[walter]

http://www.knauer.de/index.php?id=114&L=2

http://www.epucret.de/en/products-so...ew/cast-parts/

http://www.rampf-gruppe.de/fileadmin...s_final_GB.pdf

[jhudler]

Nice find Walter!

Wow 0.25mm displacement at 10-30 Hz. The frequency is exactly in the range of what I've been using to mix the E/G.

I've seen this phasing of vibrating elements used before, it's very flexible.
They don't tell the whole story about what you can do with four vibrating elements, two on each side. They only show both sides in phase however, you can have one side 180 out of phase with the other and vibrate the mix in a circular fashion. The modes available are limitless, but only a few are really necessary.

I've been saving a couple of HUGE stepper for just such a task! But I never had the parameters until NOW! Damn another puzzle project piece falls into place.

Would like to know who make the Vibrating Elements. Though you don't really need to buy anything to make an eccentric weight on a shaft between pillow blocks.

Thanks Walter!
Jack

[greybeard]

Nice ones Walter.
I'm intrigued by the SCC's ability to be thixotropic and release bubbles of air at the same time without vibration.
That would be a useful property to have in the e/g recipe, and while I've come across the mention of super-plasticisers in several of the references, I don't know if an analogous mechanism is available to us with epoxies. I'll have to go back and do some more reading, but I suspect the answer is no.
What I have come across in reading about the concrete developments are good descriptions of the pros and cons of restricting the size range of aggregate sizes, and explanations of how more dense packing is achieved by an appropriate choice of sizes.

I'm even tempted to consider casting the x-axis components in a de Larrard recipe concrete, if I go back from my current design which uses rollers, rather than a travelling gantry.

John

[walter]

John,

Nice to see your project taking shape. Like many others, I'm watching with much interest.
:cheers:

[harryn]

Self-compacting concrete (SCC) is a relatively new product that sees the addition of superplasticiser and a stabiliser to the concrete mix to significantly increase the ease and rate of flow. By its very nature, SCC does not require vibration. It achieves compaction into every part of the mould or formwork simply by means of its own weight without any segregation of the coarse aggregate.


http://www.precast.org/publications/...1_Fall_SCC.htm

http://www.jstage.jst.go.jp/article/...1/1_5/_article
_

Gee, I wonder how similar this is to the work Thomas Edison (you know, the guy that lived 100 years ago) did on making special concrete for his concrete house project.

http://www.americanheritage.com/arti...996_3_50.shtml

He solved many of the same problems with aggregate segregation, long horizontal pours, vertical rises, etc. with careful control of the aggregate sizing and addition of bentonite clay to make the material "gel".

His concrete factory was known for producing concrete which formed exceptionally smooth surfaces and was stronger than anyone else's concrete of the time. Imagine what he could have done back then if he had epoxy ?

[greybeard]

Fascinating reading Harry. I wonder if his patents give any details of the recipe ?

Regards
John
Edit
Patent Number 1219272
Crushed stone, quartz or similar 1/4" - 1/2" 5 parts
"Ordinary sand" 3 parts
Portland cement 1 part
"Fine clay" (bentonite according to other link) 20% of cement used
"Water to make pourable slurry"

It would be interesting to discover if there were any other sources of info on the lab work that he did in developing his recipe, and how it compares to the recent work on high strength cements.
It seems there are still some houses standing that were made by his method in about 1917 at "Ingersol Terrace" (see harryn's link) so they've done pretty well strengthwise.

[Zumba]

http://www.knauer.de/index.php?id=114&L=2

http://www.epucret.de/en/products-so...ew/cast-parts/

http://www.rampf-gruppe.de/fileadmin...s_final_GB.pdf

Those crazy Germans sure like to play in the sand.

Here's one closer to home.
http://www.cptllc.us/samplecastings.asp

[ckelloug]

Wow Walter and John,

These are some quite incredible bits of info. As soon as I'm done playing plumber at my new building, I'll look more into them.

Cool linkies from Harryn and Zumba too!

Blah. Back to the salt mines. . .

--Cameron

[greybeard]

Well, I've finally started.
http://www.cnczone.com/forums/showth...028#post387028

A bit wordy to start with, but hopefully it will soon contain more drawings and self explanatory photos.
I'll also post here any general interest photos that may appear along the way.
John

[speed33317]

I've been looking at the German CNC site that has
been referred here in the past, HOLY SMOKES! those guys
don't fool around.

[ame]http://www.youtube.com/watch?v=LdleAxxA8u0[/ame]

http://www.thomas-zietz.de/

this is a homemade gantry mill with EG parts, looks pro-made.

also one has doubled the size of the lathe "revolver"

Wish I could read German , something goes wrong signing in
through a translator and won't allow it.

[jhudler]

Wish I could read German , something goes wrong signing in
through a translator and won't allow it.

Right mouse on the page and get properties. Copy and paste the URL into GOOGLE's translator.

Or click here:

http://translate.google.com/translat...hl=en&ie=UTF-8

[speed33317]

thanks, Yea that one works, its trying to go into a forum
that has to be signed into, somewhere the security gets
messed up with the password, i'll just have to learn German :-)

this is the one I would like to translate..
http://5128.rapidforum.com/

Peters CNC Corner - "Peters CNC Ecke"

[lgalla]

hi Guys,
I stated from the beginning of this thread that the Germans were a head of us on E/G casting.These guys even have servo motor races!Hopefully they learned a lot from Walter and Cameron and the numerous posters on the thread.I have attached a picture from the opening thread of the German technology.Is it the tape measure or the smooth casting that is the secret ingredient we are missing?I don't know.Any ideas?

[speed33317]

Yea, have you seen how big some the machines are that they are building?

Some guy is building a huge lathe with some sort of milling
quill attached.

There are so many posts on that website and the fact I can't
read German , I probably won't be able to find it again.

[walter]

I've been looking at the German CNC site that has been referred here in the past, HOLY SMOKES! those guys don't fool around.

I think Thomas Z. posted here before. His second machine (FS2MG) looks especially good. I'm a big fan.

[ckelloug]

Walter's right. Thomas did and said he'd be delighted to answer questions although he said English is not his first language. PM him. Also, rotarySMP seems to know about a lot about this and he speaks both English and German fluently.

Regards all,

Cameron

[Zumba]

Nice link, speed.

Here's the link to his CNC mill page.
http://www.ktm-reiseenduro.de/tz/fs1mg1.htm

Looks like he spray painted his casting.

[peach mcclure]

what is an 80/20 frame?

[RotarySMP]

The German guys really don't have any magic. Their mineral mix was nothing special. They didn't give the inpression they worried too much about zeosoheres and perfect packing ratios. The didn't vaccum evacuate the air bubbles, I thing they just vibrated it.

Their magic was "getting started" They "just did it".

I really liked how they used a cnc router to cut 2D shapes out of plastic sheet, which they stacked to make the base mould shape. http://www.ktm-reiseenduro.de/tz/images/mg/bild6.jpg

They kept things pretty simply, building in parts, moulding in drain lines and steel strips to be machined for rail interfaces after cure. Then assembled the parts.

Nice work. Those Italian Elte HF spindles are pretty tasty (and very affordable).

[thomasz]

Hello all an a good new year!

It seems I should a few words speak here about our work with mineral casting. ;-)
Mark is right - first we made attempts with different component densities of the mineral.
Today we buy finished mixture (google silimix). Our own mixtures were too time-consuming for us for a continuous quality - in addition, worked very well.

Our small FS1MG was only the first prototype. Now we are busy with the building of the form for the new FS2MG. The litte video you port ist from the little prototyp.

The really important is correct compression of the casting mass. Forget vacuum, forget glass fibers and other aggregates. Mix a good raw material after the curve of fuller (0,4) or buys a finished mixed material. Give 10% resin and hardener to it and fill the form.

And now watched out: with vertical oscillations around 70 Hertz for the correct compression during you fill the form. Depending upon mixture, form and condition the frequency can deviate also somewhat. As for this an external vibrating machine with a frequency changer provided and to our vibration table attached.The external vibrating machine sits on a pendulum, so that only vertical oscillations will transfer. A simple physical principle.We use a Epoxy resin and hardener with long pot life (600 minutes). So we have enough time to fill the form's.


The bottle and the tape in the other picture in your posts are only to the size comparison. ;-) And yes - we drink beer. ;-)

Bye
Thomas

P.S. Thanks a lot for your many ordering my Demo-CD!