FT What Did You Do RC Today : Caution Offtopic At All Times

Wildthing

Legendary member
Oh no that's WAY too many channels. I bet it won't even get off the ground. :LOL:

Just finished mine. Almost wanted to film it running across the carpet, but my place is a mess!
This is gonna be good.
I may take mine for a scoot down the street but I know this foam at -15C or less it is just brittle and any hard thump it will shatter like glass. My lack of patience always costs me extra repairs :D
 

The Hangar

Fly harder!
Mentor
Well we got some snow do I took the umx J3 cub and the Sea Angel out and had some fun!
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speedbirdted

Legendary member
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I actually flew something! YAY! Underpowered, slightly tailheavy, covering coming off as it flew, but dad gummit I had something in the air!

Currently swapping the 40LA for a 46AX as I type this, repairing the covering. Ultimately I will be putting a Saito in it but that's for the future as Idon't have one on hand that will work.
My LA racer had basically that exact same set of problems on its maiden. I fixed the covering problem eventually by ripping off all of the Toughlon crap they come covered in but unfortunately I had to keep the LA engine because club 40 rules require it...

It's a real shame because with a good shot of extra horsepower it'd be a really fun airplane. I've got a Supertigre GS45 in a box somewhere that will spin the same propeller 3k rpm faster and let me get rid of the lead in the nose but then it wouldn't be legal to race anymore! :(
 
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JennyC6

Elite member
My LA racer had basically that exact same set of problems on its maiden. I fixed the covering problem eventually by ripping off all of the Toughlon crap they come covered in but unfortunately I had to keep the LA engine because club 40 rules require it...

It's a real shame because with a good shot of extra horsepower it'd be a really fun airplane. I've got a Supertigre GS45 in a box somewhere that will spin the same propeller 3k rpm faster and let me get rid of the lead in the nose but then it wouldn't be legal to race anymore! :(
Mm. I had three flights with my 4*40. Flight two was having some fuel draw issues or something I don't know. Bizarre. Acted like it was out of fuel but then not out of fuel?! Strange little engine. Stayed running though. Wasn't overheating. Maybe just break-in pains maybe something funky with the tank. If my 46AX does it too then I know it's a tank issue; the 46AX has flown before and never given me any grief. I'm not ruling out a tank issue either, given the age of the aircraft, but I'm also not ruling out an issue with that engine in particular. Another odd thing it was doing? It would lose prime almost immediately once it shut off. Made starting it a little bit more frustrating than it should have been because it basically had to reprime itself.

Given the toughness of the LA-series engines you could try shimming the head a bit and throwing more nitro down its gullet. You really can't blow one up so, as long as rules allow, feed it a witch's brew. Maybe replicate the Missile Mist of yesteryear or throw some boat fuel at it or sommat. Maybe even some car fuel, though if you do this make doubly sure it has castor in it because otherwise you'll get an airleak between the crank and its bushing. They'll never rev to save their lives(They only have two x-fer ports!) but if each power stroke hits harder you can turn more prop and thus get a bit more poke out of the aircraft.

My Long-EZ is giving me even more electrical grief though. I got the elevator servos replaced 'cause one of them stunk up the entire house with magic smoke and....well -beep- now an aileron servo is spaztastic. No magic smoke yet, but it seems I just can't win for losing with these servos. I was going to give the others benefit of the doubt and assume a factory defect took the smokebomb servo out but now I'm back to thinking the entire lot of them are defective and need replaced. So I guess I'm buying five more S3004's. Or maybe four of them and an FT 9g; throttle barrels take naff all torque to rotate so why carry a full size servo to do the job? Also need to start making a cockpit for it; I've decided my 7" Duke Nukem figure will be a perfect pilot once he's got a chair to sit in and flight controls to grab. His hands are even in the right shapes/positions! I also have an R2006GS sitting here to put in it; a Y-harness and some clever mixing gets all the servos playing nice on just 6 channels.

Also have another ship in the works. Will get a pic of it later today. Not spoiling too much(Though if you're in the FT discord you prolly already know), but what I will say now? It's a classic, it's gorgeous, it's one of the finest flying aerobats this hobby has ever seen, and it's wearing the engine my NexSTAR took to the skies over Edgewater year before last.
 

Bricks

Master member
^^^ what are you running for voltage to your receiver and servos, I like to use Life batteries but I found out many servos cannot take the voltage of them, and pooof the magic smoke.
 

JennyC6

Elite member
^^^ what are you running for voltage to your receiver and servos, I like to use Life batteries but I found out many servos cannot take the voltage of them, and pooof the magic smoke.
2s LiFE. Same voltage range as 5s NiMH/NiCD. And these are not low end ancient relics either; they're 80-90 dollar metal gear digital servos. Many...including the one that let the magic smoke out...HS5985MG which are rated for 6.0v just like the S3004s I love and use so often and which don't care one iota about 2s LiFE.
 

speedbirdted

Legendary member
Mm. I had three flights with my 4*40. Flight two was having some fuel draw issues or something I don't know. Bizarre. Acted like it was out of fuel but then not out of fuel?! Strange little engine. Stayed running though. Wasn't overheating. Maybe just break-in pains maybe something funky with the tank. If my 46AX does it too then I know it's a tank issue; the 46AX has flown before and never given me any grief. I'm not ruling out a tank issue either, given the age of the aircraft, but I'm also not ruling out an issue with that engine in particular. Another odd thing it was doing? It would lose prime almost immediately once it shut off. Made starting it a little bit more frustrating than it should have been because it basically had to reprime itself.

If it's an old tank I would suspect the clunk line has hardened and now the clunk is stuck at the back of the tank, maybe even held a little off the tank floor. At mid to low fuel levels with some sloshing you can easily get the clunk out of the fuel and cause big air bubbles in the fuel line. I would also maybe suggest the needle valve; for some reason I find the little O-ring in the LA needle valve has a propensity to become flattened down over time and the seal just disintegrates, and just like that you've got air in your fuel. Don't even bother looking for a replacement O-ring, they're unobtainium. If you use medium diameter fuel tubing in the place of that O-ring this will create a good seal but my preferred method is just to get rid of the clicker thing altogether and create a fuel tube sleeve over the seam where the valve goes into the valve body, and this will chase out any air leaks from this area for good as well as giving you sub-click precision when you go to tune your needle setting (great for racing!)

The priming issue makes me think that the tank is set too low in the fuselage. Does it still do it when the tank is full? Fuel level in the tank would have an impact on holding prime, but most of the time you only prime an engine when the tank is full.

Given the toughness of the LA-series engines you could try shimming the head a bit and throwing more nitro down its gullet. You really can't blow one up so, as long as rules allow, feed it a witch's brew. Maybe replicate the Missile Mist of yesteryear or throw some boat fuel at it or sommat. Maybe even some car fuel, though if you do this make doubly sure it has castor in it because otherwise you'll get an airleak between the crank and its bushing. They'll never rev to save their lives(They only have two x-fer ports!) but if each power stroke hits harder you can turn more prop and thus get a bit more poke out of the aircraft.

I did try that once actually. Not race legal but I figured it was worth a shot for science. I used a colder plug instead of a shim but it seemed to work just fine. I think I used a TCA #6 or 7 with some 30% Fitz 1/2A fuel and it seemed to give it a few more RPM's on the top end, but I propped it kinda slow. Not worth the cost of the high nitro fuel IMHO. I prop all my LA engines slow, since at higher speed their porting means they really start choking. My racer has an 11x7 APC and guys always wonder why I can keep up with them with such a slow turning motor. If I ever end up doing something like building an old timer with an LA engine I'll use like a 12" or 13" prop for the old timer sound too. Maybe with a head shim just to make it a lil happier at the lower speed.

Everyone uses the same fuel too, Ritch's Brew 15%. Given that most guys get their fuel through the club and that's what they get us every year they probably don't even have to supply the fuel for everyone at events, everyone will bring the same stuff anyway. They do give you the option for 15S/5C or full castor though. I usually pick the synth/castor blend but maybe I'll change it up just to see if it's any better...

My Long-EZ is giving me even more electrical grief though. I got the elevator servos replaced 'cause one of them stunk up the entire house with magic smoke and....well -beep- now an aileron servo is spaztastic. No magic smoke yet, but it seems I just can't win for losing with these servos. I was going to give the others benefit of the doubt and assume a factory defect took the smokebomb servo out but now I'm back to thinking the entire lot of them are defective and need replaced. So I guess I'm buying five more S3004's. Or maybe four of them and an FT 9g; throttle barrels take naff all torque to rotate so why carry a full size servo to do the job? Also need to start making a cockpit for it; I've decided my 7" Duke Nukem figure will be a perfect pilot once he's got a chair to sit in and flight controls to grab. His hands are even in the right shapes/positions! I also have an R2006GS sitting here to put in it; a Y-harness and some clever mixing gets all the servos playing nice on just 6 channels.

Kek I had something like that happen once. Cheapo eflite servo melted itself to death during bench testing one day. No load on it or anything. Really not sure what happened...

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I've never heard of a hitec servo doing it though. Generally the stuff they make is pretty good in terms of QC. The only other thing I can think of is maybe your RX has the type of ports that aren't entirely buried in the plastic case so there's a chance you can get the servo plugged in with reverese polarity if you both have the plug backwards and miss the plugin by one prong. I have killed servos by doing this...
 

JennyC6

Elite member
If it's an old tank I would suspect the clunk line has hardened and now the clunk is stuck at the back of the tank, maybe even held a little off the tank floor. At mid to low fuel levels with some sloshing you can easily get the clunk out of the fuel and cause big air bubbles in the fuel line.
Possibly, but that would be a MAJOR problem in inverted flight. The plane flew just as well in Australian mode as it did in American mode. The problem cropped up in steady level cruise flight which tends to make me think the problem is a bit further forward.

I had a clunk issue with Speedyboi once and it deadsticked about 3.5 seconds into a half throttle inverted pass. Clunk had gotten itself folded around to the front of the tank on a previous landing where I overran the runway and endo'd it in tall grass. Go figure.
I would also maybe suggest the needle valve; for some reason I find the little O-ring in the LA needle valve has a propensity to become flattened down over time and the seal just disintegrates, and just like that you've got air in your fuel. Don't even bother looking for a replacement O-ring, they're unobtainium.
Ye that doesn't surprise me. Might just be the case. If the problem isn't present on the 46AX I'd almost bet money on it. What boggles my mind on this, though, is that the engine has so little time on it. Pretty sure the previous owner ripped a Saito off, threw this on there, ran one tank through it just to make sure it actually ran, then sold the plane for the price of the engine.

The priming issue makes me think that the tank is set too low in the fuselage. Does it still do it when the tank is full? Fuel level in the tank would have an impact on holding prime, but most of the time you only prime an engine when the tank is full.
Yeah it does it on a full tank too. I can bring fuel up to it with just two choked flips but after about ten seconds I can see the fuel retreating back into the tank again.



I did try that once actually. Not race legal but I figured it was worth a shot for science. I used a colder plug instead of a shim but it seemed to work just fine. I think I used a TCA #6 or 7 with some 30% Fitz 1/2A fuel and it seemed to give it a few more RPM's on the top end, but I propped it kinda slow. Not worth the cost of the high nitro fuel IMHO. I prop all my LA engines slow, since at higher speed their porting means they really start choking. My racer has an 11x7 APC and guys always wonder why I can keep up with them with such a slow turning motor. If I ever end up doing something like building an old timer with an LA engine I'll use like a 12" or 13" prop for the old timer sound too. Maybe with a head shim just to make it a lil happier at the lower speed.

My thought was high nitro and high pitch 10" props. 10-10 APC for example. 40LA ain't gonna rev no matter what you do with it but I figured if you threw enough nitro at it you could pull a 10" pitch and get speed anyway. Absent that it'd be down to drag reduction but I don't know how much of that your ruleset allows since I don't have the rule book to hand.

40/46LA would be a good choice for an old timer, also a floatplane or airboat. What I'd use them for. They aren't powerhouses but they're indestructible, dependable, will tolerate abuse like nobody's business, and they'll turn shockingly large props without much fuss. A 12-4 would be a pretty good choice on an old timer or a floatplane methinks.

They'd also be a good base for a diesel conversion if a head can be found. I know Davis Diesel Development used to sell a conversion head for the 40FP which shares the same attributes(Though I think they have more aggressive porting and push more power out as a result) but I don't know about the 40/46LA.

Everyone uses the same fuel too, Ritch's Brew 15%. Given that most guys get their fuel through the club and that's what they get us every year they probably don't even have to supply the fuel for everyone at events, everyone will bring the same stuff anyway. They do give you the option for 15S/5C or full castor though. I usually pick the synth/castor blend but maybe I'll change it up just to see if it's any better...
I've heard that Rich's Brew is good -beep- but I've never run it myself since my LHS stocks Omega 15% for 25 bucks a jug. I just buy that.



Kek I had something like that happen once. Cheapo eflite servo melted itself to death during bench testing one day. No load on it or anything. Really not sure what happened...

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Just like yours it failed on the test bench in the middle of its travel range with no load on it.

I've never heard of a hitec servo doing it though. Generally the stuff they make is pretty good in terms of QC. The only other thing I can think of is maybe your RX has the type of ports that aren't entirely buried in the plastic case so there's a chance you can get the servo plugged in with reverese polarity if you both have the plug backwards and miss the plugin by one prong. I have killed servos by doing this...
I generally don't have problems with hitecs either. They're not what I go to when buying a servo but most of my used planes are loaded with them and I generally just leave them be unless they give me reason to disturb them. Speedyboi, for example, is full of Hitec 13g servos and it's one of my favorite aircraft.

My go-to servo is the venerable Futaba S3004 though. The only time I've ever broken an S3004 is when I tried to use one to steer a monster truck.
 

JennyC6

Elite member
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And this is my latest project! Tower restocked their legendarily good Kaos 40 ARFs and I jumped on it. Still need to throw electronics in it, hinge everything, and do all that final assembly fiddlededoo, but the major bits are in place. By my estimations I'll come in a few ounces underweight; 4lbs10oz to the recommended 5-6lbs. Current weight is 4lbs1oz.

Makes me wonder what a guy is doing if they build one of these and it comes in at 6lbs. I'm not even trying to save weight and I'm going to be in under 5 by a comfortable margin.

As for power...that 4-cycle there is the very same Magnum 52RFS that I had in my NexSTAR in 2019. I flew it at Edgewater for FPVFest 2019 in that plane and I will fly it at Edgewater again for FPVFest 2021. Turns an 11-7-3 prop with authority; 9750RPM last time I tached it. 5.25-5.5lbs static thrust. Should be power AND speed for days in this thing!
 

speedbirdted

Legendary member
My go-to servo is the venerable Futaba S3004 though. The only time I've ever broken an S3004 is when I tried to use one to steer a monster truck.
Can attest... own just a couple myself ;)

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In all including the 3001 through to the 3004 I own probably 75 of the things. Never had an in-service failure, only times I've encountered a broken one was as the result of a crash and everything around it was equally fubar as well. Pretty much all my gas planes with the exception of the racer use them (and the only reason that one doesn't have em is because it came to me with real nice Savox metal gear jobs preinstalled)

unknown.png

And this is my latest project! Tower restocked their legendarily good Kaos 40 ARFs and I jumped on it. Still need to throw electronics in it, hinge everything, and do all that final assembly fiddlededoo, but the major bits are in place. By my estimations I'll come in a few ounces underweight; 4lbs10oz to the recommended 5-6lbs. Current weight is 4lbs1oz.

Makes me wonder what a guy is doing if they build one of these and it comes in at 6lbs. I'm not even trying to save weight and I'm going to be in under 5 by a comfortable margin.

ooooOOOOOooo I like. I really ought to get another Kaos sometime. I had a Kaos 60 as my first "acro" fuel plane. Came to me with an old 72 radio installed in it, worked perfectly fine so I didn't care to change it out. All the electronics in it had to be at least 30 years old. It had a Magnum 70 in the nose which gave it near-unlimited vertical. It was a real fun airplane until I had a RUD as a result of a loop with insufficient altitude :p

Usually excessive weight is because of bad wood. Overgluing can cause it to a degree but glue really doesn't weigh much by itself. Using the wrong kind of componentry also can cause it (too big of servos is one I see a lot) There's also guys who would come in at the target weight but then need half the AUW in balance weight to get it to fly right...

As for power...that 4-cycle there is the very same Magnum 52RFS that I had in my NexSTAR in 2019. I flew it at Edgewater for FPVFest 2019 in that plane and I will fly it at Edgewater again for FPVFest 2021. Turns an 11-7-3 prop with authority; 9750RPM last time I tached it. 5.25-5.5lbs static thrust. Should be power AND speed for days in this thing!

Funnily enough I actually just got a few MAS 11x7 3 blades in the mail for my 52RFS. I have one on an Avistar which previously swung an APC 11x7. On the ground I think I tached it at about 9600 but I could tell by ear it was unloading to probably 12,000+ in the air. Maybe that's why this happened:

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In retrospect I'm lucky it even lasted as long as it did. Probably it's because this engine only very rarely saw full throttle, half was plenty for most maneuvers I did with it. Surprisingly other than the crankpin going on a bit of an adventure the engine is fine. There's not even a dent in the crankcase where the conrod was impeded from its otherwise unrestricted downward trajectory after the crankpin and shaft parted ways. I know it happened on the downstroke as there's no dents in the top of the piston from it hitting the valves, and the valves themselves look fine too. I'm thinking all I need is a new shaft and this engine will be good to go. Some digging revealed the OS Surpass shaft will fit so that's what it'll get swapped with. I acknowledge my treatment of it wasn't exactly the best but I'm betting some sort of manufacturing error was also present here because I've NEVER heard of this happening to an engine with a solid crankpin. Only the ones with hollow pressed pins do it on occasion...
 

JennyC6

Elite member
Can attest... own just a couple myself ;)

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In all including the 3001 through to the 3004 I own probably 75 of the things. Never had an in-service failure, only times I've encountered a broken one was as the result of a crash and everything around it was equally fubar as well. Pretty much all my gas planes with the exception of the racer use them (and the only reason that one doesn't have em is because it came to me with real nice Savox metal gear jobs preinstalled)

People like to give them crap because they're plastic geared, or because they're not sporting superlative specs...they're 13 bucks a piece and dependable as can be! What's not to like? And it's not like you need 0.07s/60 in a plane when you're moving the servo maybe 10 degrees for normal aerobatic flight. I can see 3D guys going full throw often but for just boring holes in the sky the S3004 is fine.



ooooOOOOOooo I like. I really ought to get another Kaos sometime. I had a Kaos 60 as my first "acro" fuel plane. Came to me with an old 72 radio installed in it, worked perfectly fine so I didn't care to change it out. All the electronics in it had to be at least 30 years old. It had a Magnum 70 in the nose which gave it near-unlimited vertical. It was a real fun airplane until I had a RUD as a result of a loop with insufficient altitude :p
Yeah lithobraking tends to be problematic with regard to aircraft survival.
Usually excessive weight is because of bad wood. Overgluing can cause it to a degree but glue really doesn't weigh much by itself. Using the wrong kind of componentry also can cause it (too big of servos is one I see a lot)
A lot of that isn't really possible here given it's an ARF, though you could splurge on the aluminum with everything I suppose. And use nickel batteries to power the receiver.



There's also guys who would come in at the target weight but then need half the AUW in balance weight to get it to fly right...

These are also the guys that think you need a 60 2c on a 40-size airframe...or a 90 4c...and get indignant when you point out that a properly sized engine still gives infinite vertical without turning the thing into a lead sled.

I always err towards the smallest engine I can fit to the plane that will give it the flight envelope I want for it. To be honest this Magnum 52 will be a bit too much power given how light it's gonna come out.


Funnily enough I actually just got a few MAS 11x7 3 blades in the mail for my 52RFS. I have one on an Avistar which previously swung an APC 11x7. On the ground I think I tached it at about 9600 but I could tell by ear it was unloading to probably 12,000+ in the air. Maybe that's why this happened:

View attachment 192341

In retrospect I'm lucky it even lasted as long as it did. Probably it's because this engine only very rarely saw full throttle, half was plenty for most maneuvers I did with it. Surprisingly other than the crankpin going on a bit of an adventure the engine is fine. There's not even a dent in the crankcase where the conrod was impeded from its otherwise unrestricted downward trajectory after the crankpin and shaft parted ways. I know it happened on the downstroke as there's no dents in the top of the piston from it hitting the valves, and the valves themselves look fine too. I'm thinking all I need is a new shaft and this engine will be good to go. Some digging revealed the OS Surpass shaft will fit so that's what it'll get swapped with. I acknowledge my treatment of it wasn't exactly the best but I'm betting some sort of manufacturing error was also present here because I've NEVER heard of this happening to an engine with a solid crankpin. Only the ones with hollow pressed pins do it on occasion...
I've heard OS FS48s are bad about that but not the Magnum 52s. And I think mine might be rev limited anyway; I get the same static revs on an 11-7-8 as well and that implies to me that the thing just can't breathe trying to spin any faster. Valve float.

Might be interesting to throw a T-FHSS receiver and a tacho in the Kaos just to see what sorta revs I get in flight. Wouldn't mind an IAS sensor but I don't know if Futaba telemetry has one.

As for why yours didn't dent the case...I'd almost bet money the rod was already so close to the case that the castor oil in there was filming up between teh two parts when the pin sheared off, so it had a very glancing blow and just sorta slid around the curve. It also looks like it was cracked for a while judging by the way the shear looks. The dull area would have been exposed to the environment inside the case for a while before the pin finally snapped off.
 

mrjdstewart

Legendary member
the new short course truck was a blast. finished the first run battery to make sure the brushes were set in, then hit it on the 2nd battery. member brought a ramp he built and we spent some time flying, then worked out a little oval track. it has been a long time since i have done any fast ground RC and was quickly reminded of how nuts it can be, especially at speed. super fun and so happy so far.

came home from field and started working on this...

20210213_130214.jpg


plan is 2x Emax 2205-2300 Red Bottoms w/6x4.5 props, 2x 20A ESC, 2x 3S-800.

only hitch at this point is i need to 3D print the firewalls to match my motor and unfortunately the printer is 20hrs into a 30hr print.

20210213_175333.jpg


gonna be a little bit before it is free to print these.

Screen Shot 2021-02-13 at 4.00.55 PM.png


looks like rain possible for tomorrow so may be nothing but trucks. today we sketched out the oval and a possible corse. we are lucky our club has plenty of space to do what we want. the outline is a proposed new course with the black eye being the oval course. gonna call it the Amoeba Course.

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laters,

me :cool:
 

JennyC6

Elite member
the new short course truck was a blast. finished the first run battery to make sure the brushes were set in, then hit it on the 2nd battery. member brought a ramp he built and we spent some time flying, then worked out a little oval track. it has been a long time since i have done any fast ground RC and was quickly reminded of how nuts it can be, especially at speed. super fun and so happy so far.

came home from field and started working on this...

View attachment 192338

plan is 2x Emax 2205-2300 Red Bottoms w/6x4.5 props, 2x 20A ESC, 2x 3S-800.

only hitch at this point is i need to 3D print the firewalls to match my motor and unfortunately the printer is 20hrs into a 30hr print.

View attachment 192356

gonna be a little bit before it is free to print these.

View attachment 192343

looks like rain possible for tomorrow so may be nothing but trucks. today we sketched out the oval and a possible corse. we are lucky our club has plenty of space to do what we want. the outline is a proposed new course with the black eye being the oval course. gonna call it the Amoeba Course.

View attachment 192360

laters,

me :cool:
Ground stuff is hella fun especially when you can't fly for one reason or another. Why I run both!
 

The Hangar

Fly harder!
Mentor
The sea angel looks great. How well does it fly? I imagine there would be some pitch coupling with throttle?
There’s a little bit of coupling but not too bad. I actually was able to fly it around as a 2ch (throttle and rudder) and get some footage with the other hand last time it snowed. It flies best at lower throttle, but full throttle is very controllable, just a little wonky.
 

JennyC6

Elite member
Funnily enough I actually just got a few MAS 11x7 3 blades in the mail for my 52RFS. I have one on an Avistar which previously swung an APC 11x7. On the ground I think I tached it at about 9600 but I could tell by ear it was unloading to probably 12,000+ in the air.
Did a little digging on Futaba's website and, hey presto, pitot tube for SBus 2 telemetry. Optical tacho. Engine temp sensor that's OOS(Prolly put this on my Long-EZ Since pushers are more prone to overheating).

I forsee a lot of telemetry shenanigans in my future~