Nessalco Posted November 28, 2015 Posted November 28, 2015 I am going to be making a set of star sorting screens over the next few days. I've noticed that most of the commercial screens available have a resolution of 1/16". Is that adequate, or is it worth the trouble to make a set with 1/32" resolution? So far it seems that the 1/16" resolution makes for a rather ragged break when it burns out - but that may be just my imagination. Kevin
Maserface Posted November 28, 2015 Posted November 28, 2015 If it were me, and I was trying to emulate the Japanese, I would go for 1/32" or maybe even tighter. If you are going through the effort you might as well take it to the highest level, IMO
Col Posted November 28, 2015 Posted November 28, 2015 I would opt for a star sorting machine to save space and cost. You`d need nine screens for 1/4" to 1/2" in 1/32" steps
ddewees Posted November 28, 2015 Posted November 28, 2015 Hunter had a set sized in single millimeters. Not sure if that's smaller or larger though.
Mumbles Posted November 29, 2015 Posted November 29, 2015 How small of increment do you think we could use, and still be able to sort the stars while wet? If you try to sort wet stars with a metal mesh screen, the square holes will eventually shave slightly oversized stars allowing them through. While round holes have more contact with the star, and thus more reinforcement, I'd imagine there's still a minimum amount oversize to get caught. I'm just kind of thinking out loud here, as this might affect the smallest useful increment. IE, there's no use in having 1/64" sorters, if they're only effectively accurate to 1/32" I've heard Mike Swisher state that the best of the best Japanese exhibition shells have stars accurate to 0.1mm. To be honest, I'm not sure if he meant that they sort them to that sort of precision, or if they're capable of yielding that sort of precision via their methods. Sizing is most important when dealing with cores and smaller stars. Bigger stars grow more uniformly. Maybe a set of very accurate screens between 1/4" and 3/8" would suffice, and then use a coarser graduation for larger sizes just for final sizing would be most appropriate.
MrB Posted November 29, 2015 Posted November 29, 2015 Slightly offset rollers, and a small downwards slope, with catch baskets below creates a sorter where you can cherry pick any size, but if you need to run the stars through twice. Once to get rid of the "to large" and once to get rid of the "two small" ones. Of course, you can have multiple catch baskets, but the distance between 19,20, and 21mm catch baskets isn't going to be that far, (Unless you go with really long rollers, creating other issues) if you want to work with fractions of mm, you pretty much have to go with a over / under, and at least 2 passes, and take a few sample / dummies for a testrun to dial it in. Not quite a "screen" but a screening process, if one want to call it that... It's also slower then just screening the stars.B!
Col Posted November 29, 2015 Posted November 29, 2015 Set the roller and plate parallel, adjust the plate with M5 fine threads (0.5mm per full turn). Multiple passes wouldnt be an issue if you`re looking for perfection . If you make sure the batch doesnt contain any undersized stars, only the correct size can fall through, any that are too large will drop into the container at the far end of the rod. Using precision ground shafting and engineering quality straight edges will provide close tolerances.
MrB Posted November 29, 2015 Posted November 29, 2015 I prefer using 2 rollers, rather then a straight edge, leaves me with no stationary edge that can cause... wear, on the stars. (shaved flatspots, and so on.) But it's the same idea, and pretty much the same build.B!
Nessalco Posted November 29, 2015 Author Posted November 29, 2015 Thanks for all the input. I had seen the roller idea but had forgotten about it. Kevin
Mumbles Posted November 29, 2015 Posted November 29, 2015 Have any of you guys ever tried to drill out your own bucket bottoms to make star sorting screens?
Nessalco Posted November 29, 2015 Author Posted November 29, 2015 Have any of you guys ever tried to drill out your own bucket bottoms to make star sorting screens? I have. I made a set of not-bad screen from the larger Skylighter plastic chemical containers. I used a drill press and step-drill with 1/32" increments. Worked OK, but not efficient and not really big enough for my purposes. Right now I'm considering drilling lexan plates with the same step-drill and mounting them in frames. I can't imagine drilling something like a 5-gallon bucket by hand. Hundreds of holes for a 1/4" screen. Kevin
Mumbles Posted November 29, 2015 Posted November 29, 2015 I agree, drilling all of those holes sounds awful. I've come across this video a few times though, and it looks to work pretty well. It's hard to say how long it took, but he's drilling holes just over 3/8" Mainly I was curious as to how accurate the holes were. I remember building one of those poor man's star plates off passfire that is made from two pieces of polyethylene cutting board melted together. After I drilled all 180 holes I discovered that most of the holes had shrunk just a tad, and everything was undersized. I had to go back and redrill everything, got it all out of alignment in the process. It was basically useless, but I was too mad about the entire afternoon I wasted to throw it away. https://www.youtube.com/watch?v=spHlrv6KH8Q
OldMarine Posted November 30, 2015 Posted November 30, 2015 Why wouldn't perf plate such as this work for sizing?http://www.mcmaster.com/#perforated-steel/=1010fss Please Dear Lord tell me I'm not gonna need to build every damned piece of this hobby ;-)
Mumbles Posted November 30, 2015 Posted November 30, 2015 I had forgotten about those. They work great, but there isn't a very good selection of sizes once you get larger than 3/8" openings or so. Actually, I bet using these for the small sizes, and drilling out/buying the bigger ones is probably the best of both worlds.
dusty56 Posted November 30, 2015 Posted November 30, 2015 Passfire has info to print star screens that increase in 1/32" increments. Of course you must have access to a 3D printer. I have drilled some buckets to use and it is a pain but it was cheaper than buying a printer. One problem with drilling is that quite often a small burr remains and that impacts the size. There are special bits with cutters at the rim of the bit to reduce this problem They are costly (relative) and not all sizes are available.
MrB Posted November 30, 2015 Posted November 30, 2015 Should be easy enough to go over all the holes, on both sides, with a oversized drillbit, a sharp one, and just touch up the edges by hand.Just as boring, or worse, then drilling them in the first place. Not to sure id want to do it in front of the telly either. Plastic scrap everywhere... B!
Col Posted November 30, 2015 Posted November 30, 2015 For size accuracy and perfectly round holes, its best to drill slightly undersize and run a straight reamer through afterwards.
mikeee Posted November 30, 2015 Posted November 30, 2015 The steel plates will rust over time, you would want stainless steel if possible or brass or copper.
OldMarine Posted November 30, 2015 Posted November 30, 2015 (edited) The steel plates will rust over time, you would want stainless steel if possible or brass or copper.Whew! Went searching for perforated stainless in multiple opening sizes.I think I'd better hone my bucket drilling technique before I graduate to star rolling/sizing. They are mighty proud of their hole-y metal! Edited November 30, 2015 by OldMarine
starxplor Posted November 30, 2015 Posted November 30, 2015 There are always these:http://bucketscreen.com/ Screens build into the plastic of the top of a 5-gallon bucket, which fits conviently inside another bucket for screening. Screens are nestable like normal buckets are, so you can separate multiple sizes. [Disclaimer: I know this guy as he is local to me, but I have never bought or used one of these bucket screens]
OldMarine Posted November 30, 2015 Posted November 30, 2015 @starxplor Star sizing screens need round openings to avoid shaving the rolled stars apparently. I do like the bucket screens though. I got me some to work with until I can frame the set of screens I ordered from McMaster. I may order some more of the bucket screens because they are damned handy.
mikeee Posted November 30, 2015 Posted November 30, 2015 The steel plates will rust over time, you would want stainless steel if possible or brass or copper.I forgot to list aluminum as another option, cheaper then SS, brass and copper.Aluminum might tend to oxidize from chemical reactions though.The plastic bucket bottoms are cheap, easy to clean and won't rust.Kind of hard to find a better solution then the bucket bottoms.
calebkessinger Posted November 30, 2015 Posted November 30, 2015 No substitution for perfection.http://ctpyro.com/resources/sorter+15$25.jpgYeah, they seem to cost a fortune.. you won't ever remember that while you are using it.. Just wonder why you didn't buy one sooner. http://ctpyro.com/5.html I'm not much for bragging up other peoples stuff, but these are GREAT
OldMarine Posted November 30, 2015 Posted November 30, 2015 No substitution for perfection.http://ctpyro.com/resources/sorter+15$25.jpgYeah, they seem to cost a fortune.. you won't ever remember that while you are using it.. Just wonder why you didn't buy one sooner. http://ctpyro.com/5.html I'm not much for bragging up other peoples stuff, but these are GREATThose are much less expensive than the stainless ones I was looking at. Ding Ding...we have a winner!
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