Diy turboshaft engine

[azwood]

Made this intake not sure i need it but looks good.

[azwood]

Cool got it thats the stuff i was after thanks

Oct 6, 2018 3:57:19 GMT -5 racket said:

It seems to work for me jetandturbineowners.proboards.com/thread/680/diy-turbines?page=1 just hit the pic icon

[azwood]

I've been working on an apu by co vetting my leaf blower to 12v it has a 5.5/1 increacey box should produce enough flow to get the job done

[azwood]

Trying to make start and cool from the driver's seat I've built a butterfly valve in the intake on a pneumatic ram and a feed for the blower fan so on startup the intake will automatically open.

[azwood]

And yeah that's a gate latch I up cycled on there lol just need a returned spring and finish welding her up.finger's crossed it all works

[azwood]

The car starter on my blower doesent seem happy to spin to full speed and its getting hot I cut to solinoid part off where the earth was and I just put it on on the outside housing not sure if this is causes my problem. It worked fine to start with could it be an alinement issue

[turboron]

azwood, I use a similar starting system on my smaller Garrett T3 based DIY gas turbine. I use a cast exhaust cutout with an offset flapper valve. The blower forces it to one side cutting off the regular air inlet during spool up. Once the DIY gas turbine is at idle compressor discharge pressure I turn off the blower and the DIY gas turbine sucks the flapper open. Works great and there is nothing in the flow path during operation. When I shut the DIY gas turbine down I turn on the blower. The flapper shuttles to the start position and I run the blower to cool the power turbine exit down to 300 degrees F or less.

Thanks, Ron

[azwood]

Oct 25, 2018 20:06:14 GMT -5 turboron said:

azwood, I use a similar starting system on my smaller Garrett T3 based DIY gas turbine. I use a cast exhaust cutout with an offset flapper valve. The blower forces it to one side cutting off the regular air inlet during spool up. Once the DIY gas turbine is at idle compressor discharge pressure I turn off the blower and the DIY gas turbine sucks the flapper open. Works great and there is nothing in the flow path during operation. When I shut the DIY gas turbine down I turn on the blower. The flapper shuttles to the start position and I run the blower to cool the power turbine exit down to 300 degrees F or less.

Thanks, Ron

Cool glad I should work

[azwood]

It should work lol.just hope a starter has enough power to push the 5.5/1 gearing to spool the blower wheel but I'm not afraid experiment (he who never made a mistake never made anything right)

[turboron]

azwood, I remember John use a modified leaf blower on his first units. He closed down the clearance somehow to increase the discharge pressure. My blower puts out around 5 psi as I recall.

Thanks, Ron

[turboron]

azwood, my blower is 5.77 psig and 3 Horsepower.

Thanks, Ron

[azwood]

I did think I could set the blower wheel close to the inner wall to up its flow glad that works it was 550fps with the petrol motor not sure of the HP but ill check the cc of the motor tonight

[racket]

Hi Ron

Yep , I made up a disc of alloy sheet and glued it to the impellor blades with silicone sealant to produce a shrouded impellor , then I used some sticky backed cloth bandage tape stuck to the plastic casing to remove the last bit of clearance , this then allowed the impellor to produce some "pressure" rather than just flow.

The alloy sheet is still in place more than 15 years latter , the blower gets plenty of use around the yard in between cooling down the engine runs.

Some of the leafblowers that also double as a vac have very generous clearances to prevent jamming of the impellor and really need their clearances reduced to be effective starters for our engines.

You must be really getting some rpm/tip speed into your blower to produce >5 psi of pressure , an ideal starter :-)

Cheers
John

[enginewhisperer]

yeah I was just doing some calculations this morning for a potential starter blower and with my 167mm impeller it will need about 21000rpm and 20hp to make ~5.5psi

What are the wheel and rpm specs on your blower Ron?

[azwood]

My blower toped out at 7500rpm