PST J600R shutting down? What could cause this?
#27
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Hopefully this solves the problem. Ran the pump today for 10 mins and its strong. Then I noticed when I was fueling there was a very small leak. So probably air getting into system. One of the main nipples for the main tank was loose. took it apart cleaned it well and put it back on with white tape and then did a leak check and no leaks, put silicone around the nipple. gonna wait for it to dry a few hours before I attempt another start. Fingers crossed this was the problem..
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Johnny,
Glad you found the leak and possible source of air bubbles during run ups. You don't really want to use silicone as a sealant since the kero/Jet-A attacks it. A better sealant is "Seal All" a automotive product that is resistant to kero and gasoline. It is available in most auto supply stores and comes in a tube like toothpaste.
Rgds,
Art ARRO
Glad you found the leak and possible source of air bubbles during run ups. You don't really want to use silicone as a sealant since the kero/Jet-A attacks it. A better sealant is "Seal All" a automotive product that is resistant to kero and gasoline. It is available in most auto supply stores and comes in a tube like toothpaste.
Rgds,
Art ARRO
#29
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Johnny,
Sorry I got called away and couldn't finish my previous post. You can leave the silicone in place for a short while as it takes some time for the fuel to attack it. Replacing it with "Seal All" will solve the problem long term. Since few responded to your problem I would contact Carlos Villereal (guessed spelling of last name) in Miami. He may attend the AMPS rally and you could contact him there. Carlos has wide experience with model gas turbines and should be able to get your PST running AOK. He has serviced both my RAM and FTE turbines and they both run just fine afterwards. Good luck and let us know how it all turns out.
Rgds,
Art ARRO
Sorry I got called away and couldn't finish my previous post. You can leave the silicone in place for a short while as it takes some time for the fuel to attack it. Replacing it with "Seal All" will solve the problem long term. Since few responded to your problem I would contact Carlos Villereal (guessed spelling of last name) in Miami. He may attend the AMPS rally and you could contact him there. Carlos has wide experience with model gas turbines and should be able to get your PST running AOK. He has serviced both my RAM and FTE turbines and they both run just fine afterwards. Good luck and let us know how it all turns out.
Rgds,
Art ARRO
#30
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Yeah I've sent Carlos an email and he hasn't responded yet. Gonna see if this solves the problem if not I will give him a call. Thanks for the tip on the silicone. Tanks mounted already so gonna leave it as is for now and when I tear it down again for mx I will change to the silicone you recommended. It was a pain in the butt to get that tank out. So fingers crossed no leaks and it holds up for a while
#31
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OK guys I think we are getting closer. Turbine started no problem of tx now and started up first time each time. EGT seemed a little high on idle so I backed out the egt probe a lttle and it brought the temp down. When I run idle to full throttle it ran great and I did it a few times. Although when I jam the throttle full turbine quits and I get the shut down data from high EGT temp. I raised the Ramp up Low from 10 to 12 and the Ramp up Mid from 6 to 10. If I use the throttle slowly its works great everytime from idle to full. But if I jam the throttle up it quits everytime. here are a few pics of the GDT at idle, full throttle.
Also noticed when I use a blower to cool the turbine the compressor does not spin. checked the starter and it is working and not engaged when I used the blower.
Also noticed when I use a blower to cool the turbine the compressor does not spin. checked the starter and it is working and not engaged when I used the blower.
#32
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Spoke to Carlos and he gave me some advice on what to look for but it involves taking the turbine apart which I'm not inclined to do. And he didn't want to touch the turbine. So back to dealing with PST in Thailand. If it's gonna cost me an arm and a leg to fix this rather just upgrade to a Bee or Jetsmunt VT 80
#33
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Johnny,
Thanks for the update and slowing the acceleration delay seems to help your situation. However, it is still not passing a slam test on throttle response. One thing to do is to slow the throttle response by using the "servo slow" function of your transmnitter or simply not slam the throttle. Note that I drove a turbine into a runaway fuel pump situation by a throttle slam resulting in a massive fire. I won't due that again! Glad Carlos was able to assist but note that he doesn't want to to get out of his comfort zone on turbine servicing. Too many bad outcomes. Either the Bee or VT 80 will be fine and you can count on local service, either JC or DreamWorks.
Rgds,
Art ARRO
Thanks for the update and slowing the acceleration delay seems to help your situation. However, it is still not passing a slam test on throttle response. One thing to do is to slow the throttle response by using the "servo slow" function of your transmnitter or simply not slam the throttle. Note that I drove a turbine into a runaway fuel pump situation by a throttle slam resulting in a massive fire. I won't due that again! Glad Carlos was able to assist but note that he doesn't want to to get out of his comfort zone on turbine servicing. Too many bad outcomes. Either the Bee or VT 80 will be fine and you can count on local service, either JC or DreamWorks.
Rgds,
Art ARRO
#34
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does anyone have their RAMP values at sea level they can post here so I can have a base point for adjusting. Spoke to gentleman I bought it from and he told me he had his setup for a 7000 ft elevation and never had any issues with it. Now he did say he had not run the turbine in over 3 years since he sold it to me which was last year. He had it for about 6 months and when he bought it he had sent it to PST for an overhaul and new bearings. So I'm leaning towards settings here and maybe a bad EGT if someone has one of those laying around they are not using let me know.
Last edited by Johnny9390; 06-15-2016 at 04:43 AM.
#37
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Got the PST600R working flawlessly now!! Changed a few ramp values to basically default, few minor changes but shes purring good not. No flame outs, jammed throttle forward many times and she responded as she should.. Ran great!! Got the batteries charging and heading to the field tomorrow for the maiden. "if it doesnt rain.." Will try and bring someone along to film the either seamless flight or dooms day lol. but I am ready to get this bird in the air..
My Values were
UP LOW 16
UP DOWN 8
MID UP 7
MID DOWN 4
HIGH UP 4
HIGH DOWN 4
GLOW DRIVER 190
START RAMP 70. My increase that a bit
My Values were
UP LOW 16
UP DOWN 8
MID UP 7
MID DOWN 4
HIGH UP 4
HIGH DOWN 4
GLOW DRIVER 190
START RAMP 70. My increase that a bit
#38
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Question No where in the manual tells you exactly what these values due. From my understanding the higher the number the slower ramp and vice versa correct? is there somewhere that explains in detail what these values do and when changing them should I go one step at a time
But hey Im just a dumb pilot.. if it works I am ok with that.. but would like to know a little more about how it works....
And PST does respond although it takes them about 4-5 days to respond an email. Thank got they are not on mars. can you imagine they send a message and you receive it but cant understand so you say "huh " wait another week for a response..
But hey Im just a dumb pilot.. if it works I am ok with that.. but would like to know a little more about how it works....
And PST does respond although it takes them about 4-5 days to respond an email. Thank got they are not on mars. can you imagine they send a message and you receive it but cant understand so you say "huh " wait another week for a response..
#39
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Johnny,
Glad you got your PST purring now. The ramp values determine the acceleration and deceleration of the turbine within limits of RPM and EGT. You would have to get a TEMS manual or one of their expert users to further explain these values and their effect. I would record these values in a logbook noting the ambient temp and humidity, ie, density altitude for further adjustments if required. If you operate the turbine in fairly constant conditions there should be no changes. Here in the northeast we experience ambient temps from 40F to 95F along with various humidity levels. I also fly in near sea level altitudes to low mountains- 2K'. etc. Some of my turbines fare well and others I have to put up with low power and slow acceleration or change parameters to adjust. A logbook helps to make these decisions.
Good luck on the maiden and let us know how it all goes.
Rgds,
Art ARRO
Glad you got your PST purring now. The ramp values determine the acceleration and deceleration of the turbine within limits of RPM and EGT. You would have to get a TEMS manual or one of their expert users to further explain these values and their effect. I would record these values in a logbook noting the ambient temp and humidity, ie, density altitude for further adjustments if required. If you operate the turbine in fairly constant conditions there should be no changes. Here in the northeast we experience ambient temps from 40F to 95F along with various humidity levels. I also fly in near sea level altitudes to low mountains- 2K'. etc. Some of my turbines fare well and others I have to put up with low power and slow acceleration or change parameters to adjust. A logbook helps to make these decisions.
Good luck on the maiden and let us know how it all goes.
Rgds,
Art ARRO
#40
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The simple explanation of what these values do is as follows... There are 2 'ramp switch' settings, where it changes from one ramp value to another. I think its in % of RPM range. Those settings are hidden unless you have a 'wide open' terminal. I have an old terminal from when I was a service rep for PST, but those ramp switch settings won't need adjusting anyway.
So, Ramp up low... Assume at this ramp setting of 16 per above - that it will take ~16 seconds for it to spin up from idle to full if it stayed at that ramp setting all the way up. However, it roughly accelerates at this rate until it hits the 'Ramp LowtoMid switch', at which time it changes acceleration rates the 'Ramp up mid' of 7 (think of that rate like like ~7 seconds if going from low to high if staying at one ramp setting through the whole range). It continues accelerating through the RPM range until it hits the 'Ramp MidtoHigh switch', where it changes to the Ramp up high setting (4).
If that is too confusing, think of it like this, assuming the following settings from above:
UP LOW 16
UP DOWN 8
MID UP 7
MID DOWN 4
HIGH UP 4
HIGH DOWN 4
Time to go from idle to full = [(LowtoMid ramp %) * (16)] + [(MidtoHigh ramp % - LowtoMid ramp %) * (7)] + [(100 - MidtoHigh ramp %) * (4)]
For example, if the ramp switches were placed at 33.333%, 66.666% marks, the equation would look like:
Time to accelerate from idle to full = (.333 * 16) + (.333 * 7) + (.333 * 4) = 5.3 + 2.3 + 1.3 = 8.9 seconds from idle to full.
Start ramp, kinda the same story. Take that number to very roughly mean the number of seconds to start the turbine.
Glow Driver of 190 = 1.9 volts to the plug, pretty simple. I use to run at 1.7. If it needs to go higher, check for oxidation on your glow plug clip.
If your turbine has trouble accelerating without blowing fire, it has a fuel atomization issue. That could be a combination of a turbine issue and / or be altitude related The common fix was to increase the Ramp UP LOW and Ramp UP MID settings. Ramp down, you are probably safe to leave them at the lowest possible settings unless you get some weird behavior in deceleration.
I would not recommend trying to solve it with a transmitter servo slow function. That is linear, whereas the equation above (roughly) simulates a parabolic curve.
In light of the above, I would highly recommend you somehow get your hands on a FADEC ECU and get rid of the TEMS. the Fadec is a far superior turbine controller and the 600R will have similar base settings to a ~15lb MW-54 turbine from many years back.
Good luck...
Kelly
So, Ramp up low... Assume at this ramp setting of 16 per above - that it will take ~16 seconds for it to spin up from idle to full if it stayed at that ramp setting all the way up. However, it roughly accelerates at this rate until it hits the 'Ramp LowtoMid switch', at which time it changes acceleration rates the 'Ramp up mid' of 7 (think of that rate like like ~7 seconds if going from low to high if staying at one ramp setting through the whole range). It continues accelerating through the RPM range until it hits the 'Ramp MidtoHigh switch', where it changes to the Ramp up high setting (4).
If that is too confusing, think of it like this, assuming the following settings from above:
UP LOW 16
UP DOWN 8
MID UP 7
MID DOWN 4
HIGH UP 4
HIGH DOWN 4
Time to go from idle to full = [(LowtoMid ramp %) * (16)] + [(MidtoHigh ramp % - LowtoMid ramp %) * (7)] + [(100 - MidtoHigh ramp %) * (4)]
For example, if the ramp switches were placed at 33.333%, 66.666% marks, the equation would look like:
Time to accelerate from idle to full = (.333 * 16) + (.333 * 7) + (.333 * 4) = 5.3 + 2.3 + 1.3 = 8.9 seconds from idle to full.
Start ramp, kinda the same story. Take that number to very roughly mean the number of seconds to start the turbine.
Glow Driver of 190 = 1.9 volts to the plug, pretty simple. I use to run at 1.7. If it needs to go higher, check for oxidation on your glow plug clip.
If your turbine has trouble accelerating without blowing fire, it has a fuel atomization issue. That could be a combination of a turbine issue and / or be altitude related The common fix was to increase the Ramp UP LOW and Ramp UP MID settings. Ramp down, you are probably safe to leave them at the lowest possible settings unless you get some weird behavior in deceleration.
I would not recommend trying to solve it with a transmitter servo slow function. That is linear, whereas the equation above (roughly) simulates a parabolic curve.
In light of the above, I would highly recommend you somehow get your hands on a FADEC ECU and get rid of the TEMS. the Fadec is a far superior turbine controller and the 600R will have similar base settings to a ~15lb MW-54 turbine from many years back.
Good luck...
Kelly
Last edited by Kelly W; 06-27-2016 at 08:15 PM.
#41
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Kelly,
Thank you the info/explanation of TEMS ramp values on the PST 600R along with the recommendation of upgrading to a FADEC ECU. I recall that David Gladwin made the same recommendation and even published it in RCJI.
Rgds,
Art ARRO.
Thank you the info/explanation of TEMS ramp values on the PST 600R along with the recommendation of upgrading to a FADEC ECU. I recall that David Gladwin made the same recommendation and even published it in RCJI.
Rgds,
Art ARRO.
#43
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No problem, happy to help. Its been many years since I was involved with PST, and TJT even further back.
A few other unusual notes to share...
- if you need to get a replacement thermocouple, I'd recommend looking to omega (http://www.omega.com/) Duplicate the dimensions from the probe you have, but make sure you get an ungrounded probe. That means the internal thermocouple should not be physically contacting the exterior of the probe body. A whole bunch of one batch of probes failed by shorting the internal probe to the body, which conducted to the engine body, which then created a ground loop with the glow and / or starter motor. Diagnosis was really weird unless you knew to look for it. The engine when berserk in the initial spin up process, before fuel ever got to it, RPM readings all over the map. In that case, if you separated the probe from the engine but left it plugged in to the cable, you'd kill the ground loop and the engine would suddenly try to start properly again (but fail to ramp from not detecting EGT rise...)
- If the engine shuts down unexpectedly, plug in the data terminal and look for an asterisk. It'll be to the right of the RPM if shaft speed went out of bounds (up or down), to the right of EGT if temperature went too high or too low. That said, with an air bubble, it might be compete to see if the EGT or RPM is the 1st to reach the lower boundary and force the shutdown... If the asterisk is sitting beside the line where the <no R/C> is shown when the receiver is off, it shut off from lost signal...
- I think default EGT shut down limits are something like ~830 and 249... You can adjust your probe to run the engine somewhere in the middle of that range for best reliability. It'll just need to see 110C or above to allow fuel to flow on start up, so that also has an effect on setting the probe depth too. (deeper into the cone reads hotter)
If I come up with anything else to share, I'll post. Don't get on much here anymore. Feel free to ask question if you have something specific. That said, just to add to the earlier recommendation. The TEMS is really kinda' like an advanced RC Car speed control. The start sequence calibrates the idle voltage. The top end calibration (when you bother to do it) sets the upper voltage. The upper and lower voltages in the throttle curve then remain more or less constant. Problem is, if you change altitude, the weather changes, the pump loosens up or gets tight, whatever, and the pilot doesn't recalibrate on the next flying day, who knows what will happen at the top end. The pilot MUST calibrate the top end. I’d recommend taking the engine up to the ½ throttle setting, then performing the auto calibration from that state. I did an auto calibration from idles once and somehow damaged the engine.
We also had some issues with bypassed 600R's on the TEMS shutting down on takeoff, and in/out of bypass in the air at full speed. The ram air effect would decrease the 'work' required to suck the air in, thus the shaft speed would go up, and the ECU would not actively recalibrate to bring it back down because it will just stick to that upper pump voltage limit from the last calibration (on the ground, at zero velocity)... In some cases it would go past the upper shut down RPM limit and execute the auto shut down. That was ~173K or something along those lines...
The FADEC does actively recalibrate, like any other ECU out there pretty much... Gaspar really knows his stuff and makes a good quality product.
Kelly
A few other unusual notes to share...
- if you need to get a replacement thermocouple, I'd recommend looking to omega (http://www.omega.com/) Duplicate the dimensions from the probe you have, but make sure you get an ungrounded probe. That means the internal thermocouple should not be physically contacting the exterior of the probe body. A whole bunch of one batch of probes failed by shorting the internal probe to the body, which conducted to the engine body, which then created a ground loop with the glow and / or starter motor. Diagnosis was really weird unless you knew to look for it. The engine when berserk in the initial spin up process, before fuel ever got to it, RPM readings all over the map. In that case, if you separated the probe from the engine but left it plugged in to the cable, you'd kill the ground loop and the engine would suddenly try to start properly again (but fail to ramp from not detecting EGT rise...)
- If the engine shuts down unexpectedly, plug in the data terminal and look for an asterisk. It'll be to the right of the RPM if shaft speed went out of bounds (up or down), to the right of EGT if temperature went too high or too low. That said, with an air bubble, it might be compete to see if the EGT or RPM is the 1st to reach the lower boundary and force the shutdown... If the asterisk is sitting beside the line where the <no R/C> is shown when the receiver is off, it shut off from lost signal...
- I think default EGT shut down limits are something like ~830 and 249... You can adjust your probe to run the engine somewhere in the middle of that range for best reliability. It'll just need to see 110C or above to allow fuel to flow on start up, so that also has an effect on setting the probe depth too. (deeper into the cone reads hotter)
If I come up with anything else to share, I'll post. Don't get on much here anymore. Feel free to ask question if you have something specific. That said, just to add to the earlier recommendation. The TEMS is really kinda' like an advanced RC Car speed control. The start sequence calibrates the idle voltage. The top end calibration (when you bother to do it) sets the upper voltage. The upper and lower voltages in the throttle curve then remain more or less constant. Problem is, if you change altitude, the weather changes, the pump loosens up or gets tight, whatever, and the pilot doesn't recalibrate on the next flying day, who knows what will happen at the top end. The pilot MUST calibrate the top end. I’d recommend taking the engine up to the ½ throttle setting, then performing the auto calibration from that state. I did an auto calibration from idles once and somehow damaged the engine.
We also had some issues with bypassed 600R's on the TEMS shutting down on takeoff, and in/out of bypass in the air at full speed. The ram air effect would decrease the 'work' required to suck the air in, thus the shaft speed would go up, and the ECU would not actively recalibrate to bring it back down because it will just stick to that upper pump voltage limit from the last calibration (on the ground, at zero velocity)... In some cases it would go past the upper shut down RPM limit and execute the auto shut down. That was ~173K or something along those lines...
The FADEC does actively recalibrate, like any other ECU out there pretty much... Gaspar really knows his stuff and makes a good quality product.
Kelly
Last edited by Kelly W; 06-30-2016 at 08:24 AM.
#44
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Kelly,
Great info for PST users and many thanks again. I'll notify a local PST operator that is experiencing reoccurring flameout problems after takeoff. Don't know if he frequents this sub-forum.
Rgds,
Art ARRO
Great info for PST users and many thanks again. I'll notify a local PST operator that is experiencing reoccurring flameout problems after takeoff. Don't know if he frequents this sub-forum.
Rgds,
Art ARRO