DIY Tesla Impulse Turbine

[The Ignoble Troll]

Well, that's not good,... as I suspect the stainless shaft will always rise to at least 100° C.

The next test run will be interesting,...I replaced the melted spider with quick-set epoxy, essentially making a replacement spider using epoxy. If this too fails, I will use either a high temp epoxy or high temp silicone.

I wonder if high temp rtv gasket maker might work?

 

[Toymaker]

I wonder if high temp rtv gasket maker might work?

We're singing the same song ,... high temp rtv gasket maker is what I meant when I said, high temp silicone. Either the Red or the Copper should work, but both will likely require a filler material as they both dry very flexible. Unless a solid powder is blended in, the final spider may be too squishy soft.

I've found that all off-the-shelf quick-set epoxies remain slightly flexible after they fully set, a bit like hard rubber, which is close to the original spider material. Even though I don't know their temperature limits, due to their similar flex properties as the original spider, this is my first choice.

 

[Steamchick]

Having worked a bit with Silicon RTV makers.... 3Bond (JAPAN) make a gasketing material that "cured" all the oil leaks on Sumps and timing chests on ALL Japanese engines by all makers. Loctite (Europe) were going to make some for Nissan in the UK under licence from 3 Bond, but then 3 Bond opened a Belgian mixing plant to mix the stuff in Europe so that never happened. I tested some Loctite development stuff versus the 3-Bond material. It had a huge % of filler, compared to most other RTVs available. Gave it tremendous durability and resistance to "squeezing-out" from joints with vibration, thermal movement etc. between joint faces, however, often the aluminium or thin steel was nearly destroyed when dismantling. BUT when applied to engines lasting 150,000 miles, the OEM business preferred the longevity and durability of the joint compared to replacement costs if it was ever serviced... The filler made the finished material as hard as boot-heel rubber... So it you can buy some 3 Bond gasket stuff and make inserts you may have a relatively hard and durable elastomer insert.

BUT Silicon rubber is not normally a material for the application you have. Heavy cycling compressive loads. I strongly recommend you get some Polyurethane rubber and cut to size, shape for the inserts. This is among the most fatigue resistant material for this sort of application, and should withstand 100C, I think?
Search on-line for specs of material before you spend $s. Your project is costing a lot, so you don't want to waste $s, but apply sensible money where required. You may also find that tyre tread rubber is very fatigue resistant and can handle the temperature. To cut rubber with a razor-edged knife lubricate the blade with water, or soapy water. NOT petrol, etc. or grease! Big blocks of rubber may be cut from old tyres? (scrap Industrial tyres can be worn in the middle but have thread blocks on the edge that are big?). You can also cut hard rubber with a hacksaw - with water to lubricate the blade.
Glue rubber with "Rubber glue" as using superglue or similar works well initially, but has very poor durability against fatigue failure in this sort of cycling application.
K2

 

[Toymaker]

Having worked a bit with Silicon RTV makers.... 3Bond (JAPAN) make a gasketing material that "cured" all the oil leaks on Sumps and timing chests on ALL Japanese engines by all makers. Loctite (Europe) were going to make some for Nissan in the UK under licence from 3 Bond, but then 3 Bond opened a Belgian mixing plant to mix the stuff in Europe so that never happened. I tested some Loctite development stuff versus the 3-Bond material. It had a huge % of filler, compared to most other RTVs available. Gave it tremendous durability and resistance to "squeezing-out" from joints with vibration, thermal movement etc. between joint faces, however, often the aluminium or thin steel was nearly destroyed when dismantling. BUT when applied to engines lasting 150,000 miles, the OEM business preferred the longevity and durability of the joint compared to replacement costs if it was ever serviced... The filler made the finished material as hard as boot-heel rubber... So it you can buy some 3 Bond gasket stuff and make inserts you may have a relatively hard and durable elastomer insert.

BUT Silicon rubber is not normally a material for the application you have. Heavy cycling compressive loads. I strongly recommend you get some Polyurethane rubber and cut to size, shape for the inserts. This is among the most fatigue resistant material for this sort of application, and should withstand 100C, I think?
Search on-line for specs of material before you spend $s. Your project is costing a lot, so you don't want to waste $s, but apply sensible money where required. You may also find that tyre tread rubber is very fatigue resistant and can handle the temperature. To cut rubber with a razor-edged knife lubricate the blade with water, or soapy water. NOT petrol, etc. or grease! Big blocks of rubber may be cut from old tyres? (scrap Industrial tyres can be worn in the middle but have thread blocks on the edge that are big?). You can also cut hard rubber with a hacksaw - with water to lubricate the blade.
Glue rubber with "Rubber glue" as using superglue or similar works well initially, but has very poor durability against fatigue failure in this sort of cycling application.
K2

Thanks for all the detailed information Steamchick.

Besides the Red and Copper RTV I mentioned, I'm not sure what other gasket maker materials are available here in Thailand. 3Bond sells quite a few epoxies, RTV, Contact glues, etc here in Thailand,....I'll need to look for their gasket maker.

Whatever I do, I wont spend a large sum of money on a repair as a new plum coupler is only $4.00 including shipping.

 

[The Ignoble Troll]

Thanks for all the detailed information Steamchick.

Besides the Red and Copper RTV I mentioned, I'm not sure what other gasket maker materials are available here in Thailand. 3Bond sells quite a few epoxies, RTV, Contact glues, etc here in Thailand,....I'll need to look for their gasket maker.

Whatever I do, I wont spend a large sum of money on a repair as a new plum coupler is only $4.00 including shipping.

Is "the right stuff" by permatex available to you? I've seen that stuff hold up exceptionally well in uses like head gaskets for air compressors.

Possibly mixed with a fiber like fiber glass or carbon fiber, it would hold up?


An alternative would be to have one 3d printed from nylon, if you know someone with a printer.

Carving one out of uhdpe could be another root.

 

[The Ignoble Troll]

Having worked a bit with Silicon RTV makers.... 3Bond (JAPAN) make a gasketing material that "cured" all the oil leaks on Sumps and timing chests on ALL Japanese engines by all makers. Loctite (Europe) were going to make some for Nissan in the UK under licence from 3 Bond, but then 3 Bond opened a Belgian mixing plant to mix the stuff in Europe so that never happened. I tested some Loctite development stuff versus the 3-Bond material. It had a huge % of filler, compared to most other RTVs available. Gave it tremendous durability and resistance to "squeezing-out" from joints with vibration, thermal movement etc. between joint faces, however, often the aluminium or thin steel was nearly destroyed when dismantling. BUT when applied to engines lasting 150,000 miles, the OEM business preferred the longevity and durability of the joint compared to replacement costs if it was ever serviced... The filler made the finished material as hard as boot-heel rubber... So it you can buy some 3 Bond gasket stuff and make inserts you may have a relatively hard and durable elastomer insert.

BUT Silicon rubber is not normally a material for the application you have. Heavy cycling compressive loads. I strongly recommend you get some Polyurethane rubber and cut to size, shape for the inserts. This is among the most fatigue resistant material for this sort of application, and should withstand 100C, I think?
Search on-line for specs of material before you spend $s. Your project is costing a lot, so you don't want to waste $s, but apply sensible money where required. You may also find that tyre tread rubber is very fatigue resistant and can handle the temperature. To cut rubber with a razor-edged knife lubricate the blade with water, or soapy water. NOT petrol, etc. or grease! Big blocks of rubber may be cut from old tyres? (scrap Industrial tyres can be worn in the middle but have thread blocks on the edge that are big?). You can also cut hard rubber with a hacksaw - with water to lubricate the blade.
Glue rubber with "Rubber glue" as using superglue or similar works well initially, but has very poor durability against fatigue failure in this sort of cycling application.
K2

I think Polyurethane might creep a bit at those temperatures?