and I liked how the bit was behaving better when I moved the belt over to the ~800-850 setting.



I think Gil has given the best advice so far.  While it's obvious to drill at a slower speed to keep from building up heat, *the* *hot drill bit is the culprit* whether you drill slow or fast so I wouldn't get hung up on RPM's.  You can spray all the coolant you want and drill at a snails pace but if you are starting out with a hot drill bit, you're asking for trouble!

I pay more attention to the drill bit temperature than how fast I'm drilling.  When I retract the bit I let it cool down to room temp, not just warm, before going back in with it because "warm" gets hot quick! :biggrin:

Ebonite is just as sensitive to drilling heat build up as many acrylics and some dense woods so it's just good practice to learn to drill without building up heat regardless of what material you are drilling.  If you retract a bit after drilling and it's hot... let it cool down, don't just squirt it with water or oil and dive back in!  I found that cutting and sanding ebonite too fast or too much pressure can actually scorch the rubber and one you've done that, it's hard to get a smooth glossy finish.  If you're cutting or sanding and smell burning rubber, slow down and ease up on the cutting tool force or sanding pressure!

That's my 3 pennies worth.


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## johncrane (Mar 28, 2012)

I spray the drill and the hole with DNA,i use a plastic container on the lathe bed too catch the curly bits and the DNA drips then later strain the DNA from the curly bits and reuse the DNA,


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## Dan_F (Mar 28, 2012)

George and John --- Thanks for the additional info, especially George for addressing the ebonite question. 

I think a bucket of ice water and a washcloth might hurry things along, assuming that the drill wouldn't get so hot that it would pose a problem with the rapid quenching, and that the washcloth could be wrapped around both the drill and the blank (not while moving) to remove heat more quickly. 

I like the DNA example for the same reason, evaporation would remove heat more quickly. 

Dan


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