[veteq]

I think its time to freeze this thread. No one on earth today will have time to read 334 pages & 4000 posts, but if one does he will earn a Doctorate . Its up to the cnczone moderators to decide. New baby threads on this area will be suitable i hope.

We need "Birth Control", (for new posts i mean....)
(wrong)

I would say, lets go for 5000.....

[cncagain]

Hey guys. I don't agree with the idea of freezing the thread. With all the work that so many people have done to get this far, it'd be a shame to stop just before we get a full process and answers. it took 4k posts to get just the amounts and ratios of filler worked out, we need to wait until the resin question is answered. It appears that is all that is left for us to have a tried and true method to make commercial quality polymer concrete machine bases. A definitive write up is still going to be required, but it is so close! We've worked out vibration, ratio and size and material for fillers, inserts, mold making, and along the way have had input from people who've made their own machines commercially. I can't speak for others, but I frequently check this thread to see how far we've come.
Every time I look at my little epoxy/granite sample and the diy/moglice sub rod and bearing I made, I think about this thread. My hopes are that this gets answered this year, but if not, the number of posts doesn't seem to bother me, and to require baby posts on this topic would effectively kill progress. Some linear fashion of referring back to this topic needs to be in place first. I think the order of these "post-children" would be difficult to keep track of, while this thread keeps everything in place and order so we don't start going backwards. How many times in the ages have we had to reinvent things because nobody thought to keep the progress made available and in a linear fashion.
My unasked for feeling on the topic of putting down this thread.
Ken

[vishnu]

Guys please don't take this the other way, we are not trying to close this thread. I would rather say this is the most extensive topic i have come across and i am pretty much a fan of this thread. We have almost come a long way from the start and we need some concrete mixes for people to try out. lets all put them in a linear manner so others will really understand what this thread really means with examples. I am eager to see our members building really nice machines with E/G so this thread will go further than its today. I am being practical.

[veteq]

Guys please don't take this the other way, I`m are not trying to close this thread. I would rather say this is the most extensive topic i have come across and i am pretty much a fan of this thread. We have almost come a long way from the start and we need some concrete mixes for people to try out. lets all put them in a linear manner so others will really understand what this thread really means with examples. I am eager to see our members building really nice machines with E/G so this thread will go further than its today. I am being practical.

In the index there is a link to a all practical builds etc. So this is already done.
In that thread there is the info about used mixtures, testsamples and machines,
have a look there.
This is the development log and all info that contributes to the "optimum" mixture,

We dont want it to be closed....

[johnohara]

vishnu:

Mix and post some pics. That's why I started the thread "Epoxy Granite in Practice."

Put on your goggles, throw on some gloves, mix it up, post some pics and start stressing about air entrainment and compressive strength.

I agree with you. There's been a lot of buzz over on Hoss's thread about the Grizzly G0704. Every time I see a pic of that beautiful machine I think about casting a base for it or at the very least filling it up with E/G.

~John

[jhudler]

vishnu:

Mix and post some pics. That's why I started the thread "Epoxy Granite in Practice."
~John

This thread was started as a what-if... it still is, I think it should remain as the thread where we Experiment with diferent formulas of EG.

John, your thread is about practice, taking what we've learned from this thread and and applying it in other threads.

That being said:
Perhaps it time to request our own seperate Forum (e.g., Polymer Composites or just simply Epoxy Granite).
It would allow use to maintain our group and prevent it from being scattered to other Forums and this fragment our efforts.

-Jhudler

[brunog]

Perhaps it time to request our own seperate Forum (e.g., Polymer Composites or just simply Epoxy Granite).
It would allow use to maintain our group and prevent it from being scattered to other Forums and this fragment our efforts.

-Jhudler

I like the idea of a separate forum

Best regards

Bruno

[veteq]

A seperate forum would be cool, but then this thread has to be moved over there...???
And there i could start my build thread in time...

[ckelloug]

I think this thread should stay as well since it gives a critical mass of people to keep discussing and it sucks in new people.

I'm still accept help from any volunteers who want to work on the index as it only covers the first 1200 or so posts.

I've written some special software that builds the cross reference list and makes the actual posting so all one really has to do is make a list of post numbers and one line summaries and I can format it for my indexer compiler to rebuild the index linked to the appropriate posts.

I've never had any takers for this but all it really requires is summarizing posts and the software takes care of the rest.

PM me if anyone wants to volunteer for index duty.

I intend to get over to the lab this weekend and work on getting the new vibration table up and running.

--Cameron

[vishnu]

I stay by you guys. A piece of info http://www.americanmachinist.com/304...se/80845/Issue

[Brenck]

I think its a good idea to have a thread with other subthreads about EG on cnczone.

Lets say topic called E/G and inside of it sub forums of lets say:

EG formulars ( discuss all formulas etc.. )
EG experiments tryouts etc.. ( Discuss practical experimentation )
EG machine base samples and castings ( pictures and etc... )
EG damping and vibration ( discuss everything about vibration when it comes to EG )
EG mold construction ( discuss issues and idea about molds to cast EG )

and so on...

With about 7 to 10 sub threads we can separate things on a really specific way and make it way better to research and discuss.

This is my idea and opinion only. Hope it will help

[jhudler]

CNCzone.com-The Largest Machinist Community on the net! > Other Machines > Epoxy Granite

http://www.cnczone.com/forums/forumdisplay.php?f=481

I/We asked and it was granted... however.

I was hoping Epoxy Granite would be placed off the root instead of under 'Other Machines'. But then, I wasn't specific... I just assumed.

Perhaps CNCAdmin will move it up to the root.

-Jack

[AFAIK]

30% Agsco #6 Al2O3 [ 3.360 mm ]
10% Agsco #4 quartz [ 1.680 mm - 0.590 mm ] ( 94% --> 1.680mm - 0.840mm )
27% Agsco #2 quartz [ 0.590 mm - 0.177 mm ] ( 89% --> 0.500mm - 0.250mm )
09% Agsco #2/0 quartz [ 0.149 mm - 0.044 mm ] ( 78% --> 0.125mm - 0.088mm )
16% 3M G800 Zeeospheres [ 0.200 mm - 0.100 mm ] ( 95% --> 0.200mm or smaller )
08% 3M G200 Zeeospheres [ 0.012 mm - 0.010 mm ] ( 95% --> 0.012mm or smaller )

I am trying to find all the materials in the formula posted by ckelloug using the conversion done by johnohara. I think I have (kinda) sourced the quartz in all 3 ranges of size:

http://www.permagard.co.uk/index.php...roducts_id=114

http://www.specialistaggregates.com/...se-p-1241.html

http://www.specialistaggregates.com/...ne-p-1238.html

These don't come in the exact size that the formula wants, nor do I suspect they will be the same size as is specified. I plan to buy some meshes and sieve them, although I don't know how much it would cost for the sizes I want.
I have tried to source the aluminum oxide, I haven't found any in the required size. I haven't done much research other than a quick search in Google for Zeeospheres, does anyone have a source for them? (and a rough price?)

I have designed the machine and am in the process of making the bottom mould using Contiboard. I hope to start a project log in the E/G forum once I have got the materials.

[greybeard]

AFAIK, sent PM
John

[ckelloug]

AFAIK,

Do you have something for the largest size range that I had specified as #6 aluminum oxide? In general, the theoretically optimal mixture varies if size components are missing. This slightly larger size helps get the packing density up.

Since you already have graded material, it may not make sense to sieve it. The formula I posted was based on the grading curves posted by Agsco for their stock materials. If I had designed around carefully sieved material I think I could have done a bit better at least theoretically but it would probably more expensive.

Best of luck.

--Cameron

[TZE]

Hi all!
A am sorry about my bad English but a have a great interest about E/G.
I respect all users here, but some time i can use only Soviet (GOST) names for materials(with live URL and/or appropriate data), because i do not know how they are exactly named in Europe and USA.
I live in Ukraine (ex-USSR country, located in Western Europe).
Something like real precision machine beds and parts made of E/G by Swiss technology were provided in middle of 80-s in Lipetsk (Lipetsky stankozavod, Russia, East region). It was a great machine-building plant(produced precision CNC milling, grinding machines, lathes, machine centers, master machines and so on). Many machines with E/G parts were built. But now all is dead...
I made some experiments with epoxy resin (so called EDP glue: EPOXY-520 -91% per mass, dibuthylftalate - 1% per mass and polyethylenepolyamine(PEPA) - 8% per mass ) mixed with artifical stone( 150grams of EDP were mixed with 1.5kg of stone, 200 grams of pure epoxy(with PEPA!) was filled on the top of the mix to provide an flat layer(6-7mm thickness) ).
I killed air with torch and meniscus was in 6-8mm from edge of casting.
Final results were funny(epoxy was not hot - only warm, pure epoxy is pretty well scraped with hardened scraper (58-63HRC) ) but my first E/G casting was sick due to sickness of wery "artifical stone" (my casting crushed at only 40 kgf per square cm). My piece of E/G cracked by stone (i see halves of stone in crack region), not by epoxy...

But that is my main problem:
We have lack of materials like table-top epoxy, nano-particles and Zeospheres here (I well know about e-bay, know about international shipping but there is a real problem with 100 or 300 grams for experiments).
Shakers, vibro tables, vacuum and thermocameras(PID regulate) are not a problem at all.

We have only Epoxy 525(ED-22), Epoxy 520(ED-20), Еpoxy 411(ED-16), DBF, PEPA here priced 4.5-5 USD per 1 kg. Also we have silica(0.1-0.3mm; 0,5-1mm) and different gravel. I also have metal chips and aluminium/bronze/molybdenium disulphide powder.

Can I do rather good castings (80-120MPa per stress and 80MPa per tension) and flat surfaces(0.02mm per 500mm) with that epoxy/filler or I must stop my experinents and watch for Dow Chemicals and other high grade matherials?

With regards, Paul .
P.S.: A am sorry about my bad English. I think & do much better than I post English ...

[AFAIK]

ckelloug,

I have not found the aluminum oxide in the size I need yet. Could more quartz be used or some other material instead of the aluminum oxide? I have found another site that has quartz in size ranges of 1-2, 2-3, 3-4 and 5-8 (mm) http://shop.touchstonefloors.co.uk/p...roducts_id=160

Thanks to greybeard I now have the option to sieve the materials if I wish, but from a rough estimate of the castings, I would be sieving about 400kgs so would prefer not to do it.

[greybeard]

.....Thanks to greybeard I now have the option to sieve the materials if I wish, but from a rough estimate of the castings, I would be sieving about 400kgs so would prefer not to do it.

I think the way to go is to sieve a sample of each of your supplies, say three samples of 500gms, work out a rough "size profile" for each, then work out what adjustment you need to make to get the overall profile you need.
Sounds easy till you get to the last step
Regards
John

[romandian]

hi, wasnt there a section on actual projects somewhere? or was that on another forum?

roman

[ckelloug]

AFAIK,

No need to use aluminum oxide for the largest fraction. This was used in my reference design because it is something that Walter, the thread's founder had easily available. It might in principle confer a small strength increase over quartz but it's the size that's most important and the largest size is one of the most critical parameters.

If you ask your supplier of aggregates, they may have grading curves available in which case you won't have to sieve anything to determine what's there.

If you can get grading curves, I'll model the mixture and see what the optimizer suggests for a recipe. 3-4 mm quartz should be fine in place of the number 6 aluminum oxide.

The zeeosphere distributor for Europe is in holland see the following:
http://www.zeeospheres.com/distributors.html

It's also possible omya cenospheres would work but they are hollow and this will lower the mass of your parts. Best of luck.

Regards all,

Cameron