Star rolling with rice grain cores

[taiwanluthiers]

I have used rice grain cores with good success. The key is find a less elongated rice grain whenever possible (that means do not use Thai rice because they're more elongated. Taiwanese rice is less long and there are even round rice out there). Lead core is said to be the best but since I live in a country that does not trust its citizens with guns, so no one sells lead shots except in bb gun calibers (Japanese pyros may also have this problem, anyone care to share what they use?)

 

I've found that starting with a large amount of material, and do not use too much water is a good idea. It is the easier to make 1000 rolled stars than 100, so if you are making 100-200, then cut them.

 

You'll be surprised how much comp is needed, you will want at least 500g of comps if you want about 500 1/4" stars, better to have extra than not enough.

 

When starting out the cores have a tendency to stick to each other, especially if too much water is used. Use a needle to break them up whenever necessary. As the stars grow you can use more and more water per spray and they will pick up comps more easily.

 

When making a large number of stars you may want to consider pre-rolling them since as the stars get bigger, your bowl may get too small for them.

 

I use a plastic "wok" (basically a foot basin used in the bathroom, Aluminum works better as it is round and doesn't have trenches inside for comps to work into)

 

Roll hard and fast, your hands will be tired.

 

When using rice grains, the star is actually not perfectly round but its still acceptable. As they get bigger they start becoming more and more round. I made probably about 300 3-4mm stars... I will need to make more comps because I am making 6mm stars.

Edited July 27, 2012 by taiwanluthiers

[Zumber]

I have used rice grain cores with good success. The key is find a less elongated rice grain whenever possible (that means do not use Thai rice because they're more elongated. Taiwanese rice is less long and there are even round rice out there). Lead core is said to be the best but since I live in a country that does not trust its citizens with guns, so no one sells lead shots except in bb gun calibers (Japanese pyros may also have this problem, anyone care to share what they use?)

 

I've found that starting with a large amount of material, and do not use too much water is a good idea. It is the easier to make 1000 rolled stars than 100, so if you are making 100-200, then cut them.

 

You'll be surprised how much comp is needed, you will want at least 500g of comps if you want about 500 1/4" stars, better to have extra than not enough.

 

When starting out the cores have a tendency to stick to each other, especially if too much water is used. Use a needle to break them up whenever necessary. As the stars grow you can use more and more water per spray and they will pick up comps more easily.

 

When making a large number of stars you may want to consider pre-rolling them since as the stars get bigger, your bowl may get too small for them.

 

I use a plastic "wok" (basically a foot basin used in the bathroom, Aluminum works better as it is round and doesn't have trenches inside for comps to work into)

 

Roll hard and fast, your hands will be tired.

 

When using rice grains, the star is actually not perfectly round but its still acceptable. As they get bigger they start becoming more and more round. I made probably about 300 3-4mm stars... I will need to make more comps because I am making 6mm stars.

nice work..!!

But still i dont convenienced with rice grains as a star core.

If you want perfect round star then you are supposed to use core which should be circular in shape.

You can use small balls used in ball bearing and easily get them from any automobile store.

[Seymour]

Actually, the primary reason I see that may hinder the use of rice as a core material, is the same that supposedly means you should not feed uncooked rice to birds... it can swell up and 'break things'

 

If you are careful you can use potentially swelling materials successfully, but if you roll too thick a layer or roll it too wet, cracked stars could reward you.

 

While round is obviously the best shape for cores, I can assure you that to get perfectly uniform and spherical stars you can use many different shapes. I have personal experience with long rice like stick shaped grains, cut stars, and mixed shape from granulating mixes that can best be described as 'gravel'. It is known for some Japanese shell builders to use cut cores in some complex colour changing stars, evidence of which on a youtube video of a factory visit, and Shimizu's description of Ammoiumn perchlorarate based strobes in FAST).

 

If you roll properly and avoid activities that hinder uniformity (rolling too wet or too dry or too fast, or too few stars) the cores are tamed by the rolling, and rather quickly they grow rounder and rounder. Admittedly some stars will wander from the conformity and do rebellious things like form conglomerates of stars, especially when very small. These stars should be removed periodically, and can usually still be grown in to good larger stars, or broken in to pieces that can.

 

Then all you need to do is periodically pass the whole lot though a selected screen, and the stars that go through get rolled more, and those that repain are put on a tray, where all things going well, they form nice layers and grid pattern rows.