Yeah Rubber is King. But how and where to get it the hard thing. If have any info I would appreciate.
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Cough cough raptor 2 hubs cough cough cough 
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Are we talking real rubber? Because that stuff has to be vulcanized. I would be a surprise if he did that.
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Dont know, only thing i know he used rubber of some kind.
I saw you found @visnu777 thread. Maybe he has an idea what material is the right to start with.
I used PMC-780 (http://smooth-on.com/), @hummieee used the stuff from bjb https://bjbenterprises.com/index.php/polyurethanes/castable/flexible/all-purpose/tc-680-a-b/ which he states is superior (and he did way more research) I was happy with my results though
btw, don’t forget to read the original thread on builders https://www.electric-skateboard.builders/t/diy-wheel-casting/6546
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The reason i chose PMC is because, a i saw @visnu777 thread in the original forum and Kaupo was so good to send me some samples and i can buy it over work. I am printing the molds for my 2 missing wheels, this time they are closed off at the top and i will put them in a selfmade vacuum chamber. Still even though i just poured that stuff into the mold without any degassing ect and i am still happy with the result. After the second batch is done, i will put them into the oven and put them on my board for spinn.
But i will say, in the future i will make a Silicone mold for repeat usage. It is more work, but it just pays once you have a good mold.
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How do you manufacture the molds?
Oh I see you 3D print them
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you can 3d print the whole mold, or 3d print the wheel and make a mold or 2 part mold if needed using silicone.
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I wonder if spinning the molds while/right after pouring would result in more balanced and round wheels when they come out the mold. Tough inside a vacuum chamber.
You do a final finishing step on a lathe?
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nice mold pic! the only downside Ive seen to using common room temp pour pu seems to be its rebound. you wont notice much if not pushing but its kinda like china clone stuff in that way. and smells. its really pretty durable though.
ive managed to get at least 1000 bucks worth of hot pour stuff and other stuff consumers don’t get access to. they wont sell it to you unless youre a biz. but being a biz is pretty easy to make happen or across fields works. and if you get the ears of the staff engineers that these big places employee especially you can get “samples” that are gallons. not saying will happen but seems the case across a lot of industry. was nice to find out. I may be dying early from doing hot pour pu at home.
@City-Blade-101 did that biz fold? with so much marketing and that video and guinness record and seem gone.
ive got two gallons of super high rebound 35 duro insole like stuff wasting away here. stuff deteriorates over time and cant think of what to do with it. boobs would be perfect.
id do a bigger reservoir for pouring into and don’t really need much on other side. sit it on its side. I guess you still have to polish and wax the inside and mold release? never done a printed mold and seems worth it to do it silicone.
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Got any stuff with good rebound?
I was thinking of trying the 70a duro from bjb.
Ill buy
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just the boob stuff. Was going to use it to Compress batteries but figured too soft.
I’ve never seen wheels as soft as 70.
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As a filler for casting everything into an enclosure it’d probably work fine
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Do you think it will work or 70a is too soft for a 125mm wheel, and should use 80a instead? Gonna use the bjb stuff. Thought since the cold pour stuff would kinda turn out like chinese clone wheels, would be ok to use 70a
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Hah nice! Made me think to pour my own Gummies since I have the design now 
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Never tried 70 and assumed too soft but if u have a mold and can pour another easy enough sounds good. Curious how it goes
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I just sprayed release agent on it, but i still had to destroy the mold. It was just too tight fitting, but my second wheelset will made of silicone molds. Still need to put my wheels in the oven for post curing. Keep you posted here.
BTW these are 70a wheels, but since they are so beefy it does almost feel like my fake flywheels.
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im far from an wheel expert but I’m surprised more people arn’t taking in contact patch, wheel size and urethane depth in consideration when they are talking about wheel hardness. to my simple mind that must make a massive difference.
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sorry , but i dont know if i understand exactly what you are telling above.
You got gallons of soft pu you used before which is now dead material to you bc you switched over to another material? Or did you give just advice its not easy to get the right material?
I tagged you because of the rubber wheels bc as a rain wheel option not as a generel urethane sleeve or wheel option.