First, just as a test if I succeed

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 .

  fantastico lavoro sui cingoli caro Edwin , lavoretti da seguire con attenzione ... . saluti ... alla prossima up e buona domenica da robby62....   

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 .

Today I had again the time something to do here.

If I need now form a new centrifugal casting I can drain quickly with the Resin negative now.



In the right form now still missing, the vent holes. The I install with a 1mm drill at all relevant points.



Allow the air to escape during the casting and also the holes are not sealed by the pressure plate I milled with a cutting disc just still air channels through the holes.





Now I can soon try out the new form.

Today I finally tried my hand in rotational molding again .

First powdered forms .



Here you can see the difference as beautiful as the powder adhered to the silicone.



Place the brass tubes for the pin bearing into the mold.



And close the mold and screw it into the skid pan .



After I had melted enough zinc , I could pour it into the opening.



The first pour but has become anything yet. The speed was too high and not pressed the mold enough to each other. As a part of the zinc is ejected from the From and only two of the six members are useful . I think the temperature of the zinc was too hot .







So the same again and this . Sometimes with less temperature and lower speed This was but now back to low. The casting looks good, but the form is not completed and the parts so flawed .



That will probably still be some work until it works to my satisfaction.

After a few small changes it went today. I do but only piece by piece and so I first have installed a few vents .







It has gotten better , but I see the need again to make a new form and I also do not know if I need a slightly harder silicone for this, as some slightly bent chain links come from the mold. On the second cast I had way too little material which is why two of the forms were not filled sufficiently . What I do not like is the surface of the chain. That was much better from the single form.

So now I have at least some members whose quality is just sufficient for use according to my understanding . Therefore, I have now started with the assembly of which is still a lot of work .

First, disconnect the small brass tubes with a band saw , as far as you can reach it .



The pipe pieces that you can not cut so I have to cut out with a small blade.



Then I can edit the links with a small belt sander .



When connecting bolts I use 2mm spring steel. It is so stable that 150kg train at enem piece of chain had led to no deformation or tearing .



And here , the combined length of chain . The slightly shorter is still the tensile test , but it can recognize the much better surface. The temperature of the mold makes the way, since no difference.
In the foreground is a small piece of 1/16 chain as a comparison.

 Veramente geniale, sei molto bravo, ho visto anche il lavoro sul Famo, complimenti...  
  

Great job master!!!     

By the way I bring it to me, too just 3D CAD with and just created a caster in 3D for it to be able to create master.

It's times as one half of a roller in 1/6