moonpool
Member
Joined: June 2013
Posts: 28 
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Post by moonpool on Sept 23, 2020 0:06:38 GMT -5
Hello Turbine community,
This weekend I'am going to pickup a Solar T62-32 turbine engine. Can anybody help me to get some documentation. Any form of documentation is OK... Is anyone familiar with the (mil spec) type of electrical connectors, I need a few female plugs for the engine.
Thanks in advance
kind regards Rob
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turbotom
Junior Member
Joined: June 2011
Posts: 58
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Post by turbotom on Sept 23, 2020 19:42:56 GMT -5
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moonpool
Member
Joined: June 2013
Posts: 28
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Post by moonpool on Sept 23, 2020 23:47:49 GMT -5
Thank you very much for the link and connector information
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Nov 14, 2020 7:00:04 GMT -5
It's been a while, I'll offer any help. I believe I have all the documentation for this one. I know I have a drop in ECU. Just ask. Remind me in a week about the docs if I dont get back in a few days I will be out. youtu.be/TMOkb79D0V0Steve |
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Nov 14, 2020 7:10:55 GMT -5
Again it's been a while on this one for me, anyone figure out a way to prevent the throttle shaft from snapping? Seemed to be an issue 10 years ago. I believe I have some docs on that as well. Quick fixes from somebody putting it on a UL helicopter but they wouldnt fly it. Drilling out the shaft and pressing a pin in there or something.
Steve
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turbotom
Junior Member
Joined: June 2011
Posts: 58
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Post by turbotom on Nov 18, 2020 18:18:22 GMT -5
Again it's been a while on this one for me, anyone figure out a way to prevent the throttle shaft from snapping? Seemed to be an issue 10 years ago. I believe I have some docs on that as well. Quick fixes from somebody putting it on a UL helicopter but they wouldnt fly it. Drilling out the shaft and pressing a pin in there or something. Steve Easy solution: Handle it carefully! If you ding it or try to unscrew the joints without countering the torque, it snaps. It's basic knowledge among the folks that operate these engines since a long time that the throttle valve shaft is fragile, so just be careful. Make sure the torque motor is supplied not above the maximum current as specified by the manufacturer (0.5A) and your shaft won't get damaged by it. If you use a GAC governor that's capable of >2A without any additional limiting, you will snap the shaft and fry / demagnetize your torque motor. The manuals are available since more than a decade, and they are very clear about that, so everyone can get the required information. If the shaft snaps, the repair is possible though not that simple as you have put it. But basically it's ginding the remaining shaft flat, precision drilling the through-hardened material approx. 10mm deep (3mm or 1/8" TC drill), machining a new top end piece (preferably from high-strength stainless) to tightly fit the drilled bore while leaving the required gap for the o-ring seal, bonding in the newly machined top end (loctite 648), and finally machining the notch for the lever clamping screw with the correct angle vs. the valve orifice. I've repaired several and calibrated many of such FCUs and they are being operated on experimental helicopters without any problems. Regarding your clip and the comment to permit anyone who likes to stand next to the engine and operate it: Sorry, this is plainly irresponsible. These engines do fail, and they do fail catastrophically. Just a few days ago such an incident happened, and as we analyzed it, it started with the oil injection assembly that is positioned around the sun gear to come lose, getting in between the intermeshing gears. This caused the sun gear to shed all of its teeths, effectively taking all load off the power head. Since the ring gear / drive shaft assembly, together with the externally driven machinery's inertia, kept the accessories rotating for a few seconds, the fuel flow to the power head didn't get interrupted. The power head spooled up to probably round about 160% for maybe three seconds until the turbine wheel exploded. At that amount of overspeed, the shrapnels aren't contained. If there are bystanders around at the "wrong" spot, they will get serieously injured or killed. Do yourself a favor and run your engine in remote places. Keep spectators at safe distance and absolutely out of the plane of rotation. |
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stevie
Junior Member
Joined: November 2020
Posts: 55
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Post by stevie on Dec 10, 2020 7:31:27 GMT -5
What ECU are you using, or are you manually controlling it? Again, I've designed the ECU to aggressively keep the engine from running. If something runs away, in any way, it is off in a few milliseconds. Alas, anyone can miss something. This ran fine for years, data logging so I could see any changes over time. Things can change suddenly though. The PID fuel servo snapped it I suppose or? Cross referenced the oil to straight up 10W-40 and red diesel fuel. For years and hundreds of hours.
In your condition did you see a quick cool or rise in in EGT? Oil pressure drop? I can see that if the RPM drops on the sensor(s) the turbine runs free it whacks wide open on the fuel. What are you using this engine for? What is attached to? Feedback from other sensors? How did this fitting come loose?
In the video of course you can see no one is in the danger zone. It's nice to give someone a chance and perhaps inspire them. For another thread eh.
I suppose I have the same info on the shaft as you have and it is fragile, in the generators it ran for the life of the engine? Any input is nice, if I see it or anyone else does in the future.
I was using it to drive a 24V alternator. Always joked it was like hitting a thumbtack with a sledgehammer. Did charge the batteries.
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turbotom
Junior Member
Joined: June 2011
Posts: 58
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Post by turbotom on Dec 11, 2020 21:29:25 GMT -5
What ECU are you using, or are you manually controlling it? Again, I've designed the ECU to aggressively keep the engine from running. If something runs away, in any way, it is off in a few milliseconds. Alas, anyone can miss something. This ran fine for years, data logging so I could see any changes over time. Things can change suddenly though. The PID fuel servo snapped it I suppose or? Cross referenced the oil to straight up 10W-40 and red diesel fuel. For years and hundreds of hours. In your condition did you see a quick cool or rise in in EGT? Oil pressure drop? I can see that if the RPM drops on the sensor(s) the turbine runs free it whacks wide open on the fuel. What are you using this engine for? What is attached to? Feedback from other sensors? How did this fitting come loose? In the video of course you can see no one is in the danger zone. It's nice to give someone a chance and perhaps inspire them. For another thread eh. I suppose I have the same info on the shaft as you have and it is fragile, in the generators it ran for the life of the engine? Any input is nice, if I see it or anyone else does in the future. I was using it to drive a 24V alternator. Always joked it was like hitting a thumbtack with a sledgehammer. Did charge the batteries. The engine was used in an experimental aircraft. For several reasons, I will not go further into detail on the application. The engine was operated with a purposely designed ECU with data logging and condition monitoring, that has proven its reliability in more than fourty installations. There was no prior indication of pending problems. The incident happened at approx. 65% torque / 100% rpm (so round about 100hp supplied at the shaft). The exact sequence of the failure is still under investigation but it must have been caused by hard objects from inside the engine gearbox becoming dislodged and being flung around between the gears, finally resulting in all the teeths of the sun gear being sheared/ground off. This must have happened within approx. 3...4 seconds. At the very moment that the sun gear lost all its teeths, the power head was effectively running off load, and since the RPM is being measured at the ring gear, which gradually spooled down, the ECU "attempted" to keep drive shaft speed constant by further increasing fuel flow. Since the power head was spinning free, all the 100+ hp were available to accelerate it. At probably round about 150...160% rpm, the turbine wheel was no longer able to withstand the centrifugal force and just burst in three major pieces at the undercut area at the hub rear face. Those fragments were too energetic to stay contained inside the engine housing. The inertia of the gearbox and attached components provided more than enough energy to keep the fuel control unit (fuel pump in particular) spinning fast enough to supply fuel to the power head until it self-destructed. There wasn't any other mecanical problem present with the engine, the ECU, FCU and lubrication system were running flawlessly as the logs prove. These kinds of failures can happen, and in case of this particular engine type with the standard sensors installed, there's no way this outcome could have been prevented. If a CDP ratio sensor or a proper high speed turbine shaft rpm pickup had been installed, there may have been a tiny chance to avoid this catastrophic failure. But it's questionable if the fuel system would have been able to react fast enough. I will not go into any more detail nor publish photos of the remains of the egnine at that time. I may only add that fortunately noone was injured as the result of this mishaps. |
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