[greybeard]

"A rose by any other name would smell as sweet"

These old eyes read no fundamental development in the change of name from Epoxy/whatever to Mineral Casting

John

[castinite]

I find the conversations in this section very interesting and appreciate everyone's comments.
The term mineral casting is commonly used in Europe, where this material is much more common. If I hadn't started a polymer casting company in the US, I am not sure this material would be in use in this country. I actually started three companies and spawned three others. The term polymer concrete is confusing as there are three types of polymer, that are completely different and our type of polymer concrete has no concrete. This confuses people.
The reason for using this material in machine tools and inspection equipment are bascially its vibration dampening and corrosion resistance.
Milling machines and grinding machines using these bases show increased tool life of up to 40%, reducing tooling cost and down time. Inspection equipment, pick and place and optical equipment can operate much more precisely. Eliminating the need to paint saves money and the environment. Polymer castings consume 85% less energy than cast iron castings.

[JohnMcNamara]

Hi Castinite

Just to clarify I was not suggesting that “mineral casting” was different from polymer concrete, epoxy concrete, epoxy granite or any other combination of materials. Only that the name has changed certainly in Europe.

No doubt each manufacturer has developed a proprietary formula, some may well differ.

Using the name “mineral casting” Has some merit, doing away with the need to technically define the contents of your formula. And there is no suggestion of “Plastic”.
Is this another one we can blame on the esteemed marketing guru’s……

There have been several threads recently in this place that suggest that there are only a small number of commercial machines that use the process. Clearly this is not so, there are many, particularly where high accuracy is required.

Not only for machinery; as the image link I posted previously clearly shows.

In fact I suspect that the manufacture of bench tops sinks and other architectural fittings is the place to be for volume production, add to that commercial equipment, chemical processing and the like and the machine tool industry looks rather small.

Another area that astounds me is the Epoxy concrete floor finishing and topping industry. I have a Google alert set for “epoxy concrete”. Nearly every hit is for floor finishing product, hundreds of companies are marketing it.

For the record I am only interested in machine tools.

Cheers

John McNamara

[castinite]

John,

You are correct. Our main product is polymer concrete (epoxy/quartz) castings for machines. We also cast pump bases, highway products and even some synthetic granite countertops. In the US, all the machine base manufacturers use the formulatioins I developed. Same reisn, hardener and aggreates.

[johnohara]

Terry~

What are you casting today?

~John

[castinite]

John,

We are casting machine bases for gear grinding machines, OD grinders, lens grinders, pick and place machines, high speed printers and pump bases. Many of our former customers are either in China or were put out of business because of China, so we are now setting up production there.

We did a lot of high precision drums (18" ID) for optical scanners and the prepress industry, but they are all gone, and we made a lot of chip bonder bases.


Terry

[Steven.ji]

yeah, that waz my idea.....cheap machine.


I have ordered sbr20 rails and sliders from linearmotionbearings(ebay) and i am trying to avoid high cost of epoxy(1 kg 40 usd in croatia)...on another side 1 kg poly cost about 6 usd

is it possible to add strenght to polyester resin?i made few years ago a few subwoofer boxes and door panels for carhifi, so i know a basics of poly and fiber glass...

Woo

The price of epoxy is surprising high in your country!! 40USD/Kg!!!

In China, the price is no more than 5USD/Kg, I think the price will not be so expensive in your country.

If so, you even import epoxy resin from China, I think the cost is much cheaper than in your country.


Steven

[RomanLini]

Woo

The price of epoxy is surprising high in your country!! 40USD/Kg!!!

In China, the price is no more than 5USD/Kg, I think the price will not be so expensive in your country.

If so, you even import epoxy resin from China, I think the cost is much cheaper than in your country.
...

I don't know the type of either "epoxy" but good high adhesion low shrinkage epoxy will be quite expensive and low quality low adhesion high shrinkage polyester resin can be dirt cheap.

It's like comparing prices of "paint" to "paint".

[castinite]

That is correct, you cannot really compare the properties of epoxy and polyester. It is more like comparing stain to paint. Two different products for two different uses. It does depend on the application, but I would never try to use a polyester for any machine base, if you want it to be stable and useful for more than a month.

Terry C

[bugattibuilder]

To the Croatian guy: You are certainly looking in the wrong places. If you need help finding a suitable supplier for your epoxy needs, contact me and I can direct you to some suppliers in your area.

[Steven.ji]

These days, I always wonder it's possible to consider weathering resistance of epoxy granite.

In general, there's big temperature change, air corrasion etc China. For example, there's 40 degree difference in workshop in summer. high humiliation in some area in China.

what about the weathering resistance of epoxy granite?

[castinite]

Steven,

You may recall the statue base outside the hotel in Cleveland that we cast several years ago. It still looks exactly like the surrounding granite, as it did when we cast it. Weather does not get much more variable than in Cleveland.

[Steven.ji]

Yes, I remeber the status. There's no any corrosion.

However, I care about the precision stabiliy. Once the epxoy granite suffer weathering, how about the precisionstability? Especially for super high precision.

[castinite]

We have not done any weathering stability tests as the precision machine bases we make are use in controlled environments. We have confirmed long term stability inside.

Terry C

[JohnMcNamara]

Hi All

A few in here will know I am working with mineral casting. AKA Epoxy granite.

I thought this was a bit off topic for this thread so have been posting here:

Model Engineer

The Worden is a very UK machine in concept

I decided to change the design from sheet metal to Epoxy concrete as a training exercise; the lathe tool grinder will be quite useful so the time is not wasted.

Also note the end castings for this machine. While rather chunky at 50mm thick they are moving parts rather than just base castings (With epoxy low friction bearings integrated into the design)

The machine is very rigid; this is a great medium when you get the hang of it.

Once this machine is complete I plan to get back to the CNC mill I have been working on.

Cheers

John McNamara

[ngg117254]

hi John,

Epoxy base as an execise is OK.

but it may not necessary for a lahte tool grinder.

Ganesan

[JohnMcNamara]

HI ganesan
You Say….
“Epoxy base as an execise is OK.”
“But it may not necessary for a lahte tool grinder”
-----------------------

Firstly the base is only one of four parts it is made from epoxy concrete with steel inserts.

The Cast carriage ends with steel bearing inserts and integrally cast low friction y axis bearings? These are moving parts. Made from Epoxy concrete

Also yet to be built will be the motor base; that includes a cast in place high accuracy threaded nut for the Y axis feed.

Before you dismiss this machine as an “exercise “ think of all the thousands of threads in this post that talk about the minutia of epoxy casting without actually trying to make a real working machine. Real worked out and built machines are pretty rare indeed.

Its one thing to talk about it quite another to actually make something, I chose this simple machine so that anyone in this place that feels like “having a go” may be inspired to start a similar project of their own. If it not this tool then design and build something else.

A litre and a bit of epoxy, some sand and aggregate and a small amount of steel. If you have a suitable motor in stock that you can adapt the whole thing costs around a hundred bucks. Less if you also have the steel in stock.

Also if you study the machine can you not see that it is far superior to the original sheet metal design? With a little ingenuity the design could be adapted to grinding other tools. Thanks to the epoxy castings the machine is superbly rigid. It will not vibrate. Sure I can do a pretty good job “off hand” grinding a High speed steel lathe tool, however when it comes to a threading tool off hand is not quite there in terms of accuracy. Carbide is even more critical in terms of geometry.

The Worden machine is quite popular in England Many people have built them; and there are quite a number of attachments for grinding circular cutters and other tools designed by various people, I bet the epoxy concrete stiffness assists greatly grinding cutters.

The main thing is build something and learn the process.

Cheers

John McNamara

[RotarySMP]

I agree with you John, too much talk and not enough practice. I think the scientific post dealing with optimizing aggregate mix are great, but it is good to see you getting your hands dirty.

EG is on my to do list, but at the moment metal casting is the trip I am on.

I think your Worden base looks excellent (although I preferred the look of the EG before you painted it). You have made a great job of that.

[ckelloug]

John,

I am impressed with your work on the Worden and think you are doing a great job realizing it in E/G. I don't think anyone here should be allowed to detract from that.

In all honesty, most of the theory work I've done and the dozens of sample mixes I've made and ASTM D-790 tests I've performed on those samples are not really germane to the production of a single item like your Worden where exact material performance need not be known. My work is in understanding what materials can be made repeatably to exacting performance standards at minimum cost and knowing what the material properties are. I'm glad to help where I can but I recognize that not everyone likes to watch an exhaustive discussion of material properties and engineering. At this point I tend to save posts for cases where I have actually learned something. Most of my latest tests have been about confirming parameters in my material model.

I would encourage those reading to go make stuff our of E/G and to enjoy doing it. I would also caution folks not to spill epoxy on themselves. I recently had an unpleasant skin reaction when a beaker of reactive dilutant splashed on my skin in the lab. It has taken a month for the rash to go away: Not Fun. Wear nitrile gloves, and be careful not to contact epoxy or hardeners!

Regards all,

Cameron

[RomanLini]

Beautiful work John!