Finished project - Hawk 650 tank isolators

Just a big of a brag.
The front and rear tank isolators on my hawk 650 were trash, and new fronts are unavailable. Took me about 2 months on and off to figure out a process to make these parts. Went so far as to look at machining the molds and building an injection molding machine, but a few nights of reading about how hard it is to do complex injection molded parts made me abandon going full Top Gear for that method.
It was a neat learning experience, and now I know what to do if I ever need to make another molded part again.

 

Really cool.

Any chance you could expound on the process you did use?

 

Those look to be very well done, please do share the process.

 

3D printed mold and 2 part silicone?

 

Nice job.

Not sure if that's how he did them, but I've made lots of pieces that way. It's incredible the stuff you can do with this technology these days.

 

Nicely done. It's always very satisfying to make something from scratch and learn a new process doing it.

 

Cool DIY project.

I wonder if 3D printing in TPU would work. It seems pretty rubbery on the YouTube.

 

Yeah. Printed molds and 2 part silicon. If you're going to use PU resin, you either have to seal the mold or use a special filament. Learned that in the experimentation. Now trying to see how I can get some fluro-silicone material in quantities other than 50 lb buckets.

Figuring out the mold design was 80% of the work. Then the best filament material. Then the injection system.

I've seen someone try printing the part in TPU. It doesn't come in a low enough shore rating (65A for my parts vs 80A, but felt higher), and it doesn't print as nice as molding the part. It's just too complicated with too many gaps and overhangs.

 

I have printed a bunch of stuff with "tpu like materials" some are very impressive, some others tear pretty easily.

 

There is a fairly active Hawk group on Facebook. You may find some folks in need of your parts over there.

 

Molding/pouring is quicker and yields a solid homogeneous part. Printing solid is slooooow, and doesn't always yield a useable part. What's neat about it though is being able to print a part at different densitys/infill at different places so as to allow certain flex and rigidity in specific areas. Printing is neat, but not always the best way. Printing molds and pouring however is pretty cool.

 

Nice work.
I worked for a urethane casting company awhile back. We did open casting of urethane as opposed to injection. Open casting will get you better performance than injection. That and an excellent urethane formulation is why the drive cushions I developed and sold lasted for years compared to the original Marchesini parts lasting a few days.
If you can design the mold to work for open casting then you can easily get a urethane from McMaster Carr that will perform well.

 

On the Hawk GT forum. Sent my sample parts out to another known member to have a second check, then doing a 'group buy' production run.

With the front mold, there's a bunch of locations for air to get trapped, so I have to have a bunch of vents and force the material in there. Rear isn't bad for open, but it takes forever to let the material settle, and then let the trapped air bubble out, add more material, rinse repeat. PU is less viscous than silicone, so it pours and flows easier, but then I have to take more time getting a good seal on my mold. And I have to use an expensive material for PU vs silicone that's harder to print consistently.

 

It's definitely a balance of tweaking the part design and the mold design so they work together to make the pouring easy and bubble free.

 

This is great stuff. I have been looking into something similar for some parts that TPU doesn't seem suited for. If only I had the time lol. Good work.

 

“If the women don't find you handsome, they should at least find you handy.”