Resin prints are usually much stronger than FDM prints since the layers are chemically bonded. The resin I use is very strong.
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Yep, I know they are not the same. How do you think it compares to injection molded parts? I would guess the nylon ones are much stronger.
I’m interested in getting some custom 30T pulleys printed for a project actually.
They are very similar to injection molded. I could do a 30t set for $38
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Im interested, but im in Canada.
I can pay half whatever shipping cost is
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I needed a custom bolt/hole pattern as well. I haven’t finalized the model quite yet but I will soon and let you know!
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The thing is, this still doesn’t even compare to the GF reinforced Nylon, PA6/GF30 which I would assume the nice plastic pulleys are made of.
@Printedprecision I really appreciate your effort and I wish you best of luck with this. Resin prints ARE indeed much stronger than FDM, we know this because of the aforementioned reasons. However, I agree with some others when they mention the testing. My FDM pullies didn’t even start to show tooth wear (ABS) until about 100 miles in. After that, they wore quickly and some of the teeth broke. While I don’t think the resin will wear quite the same or have the breaking issues, I would heed the advice and get some more quality testing in here.
I personally use 3D printed pullies in combination with 2 inch 10-24 screws, and the combo works great. Don’t have to worry about broken plastic pieces in the wheel, and haven’t had any skipping issues due to flex.
We have resources here on the forum and I’m sure some people would be able to get you a lot of miles on them, especially if you offered a special price to several who offer to test them for you. It’s an option to keep in mind.
I believe that with successful testing you can have a market here, but otherwise, people here generally don’t accept untested (basically) parts at face value.
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Send them out to testers and build the rep. Charge at cost to the first few to get some miles on them. That’s what most do.
Biggest thing that hurts a pulley for me is picking up stones and I fear how the pulley will fair with one of them
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I’ve been testing several solutions to the aforementioned chipping issue. While the pulleys do not chip easily even with rocks being thrown at them during use, the still do chip slightly. The first thing I tried was to cure the prints much more slowly than normal. This allows more time for the resin to settle and bond to the other layers. I now do this regularly.
The other method I am looking into is using a blend of the tough resin I regularly use and a flexible resin. By using a mixture of resins the parts maintain their strength while becoming much less brittle. I still need more research into this method but it could lead somewhere.
As far as testing these pulleys out, I do have a plan. I’ll be sending these pulleys out for a small profit compared to the production cost. My plan is to honor a refund system, so that anyone who has their pulley break can have it replaced or refunded at no cost to them. This way I still have the opportunity to expand my operations while simultaneously guaranteeing a risk free purchase.
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Alright so just for a quick price check, what would you be thinking for 2x 40t x 12mm pullies for kegel wheels, with the ability to screw into them? For example, this is the model that I use to print FDM.
I could sell a set of 40t pulleys for $35-40 dollars and I can pay half of whatever shipping costs. I would have to check the amount of resin that print would require (hence the $35-40) before I could say how much I would definitely sell those for. I believe it would cost me about $7 in resin per pulley and about 18 hours in printing total plus another 2 hours of post processing.
Interesting, alright. Good to know
As far as testing goes, I’m sending a pair of 38t kegels to @longhairedboyfor him to try out and I’m giving another one to a friend of mine whose board I helped build.
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@mmaner @BillGordon and @anorak234 should all get sets as well. These three will give you a honest review. They are also well respected in the community.
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@BillGordon and I have discussed sending him a test set. Not sure where we’re at on that front but @longhairedboy ‘s pulleys are next in line to be printed.
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Thanks for the @.
I would be happy to put some abec style pulleys through the paces of there’s the possibility.
Definitely agreed that Bill and Mike are the experts here when it comes to testing. Damon is probably just as good too.
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@anorak234 I’ve messaged everyone mentioned by @J0ker except you about trial runs on these pulleys. The amount of pulleys I’m printing right now will take a few days since I need to make at least three sets.
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40$ for a pair of pulleys is past aluminium price though. Its good for really rare pulleys like venom mach 1 or speed vent but kegel especially its like $15 for an aluminium press fit
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ROFL. Prolly just a good, you kill me 
.
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There are loads of test with resin vs FDM printed parts if you google around. The issue with printed pulleys is not that they break but rather the tooth wares down. I would assume however that a FDM printed Nylon would last longer, because of its toughness and slippery nature. Blue is stronger but also way more brittle than nylon. I have used printed pulleys for the past 2.5 years or so. The ones I’m currently using has about 700-800 km on them. And are still more than usable. Will probably use them for another 300-400 km before I swap them out. And that will be because of the rapid belt ware.
And like anything there are loads of factors when it comes to how long pulleys will last. Belt width, Tooth count, belt tension, the amount of dust, sand gravel and crap you roll over and get in to the drive. And most importantly how aggressive you ride. I’m on a street setup, riding mostly on roads doing 50-60 km/h most of the time to keep up with traffic.
Resin might however be interesting to use with specialty cores like seismic and venom. Where the an FDM printed pulley would break because of its weaker layer adhesion. Resin might also break idk but it will definitely have a better chance at holding up as long as you don’t hit the pulley on too many curbs.
Oh btw I have a spool of polymaker CoPa sitting took the leap from 910. So my next set will be using that instead. Il let you know in a few months how many miles I’m getting out them.
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