Battle Tanks Nederland

Now I've made a few casts with the form .











I am satisfied with the form, as it is not yet , mainly because of this it would be greatly weaken a fundamental error produced by a small offset to the joints and too much air is still there. But that is not bad because I get to die here first as a lesson to see the knowledge for the very expensive spin cast .

So I have begun today from this experience to build a new shape.

Back in the Lego box , because the simple and works well . So I am learning slowly better to model with clay which also makes getting to be fun .







For casting the mold I have found a better now suitable for silicone and so the Grundbassis is ready.



After the silicone is fixed you can have the difference between the old form and the new left , see right.



Also the division of the form I get a little modify the three fittings to better separate . Here, the modeling for the second portion .

The new shape is finished ..... and works much better .



Here you can already see that it fits better and more exactly to each other .







The small vent holes I made with a drill. With a very high rotating works quite well and I have exactly the right places .



And so I'll have the same cast and a new chain link.





After the resin was cured sufficiently the big moment came .





It still has bubbles , but this time it's useful with a little reworking.



On the next cast I'll try it with an injection, but one learns ....

Currently here is more of a learning effect for Resincasting in multipart forms of complex parts.

Although the surface is now reasonably well when I take the members out of shape, but sometimes only thinly over the bubbles collapse immediately when I edit the parts.
So continue in the trial.
Meanwhile I injeziere the resin heated to 40 ° C with a syringe in which to vent it before just fine. Simply compress the opening and pull the piston and already all the air collects at the top and the resin is almost clear.
I also heat the mold in my little annealing prior to about 40 ° C . so that the resin can be almost water thin pressed into the mold and leave bubbles almost like water. Nevertheless, I have always more or less air to different , changing places. Oh yes breather is already there.





Now I just try out with what I can best repair defects. Apoxie is currently best suited , mainly because it after curing has a similar hardness.



So I 'll probably have to build a third form with the experiences from the first two, but this completely interpret for the resin injection from below takes place in the form of a standing up so that the air is inherently displaced upward .

Hallo Edwin,

Ich bin sehr froh zu sehen wie Du die verschiedene Gußverfahren darstellst und sie beschreibst. Möchte das gerne auch mal ausprobieren. Kannst Du bitte die zum Giessen verwendete Materialien erwähnen?

Grüsse,

Erwin R. Robijn

Hallo Robijn,

das sillikon und die Harze findest Du hier gut und günstig. Nur beim resin kann es ohne Gewerbe Schwierigkeiten geben durch die Deutsche Gefahrstoffverordnung, Es dürfen bestimmte Produkten nicht mehr ohne weiteres an Privapersonen verkauft werden.

http://www.breddermann-kunstharze.de/" onclick="window.open(this.href);return false;

Das Sillikon hat die Bezeichnung Si6GB
Das Resin....R12GB



Resinform the Third ...

After I so do not get the bubble theme with the second form in the handle , I build from the experiences of the first two of a new form again . This I will only provided with a single vent and a filling .
But first, back to embed the link in plasticine. To get this even particularly smooth the putty beflamme I still very carefully with a small gas burner.



For mixing of silicone and Reesin I use a fine balance.



After the silicone is networked I cut the surface tension raised by the edges with scissors so that the mold can lie flat .
so it looks from form to form better.





I share the top again with modeling clay and paint the silicone release agent before casting with a . For this I use a simple oil for cooking . But there is not any oil used . But you can easily find out by the silicone smeared with a thin film of oil. If it pulls evenly and thinly over the surface , you can use the oil , if it looks like water on a fresh car polish it will not work .



So I 'll do it then with the third molding.



In my annealing , curing works much faster and better.



And so the new shape still looks as a block and then separated .





Now in the forms I make no vent in the casting sprue and more . These later I drill with a drill to the areas where they are needed.

Since I was approached because of the reuse of syringes.
I'll harden the resin is pull the plunger out and press the resin with a wire from the syringe. It is almost as often reusable.







Even the thought of minimum weight of the tank I'll probably have to move by 5 to 10kg for top . I have today once weighed a chain link zamak and finished at about 55g the pair of chains will probably come to about 10kg . For this, the chain through their high weight but should run well .

Hi Edwin,

Was mich zudem interessiert ist Sink(druck)guss. Ich habe verstanden, dass Panzerketten mit dem Sinkdruckgussverfahren erstelt werden. Machst Du auch so einen Versuch oder wird dass zu teuer/aufwendig?

Gruesse Erwin R. Robijn

Hi Erwin,

ich mache die Ketten dann im Zink- Schleuderguß.

Das ist natürlich aufwendig und man benötigt eine Schleudergußmaschine wie ich sie mir dafür schon gebaut habe, aber dafür sollte ich dann immer 9 Kettenglieder mit einem Mal gießen können. Zudem verwende ich zum Gießen Zamak. Diese Zinklegierung füllt bei weiten nicht so gut Formen wie Blei, oder Zinn. Auch deshalb der Schleuderguß. Dafür ist sie sehr hart und fest, was sie wieder notwendig für Ketten macht



Finally it works so that I can accept it .......

But first, how to proceed.
This time I have no sprue and vents built into the form , I would like to fill the mold in an injection .
Therefore, I now still need a filling and venting in the mold. This I am simply by i install in the appropriate places with the narrowest rivers jewels form a hole with a 3mm drill bit. With a sharp drill rotates very high it works wonderfully .



Add the powdered form I put back the 3mm brass rods, which I do I need as a placeholder in the form of the bearing tubes of the chain pins .
Here you can also recognizable that my forms from time to time also be better and more accurate.



And I can now press the preheated in the syringe and slowly vented resin into the mold. Here I swing the on-edge shape slightly so that there are no air bubbles can collect in corners.



I press the resin into the mold without stopping until no air bases with the resin from the mold exit .. The syringe daf while in no case be drawn from the injection port , otherwise you again inflated a bubble of air into the system.



After the resin was hard now see the link like this.
I still have a few bubbles , but only on the bearing surface of the chain link and I certainly still get away .



And so the raw plastered link then looks . The few bubbles I can now easily repaired with a spatula and then the link is now usable.

Moving ahead ..........

Although the Master of resin which I am doing now are not perfect and still need a little rework, but they are used and there will be more.
For the spin cast I need 9 pieces and when I have them together I can start with this form.

Again, it goes a little further.

The Resinmaster are now cleaned and the flaws I have been milled, which takes incredibly long.
So now I could touch up with 2K filler this.



Tomorrow they will then sanded

Thus , in small pieces precedes it .

I now have first made me a little form , so that I can recognize and assess problem areas better. Because an error costs only a fraction of the material and the time that is necessary in a spin cast .



The resulting casts are as I did not expect at wide error-free , but now I know where I must begin . It is also a good test whether the chain so fit and works as I imagine it . I once put a piece of 1/16 chain next to my chain links . The 4 members now weigh even as much as a small chain .







In addition, I have also tried the same , the strength of the chain , but at 1200 N train me the wooden backing of the links is broken without that I could impress the chain.

So now I have started to build the spin cast , which is very expensive .
I use to drive silicone, which is then crosslinked in the oven.

For cutting I use the pressure lids .





And so I work now the master link into the mold.



Since I now have a lot of work , partly because the shape is not as usual in two parts, is special consist of 8 parts because of the complicated shape of the chain links .

And it is again a little further.

The silicone, which I wanted to use for the Schleudergußformen so well and stand hard it is, I have gotten off of this form . It's too tough and takes too long to create the such a complicated shape. If it can not finish in a certain time, the silicone pulls back away from the part and you have to edit it again. For simpler forms but I will still use it again and here I can also use it for other and is not lost.

So I ordered plasticine and 2K Sillikon and I thought from my experience a new form despite the limbs form should be in two parts possible.

So today I lift first the pot evenly filled with modeling clay and smoothed.



The master I then distributed evenly in the second step .



And so I am now doing the links individually embedded in the clay , which is quite complicated in this case, but maybe I can pour tomorrow .

Today I finished the chain links embedded in the clay and smoothed the surface of this.



So I could shape also teeming with 750g HT Sillocon and bleed.



Now I have to wait until tomorrow and hope soon to be able to pour the second mold part.

Today, I now could separate the mold from the clay.



After I had the mold half cleaned from the remnants of clay, I could complete for the casting of the upper mold half.



And then again pour with HT silicone. It is not so easy to remove the trapped air in the silicone, but it geling me then.



After the mold was able to cure a few hours in one of my temper Chambers sees the shape after separation from so now.



It is not yet quite perfect succeeded, but one learns and now I have to deal with it again the vents drilling and higher temperature, but then I can try the first pour.

After I am not satisfied with the first spin cast . I have since made ​​a small mistake and removed the master to clean from the first mold half. It indeed does not believe as creep is the silicone and now I 'm just here to build a new one.

This time I let the master links in the form and make me remove the Knetmassereste so really quite complex work.



For this I use different screwdrivers , homemade spatula , a scalpel and a pipette.



It works best with the homemade spatulas , I had that in 1.2 mm spring steel remnants made ​​that I have burned out at the end , knocked flat with a hammer and fed ground .



And that amn gets like this the masters out yet .



For this I have discovered another well usable effect. The plasticine can be fine air bubbles in the resin , the master lock .

After I finished the casting of the upper part of the lower part of the form num.



Could I also this casting. The cap in the middle of the filling opening for the zinc.



After everything was nicely cured saw the moldings after separating from better.



But before I finished making the mold and still build with the vents , I'm still the master casts made ​​from resin . So I have the hassle with the shape is no longer relevant and the silicone can without much preliminary work direckt giesen on the master plates . The silicone mold will not even live forever.





The only drawback to this method is the rather large consumption of Resin, but it is still worthwhile if you need a new form .
Here you can see how pretty much the resin must be plate .



The same course I did that with the second mold half , only that I 've placed a displacement in the middle to save Resin .