TOPIC:

Jonny wrote:

silvertriple wrote:

... The Big Bear tires are badword exepnsive...



 

The badword rule #2 autocensor at its finest - keeping TamiyaBase safe in case Ned Flanders comes along & sees the short form of H-E-double-hockeysticks  


 

My bad, i got tricked again... 160+ euro for one single tyre (no taxes, no shipment) is really really really expensive...

Among my research I started to talk with someone on another forums about moulding tires. From the discussion, I'm now convinced it is possible to do with a single part for the center mould. The flexibility of the tire should be enough to get the center part out.
I'll need to work out the mould for one of the tires to try. I may even try with FDM printed mould first.

For DYI, Vytaflex 40 (soft) and Vytaflex 60 (medium/hard) might be the right target products for the tires compound. The products are not that expensive, pot time about 1 hour cure time about 16hours.
Needs to work this out

Thanks marc to work on this project. 

Yesterday, i met the people of Loisirs Creation RC (www.facebook.co...1397927717). They are a very small french company, and they put on the market vintage 1/8 buggy tires for 50mm wheels last year. They are doing things with a real passion, and they are really nice people, and I spent the day with them to discuss my ideas and learn about making tires (you can find their products on ebay : loisirscreations2009).

The discussion confirmed some of the things I had in mind: I need to rework my moulds to get this done with urethane resin... And from the discussion I learned some tricks about how the real mould is done and how the the tires are done with a injection press. I won't have access to this, but from both this and the discussion on another forum with NickCNC that should help me to do something...

Loisir creation are very efficient.  I modified my usa1nitro crusher in ep version with their spares

Printer is back online, and tests can resume... I reset all cura parameters to default and set a temp tower to reconfirm the temperature... Which is exactly what was set before. The retraction is now different and bubbles no more ( maybe the issue was coming from this.

Today's printing test has two objectives: confirm lettering would work. I'm printing this test in 0.2mm per layer. There should be a way to do better than this... And it should work.


Next objective is to make sure spikes can print properly as there is bridges and no support, and this will be the difficulty.

The first row of spikes seems perfect, even on the bridged part...


on the second row the overhangs are harder... A few degree of angle can change a lot. That being said: I've not done a single cooling optimisation yet on the printer and all is set to default. I have in mind he fact I want to change the extruder by a direct drive extruder and improve the cooling... But for the first test, it is not really bad.

I will print the full mould over the week-end. This is good progress and also good insights for the Big Bear mould which should be much easier to print than this one...

Since I started the experimentation with the Flex resin printed tires, I have a big question remaining in my mind... Would it be possible to print a Big Bear tire this way...

I've opened chitubox, put the tire in (not much ways to change the orientation), added supports and looked at it:


It appears my printer's bed is way too small for this... I'll have to try the molding way...

The first product issued from this CAD thread is born...





Files are available here :
www.printables....-bear-tire

Happy printing !