Raptor Composite Aircraft

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FarmBoy

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Joined
Mar 14, 2012
Messages
129
Location
Gainesville, VA
"...when it reports 1800f the temps coming out of the cylinders are likely closer to 1350f."

The explanation does seem to be tainted with with optimism.
Exactly. "My airplane is 'likely' not going to explode." Not an approximation I would make without verification. It would have been just as easy, and prudent, to install at least one single cylinder sensor to verify the differential and more prudent to install 5 more to ensure early detection of an injector leak (of which probability of failure increases with accumulated hours - especially with JetA and operating temps on the high side)!
 

Scheny

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Joined
Feb 26, 2019
Messages
169
Location
Vienna, Austria
There was some confusion about the "locking pin".

The aileron and elevator are both driven by the same torque tube the sidestick is mounted to. It has an elongated hole milled into it, in which a screw is running through. For elevator motion, the torque tube is moved to front/rear and the screw slides within the hole. For aileron movement, the screw is translating the input to a coaxial "sleeve" where the push/pull tube to the aileron is mounted to.

Peter later noticed the hole dimensions widened by 0.2mm, resulting in play in the aileron. He then changed screw between metric and imperial (adding these 0.2mm), so it was not loose anymore. I am pretty sure this has nothing to do with the PASS.
 

pictsidhe

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Jul 15, 2014
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7,374
Location
North Carolina
Seriously asking.... do any of you allow such guesswork in design work?

I can't imagine it being difficult to determine, with certainty, the actual EGTs. Regardless, I would not risk machinery or lives knowing this blowtorch is a few feet from the occupant portion of this vehicle.
I don't. Hell, I've installed EGT sensors on beater cars. Drill and tap a hole. Not difficult. I would not risk an engine to save the 20 minutes it takes to install one while I had it apart any way.
 

TarDevil

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Joined
Jun 29, 2010
Messages
481
Location
Coastal North Carolina/USA
I don't. Hell, I've installed EGT sensors on beater cars. Drill and tap a hole. Not difficult. I would not risk an engine to save the 20 minutes it takes to install one while I had it apart any way.
It's as though he doesn't want to know. Just run it until it melts, then find another failure excuse for his adoring YT fans.

I've tried remaining unemotional about this project but Peter seems not to care about endangering lives. Hard not to feel some animosity.
 

pictsidhe

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Jul 15, 2014
Messages
7,374
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North Carolina
It's as though he doesn't want to know. Just run it until it melts, then find another failure excuse for his adoring YT fans.

I've tried remaining unemotional about this project but Peter seems not to care about endangering lives. Hard not to feel some animosity.
I too think he is avoiding issues. He's avoided doing any horsepower measurement. They'd confirn that his engine was well set up. Sustained high power runs, absent. Fuselage pressure testing, to less than he plans to pump into it.
Lots and lots of half jobs, often built on each other. When I build something as critical as ailerons, I test every component as I go. Not after people comment on them flapping during the first taxi run.
Peter likes to get everything together, then see what falls off. I do not think that is a sensible way to build something as safety critical as an aeroplane.

A thousand Scottys are looking at those EGTs and screaming "Cap'n, she's gonna blow!"
 

flyrite

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Joined
Mar 22, 2015
Messages
50
Location
lyons, ga. in the usa
Well DAM BOYZ ....Some of you Fellers better get right over there and stop this mad-man. I don’t know how anyone can sleep at night knowing how screwed we all are with the shenanigans this low life that has no sense or duty of care for his fellow humans!
PLEASE...PLEASE...Somebody save us!
 

AdrianS

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Joined
Jul 5, 2014
Messages
486
Location
Australia
<snip>
Peter likes to get everything together, then see what falls off. I do not think that is a sensible way to build something as safety critical as an aeroplane.
Isn't his background in software?
I've met plenty of people who program like that ;)
 

Andy_RR

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Joined
Sep 29, 2009
Messages
214
Location
Melbourne, Australia
"My sensor is at the Y pipe, not at the exit from the heads. Where the Y pipe converges cross sectional volume goes from 2 to about 1.5. That reduction in cross sectional area drives up the temperature at the sensor. So when it reports 1800f the temps coming out of the cylinders are likely closer to 1350f."

The explanation does seem to be tainted with with optimismignorance
Why would gas increase in temperature when it is expanding...?
 

FarmBoy

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Mar 14, 2012
Messages
129
Location
Gainesville, VA
Excessive backpressure could account for a small amount and, depending on the sensor response, the measurement of all 6 exhaust pulses could account for a slightly higher measured response but accounting for a 450F rise seems to be quite a stretch.

EDIT: That said, even with Cerakoted and wrapped headers, those pulses will still see a loss of temperature during transit from the head to that sensor (those pipes aren't glowing for no reason). While the sum of all gains and losses could still be positive, it can't be verified to not actually be negative without a sensor (or sensors) located close to head. I would be happy to pay Peter to install one just to satisfy my curiosity!
 
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Rik-

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Joined
Sep 13, 2019
Messages
348
Location
San Rafael, California
When is the next video due? He kinda hinted at a video of the front wheel lifting off the tarmac, dare we anticipate that all 3 wheels have lifted off in his testing?

Thoughts on the belt. On a supercharger setup one pulley can have a flange to keep the belt centered but if the shafts are parallel to one another you can have no flanges and the belt will stay centered. On a supercharger setup the belts are kinda loose when cold due to allowance for thermal expansion of the engine. I wonder if he has any allowance in the tightness for thermal expansion?
 

FarmBoy

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Joined
Mar 14, 2012
Messages
129
Location
Gainesville, VA
When is the next video due? He kinda hinted at a video of the front wheel lifting off the tarmac, dare we anticipate that all 3 wheels have lifted off in his testing?

Thoughts on the belt. On a supercharger setup one pulley can have a flange to keep the belt centered but if the shafts are parallel to one another you can have no flanges and the belt will stay centered. On a supercharger setup the belts are kinda loose when cold due to allowance for thermal expansion of the engine. I wonder if he has any allowance in the tightness for thermal expansion?
He added belt tensioners after early iterations. You can see these in past build videos.
 

pictsidhe

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Joined
Jul 15, 2014
Messages
7,374
Location
North Carolina
Excessive backpressure could account for a small amount and, depending on the sensor response, the measurement of all 6 exhaust pulses could account for a slightly higher measured response but accounting for a 450F rise seems to be quite a stretch.

EDIT: That said, even with Cerakoted and wrapped headers, those pulses will still see a loss of temperature during transit from the head to that sensor (those pipes aren't glowing for no reason). While the sum of all gains and losses could still be positive, it can't be verified to not actually be negative without a sensor (or sensors) located close to head. I would be happy to pay Peter to install one just to satisfy my curiosity!
Hell, I'd put one in for him. For the smug superior aspect! Then I'd measure the torque on the mains and calculate horsepower.
 

Scheny

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Joined
Feb 26, 2019
Messages
169
Location
Vienna, Austria
Don't laugh about the scales. I was consultant for system safety in electric cars. One of the biggest issues is to verify the torque.

There was one project with a van (I don't remember if it was a Mercedes or something else) where torque was verified by measuring force on the motor mount, so literally 3 little scales.
 
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