Go Back  RCU Forums > RC Airplanes > Questions and Answers
Reload this Page >

Just scored big at the LHS. What the hell did I buy?!

Questions and Answers If you have general RC questions or answers discuss it here.

Just scored big at the LHS. What the hell did I buy?!

Reply

Old 07-09-2019, 06:40 PM
  #1  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default Just scored big at the LHS. What the hell did I buy?!


Picked this thing up from my LHS, TxR, $40. Siezed OS 40FP on the nose. Got it home and within 2 hours I had the engine running pretty much flawlessly at anything north of 1/4 throttle. Need to run it some more, get the low end dialed in so itt'l idle nice, then give it a modern 2.4g receiver, a modern LiFE Rx pack, and get it in the air!


Perchance, anyone know what this thing is? The guys in the Glow Nation FB think it's a Midwest Aerostar 40 trainer.
378 is offline  
Reply With Quote
Old 07-09-2019, 07:25 PM
  #2  
maukaonyx
 
Join Date: Oct 2006
Location: salem, OR
Posts: 1,286
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I agree....I built the Aerostar 20 which looks the same except for size. It’s a good flying plane.
maukaonyx is offline  
Reply With Quote
Old 07-10-2019, 05:32 PM
  #3  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default


It runs great! Got the low end dialed in, passes the 'nose up' test with flying colors...I'm satisfied that, if I put a 2.4ghz receiver and a Li-FE pack in this thing, the plane would fly as well as it ever did.
378 is offline  
Reply With Quote
Old 07-10-2019, 09:45 PM
  #4  
Hydro Junkie
 
Join Date: Nov 2004
Location: Marysville, WA
Posts: 7,640
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

You done good. In most cases, the engine alone would cost you that much. That said, I have three recommendations for you:
1) Remove the engine and mount and refinish the nose of the plane. I saw what looked like bare wood and, if that is the case, it would soak up oil rather quickly, destroying the structure.
2) If you remove the engine, I'd tear it down and soak the case in warm used antifreeze. It will, when used with a nylon brush, remove all the grime from the outside of the case which will allow the engine to cool more efficiently. An old, small crock pot would work well in this situation.
3) I'd replace the prop and spinner. Both look fairly beat up and, since you don't know if the prop has ever had a ground strike, it would probably be a good idea to get new one of each, balance it and install them.
Hydro Junkie is online now  
Reply With Quote
Old 07-10-2019, 10:19 PM
  #5  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by Hydro Junkie View Post
You done good. In most cases, the engine alone would cost you that much.
Current going rate for a running 40FP on eBay is 50 bucks shipped, so yeah. Guess you could say I got a free airplane with the purchase of a used OS engine haha~ [quote]
1) Remove the engine and mount and refinish the nose of the plane. I saw what looked like bare wood and, if that is the case, it would soak up oil rather quickly, destroying the structure.
It is bare wood in there, and it appears to have been bare wood for a very long time. It's...hard to tell if this thing's ever actually flown, truth be told. The engine's been run for sure and certain...they don't get schmoo'd up like this just sitting on a shelf...but I can't find any evidence of it having been crashed nor am I finding oil stains in the nose.

FWIW it had an ANCIENT Futaba receiver in it when I got it. 1/2a glow clip with D-cells in it for scale.



Those are adapter cables to allow modern servos to plug into this thing. It's got four reasonably modern servos and they all move freely. I'll know whether they're functional or not when I get an R2006GF in there and get it bound to my 6J. If there's any question regarding their health, I have a full set of brand new S3004s sitting on my desk. They'll be fine in a plane like this.

2) If you remove the engine, I'd tear it down and soak the case in warm used antifreeze. It will, when used with a nylon brush, remove all the grime from the outside of the case which will allow the engine to cool more efficiently. An old, small crock pot would work well in this situation.
Yeah I checked temps when I was running it. Idle temps in at about 250 degrees, and if I let it scream, it creeps up and stabilizes at somewhere around 325-335. Bit hot, but not excessively so. Factoring in the reduced airflow from it not being in flight, it should temp in nice once it's been cleaned off.

Regarding cleaning it, my plan was to get some brass wire wheels for my dremel, set it to its lowest setting, and run that between the fins. Shouldn't mar up the aluminum any. I'm a bit hesitant to pull the backplate on this thing at the moment. It doesn't use an o-ring for a seal here and if I tear the paper gasket it currently has itt'l never run right until a new gasket is fitted. Shouldn't be too hard to track a gasket down, but until I've got one on hand I'm not keen on popping the backplate off.

I didn't film them, but I did do inverted(With <1/4 tank in it) and nose-high WOT tests. It didn't care. The tank is still sealed up well, the clunk is still clunking as it should. Ran an entire tank through it today, more or less, and I only started it once.


3) I'd replace the prop and spinner. Both look fairly beat up and, since you don't know if the prop has ever had a ground strike, it would probably be a good idea to get new one of each, balance it and install them.
I was thinking of swapping the spinner out for a big brass prop nut anyway. The PO had put a bundle of 2 inch brad nails in the nose weighing something close to a pound for CG purposes anyway, and I'd rather have less weight mounted farther forward. Why carry a pound of nails just under the rear end of the fuel tank when a few ounces of brass right on the nose gets it balanced?

Spinner appears to have wear from e-starter use. I noticed pretty quick that this thing has its own wants regarding startup. I tried to start it like I start my 46AX and it didn't even pop. It draws fuel up to the carb just fine, but if you stop priming it when the fuel hits the carb and start flipping to start you get nothing. However, if you damn near flood it, it fires off on the first flip. I'm guessing the previous owner never found the 'combination' and resorted to an e-starter instead. Need to pull the prop anyway to get sizing info on it; I have no idea what the pitch is but if I were to guess I'd say it's a 10-6 or 10-7. I do know the engine pulls strong on it, so it's getting the same size prop put back on either way.

Last edited by 378; 07-10-2019 at 10:24 PM.
378 is offline  
Reply With Quote
Old 07-11-2019, 08:00 AM
  #6  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,799
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

It's fairly common for a plain bearing engine to require a bit more prime for starting then a BB engine. If it has sat for a while it will need the additional fuel to establish a film seal between the crankshaft and the bushing/crankcase. Once the seal is established it will draw fuel up into the combustion chamber more efficiently. Great score though, one thing I have not had around for a while is a small trainer, I miss having something to just take out and fly for the heck of it. Enjoy.
speedracerntrixie is offline  
Reply With Quote
Old 07-11-2019, 08:05 AM
  #7  
JohnBuckner
My Feedback: (1)
 
JohnBuckner's Avatar
 
Join Date: Dec 2001
Location: Kingman, AZ
Posts: 10,402
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Indeed, maukaonyx is correct although it is the Midwest Aerostar 40. Built in two sizes forty and twenty all were kits that I am aware of . It is a fine trainer and my second choice only to the Sig Senior Kaydet Long ago I used one with fifty ounces of fuel for my personal best cross country along seventyfive miles of Route 66.

No modifications at all are required so do not get caught up in that game. FP's along with the later FX.s and the more recent AX,' s are absolutely at the top of my favorite glow engines and yes even over the Four strokes.

The carb on all sizes of the FP's is a bleeder type, An example of simplicity. Very easy to set midrange but is backward from the double needle types ( Leaning midrange is done by opening the screw, not closing). I would be pleased to explain a very simple method if interested?

John
JohnBuckner is offline  
Reply With Quote
Old 07-11-2019, 08:58 AM
  #8  
JohnBuckner
My Feedback: (1)
 
JohnBuckner's Avatar
 
Join Date: Dec 2001
Location: Kingman, AZ
Posts: 10,402
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Now onto the RC system This receiver is most definitely an early Futaba AM type not an FM, Which is Very wideband which makes it illegal to use as such. It cannot be convertible to any modern (legal) standards

The battery packs are: an early futaba 4.8v 500mah Nicd. get rid of it. The other pack is not for the RC system, Perhaps it was intended as some sort of fulltime/switched glow booster. That's rubbish. The FP's are the most reliable and least in need of any glow boost, Ever.

The Servo Plugs are the Futaba (G) which were last used in 1986, They are not compatible with anything due to uneven pin spacing. As one of the fellows stated the adapters (G plug to J plug) have been out there but at what price for what you end up with? There is a "Cheat" which involves cutting the lead and replacing with an old/new J plug being very careful to get the power polarity right. If done wrong this will let the smoke out of the Rx.

One last though I would heed Hydro's suggestion to trash that spinner it is so damaged (starter cone burned) as well as aged (lost to much moisture) that is just waiting to explode wheather when starting or as sometime happens in flight.

John
JohnBuckner is offline  
Reply With Quote
Old 07-11-2019, 12:42 PM
  #9  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by speedracerntrixie View Post
It's fairly common for a plain bearing engine to require a bit more prime for starting then a BB engine. If it has sat for a while it will need the additional fuel to establish a film seal between the crankshaft and the bushing/crankcase. Once the seal is established it will draw fuel up into the combustion chamber more efficiently. Great score though, one thing I have not had around for a while is a small trainer, I miss having something to just take out and fly for the heck of it. Enjoy.
Hehe, glad to hear it's gonna fly great. 3 for 3 on smooth flying planes in my fleet, it seems. My NexSTAR is the same way, as is my FT Commuter 049. The Commuter, sporting a choketube throttle equipped Cox 0.049 reedie, solo'd me for the first time!

Originally Posted by JohnBuckner View Post
Indeed, maukaonyx is correct although it is the Midwest Aerostar 40. Built in two sizes forty and twenty all were kits that I am aware of . It is a fine trainer and my second choice only to the Sig Senior Kaydet Long ago I used one with fifty ounces of fuel for my personal best cross country along seventyfive miles of Route 66.

No modifications at all are required so do not get caught up in that game. FP's along with the later FX.s and the more recent AX,' s are absolutely at the top of my favorite glow engines and yes even over the Four strokes.

The carb on all sizes of the FP's is a bleeder type, An example of simplicity. Very easy to set midrange but is backward from the double needle types ( Leaning midrange is done by opening the screw, not closing). I would be pleased to explain a very simple method if interested?

John
The only modification I'd ever make to this engine would be getting the crankcase and cylinder head anodized to match the livery. A nice cherry red would look amazing I think, so would having a flat black crankcase with a gold head. As far as operation is concerned, it's a gem right as it is. Figured out getting the low-speed dialed in pretty quick, as the videos can tell.

I'm impressed with how broad the needle settings are, too. I can go half a turn on the high speed before the thing reacts! Great plume of blue out the back(I fumigated my mailbox with this thing from across the street hahahaha), no missed cycles, and a needle that practically sets itself. Gotta love it. And the LSN...I gave it a half-turn-in from where I had set it when I cleaned the carb and that was dead nuts on. Thing idles down to 2750RPM like it's nothing and transitions flawlessly even after burbling over for a minute or two.

Always have loved OS power. My 18 CV-RX is an absolute brute, my 46AX is boss, and now this 40FP goes from 'siezed solid' to 'fine runner' with a bit of 3'n'1 oil chased by 1/2a fuel and 2hrs of wiggling.

And yeah, I definitely buy the 'plain bearing film seal' angle, because my Cox engines are the same exact way. They tend to not start at all unless they're literally puking out the exhaust slits.

Originally Posted by JohnBuckner View Post
Now onto the RC system This receiver is most definitely an early Futaba AM type not an FM, Which is Very wideband which makes it illegal to use as such. It cannot be convertible to any modern (legal) standards

The battery packs are: an early futaba 4.8v 500mah Nicd. get rid of it.
Oh trust me I'm not using either of those. They're going on the collectible shelf as antiques. I'm putting a modern S-FHSS 2.4ghz receiver and a 2s 2200 Li-FE Rx pack in this thing and I'll be flying it on my Futaba 6J transmitter. Servos I may keep if they work properly, though. They have modern plugs on them(You can see the adapter cables still in the old Rx in my pic).

The other pack is not for the RC system, Perhaps it was intended as some sort of fulltime/switched glow booster. That's rubbish. The FP's are the most reliable and least in need of any glow boost, Ever.
The other pack is my 1/2A glow clip, which is there purely for scale purposes. Incidentally, it will also start 40 size plane engines. This thing.

It's astonishing how enormous that receiver is for only being 4 channels. Something that footprint from the last 3 or 4 years would have 20+ channels, two-way comms, built-in 6-axis gyrostabilization, rudimentary autopilot capabilities, telemetry feedback, the works.

As for my Aerostar 40...in all likelihood, itt'l get the same Rx I have in my NexSTAR, an R2006GS. I don't need anything fancy in here, just a dependable S-FHSS full-range receiver. The servos in the plane currently use standard J connectors, and if they don't work, I have four brand new S3004s sitting here waiting to go into something.

The Servo Plugs are the Futaba (G) which were last used in 1986, They are not compatible with anything due to uneven pin spacing. As one of the fellows stated the adapters (G plug to J plug) have been out there but at what price for what you end up with? There is a "Cheat" which involves cutting the lead and replacing with an old/new J plug being very careful to get the power polarity right. If done wrong this will let the smoke out of the Rx.
\

Yeah, puts a decent datestamp on the airplane. I found a manual for the 40FP; copyright 1987, and the receiver that was in it uses depreciated servo connectors that were obsoleted earlier than that. Plane was prolly built in the early 80s. Makes it older than I am!

One last though I would heed Hydro's suggestion to trash that spinner it is so damaged (starter cone burned) as well as aged (lost to much moisture) that is just waiting to explode wheather when starting or as sometime happens in flight.

John
Given that, and the amount of nose weight this thing will need, I'll probably ditch the spinner entirely and replace it with a brass prop nut. This one had a pound or so of brad nails bundled up in foam beneath the fuel tank alongside that nicd pack and the Rx, and a few other guys I've talked to about this thing that have one of their own report needing a TON of nose weight. One guy cast two lead blocks and put 'em in the cheeks right behind the prop to get his balanced.

I'd rather use less weight with more leverage to get the CG right, yanno? If 5oz of brass on the end of the crankshaft balances it as well as 16oz of nails under the back end of the fuel tank does, I'm saving 11oz of weight!

Last edited by 378; 07-11-2019 at 12:45 PM.
378 is offline  
Reply With Quote
Old 07-11-2019, 02:18 PM
  #10  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,799
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

It was very common back in the day to have the CG too far forward. Many of us ( myself included ) had it beat into our heads that a forward CG was more stable. Not entirely true but not entirely false either. What the forward CG does is mandate some up trim. On the plus side that up trim would help self correct if you started to build too much speed in a shallow dive. On the negitive side it also ment that the pitch trim would only be correct at one given airspeed and while using excessive elevator throw to compensate you can cause a nasty tip stall. Moving the CG back compensates for the drifting pitch trim some. With some fiddling between CG and downthrust you can almost eliminate it completely. All depends on what your preferences would be. I would personally set the CG to 30% and elevator throw to around 15 degrees.
speedracerntrixie is offline  
Reply With Quote
Old 07-11-2019, 02:31 PM
  #11  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Someone on the Flite Test forums has one he built 25+ years ago, showed me a pic of the plans for the fuse. CG is supposed to be 3" back from the leading edge on it according to the plans for the kit. He's also the guy that had to make lead blocks to mount on the cheeks right behind the prop to balance it.

I reckon that's a fine starting point. If I find it needs a lot of up trip to fly level I'll prolly shift the weight around a bit. My preferences are to a plane that flies like it's on rails with no twitchy tendencies; I am a novice pilot after all. Much as I'd love to have a nimble warbird or aerobat, I probably wouldn't be able to control such a plane quite yet haha.
378 is offline  
Reply With Quote
Old 07-11-2019, 03:05 PM
  #12  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,799
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Contrary to popular belief, having the CG back a little from where the plans show does not lead to an airplane that is any more nimble or twitchy. It simply makes it where the pitch trim remains more constant. It will also lower the stall speed. At 3" behind the leading edge I would expect a wing cord of around 9.5".
speedracerntrixie is offline  
Reply With Quote
Old 07-11-2019, 03:14 PM
  #13  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by speedracerntrixie View Post
Contrary to popular belief, having the CG back a little from where the plans show does not lead to an airplane that is any more nimble or twitchy. It simply makes it where the pitch trim remains more constant. It will also lower the stall speed. At 3" behind the leading edge I would expect a wing cord of around 9.5".
10 7/8" if my tape measure is accurate.
378 is offline  
Reply With Quote
Old 07-11-2019, 03:22 PM
  #14  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,799
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

That puts you less then 25% with the 3" if my headmath is correct. I would put that into the overly nose heavy column. I would go 3.5". Of course your choice, I just feel you would be happier with it based on your " on rails " preference stated earlier.
speedracerntrixie is offline  
Reply With Quote
Old 07-11-2019, 03:46 PM
  #15  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Mmn. yeah it basically needs to fly itself passively. Lemme throw the wing on, bolt it down, and see whereabouts it balanced in its previous life.
378 is offline  
Reply With Quote
Old 07-11-2019, 04:22 PM
  #16  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Hah. PO had it balanced roundabouts where you're saying to balance it.
378 is offline  
Reply With Quote
Old 07-11-2019, 04:30 PM
  #17  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,799
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Nice!
speedracerntrixie is offline  
Reply With Quote
Old 07-11-2019, 04:41 PM
  #18  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Huh. Apparently this thing's needing ballast so much because the 40FP is far too light for the airframe, that it was designed for a dual ball bearing engine rather than a plain bearing engine. And now I'm tempted to try to find an FS-52 Surpass for it, recycle the 40FP into another airframe. Ahh, future plans~~

But yah, if the PO balanced it 3.5" back, I'm gonna go ahead and keep it there. I can find no evidence of crash damage on it anywhere so it clearly likes that CG. Might see where things fall with the modern receiver pack, receiver in there before I commit to a weighted spinner/prop nut...might also be fun to put FPV on the thing, which would also lessen the need for dead ballast weight. For now, though, I'm getting it in the air again. Fancy things come later.

Last edited by 378; 07-11-2019 at 04:44 PM.
378 is offline  
Reply With Quote
Old 07-11-2019, 07:23 PM
  #19  
tedsander
 
Join Date: Jul 2004
Location: White Bear lake, MN
Posts: 100
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Presumably the servos are from around the late 80's also. You may want to consider getting a voltage regulator in line with the LiFe pack, keeping it around 5 volts. Many of the older electronic items were not very tolerant of being fed much more than what a 4.8v Nicad could put out, hot off the charger. Likely they will be swapped out real soon, anyway - probably very "economy" models from back in the day, meaning no bearings except for the plastic case, pretty low power, prone to dirty pot issues, etc.

The Aerostar, while sold as a "beginner" plane, is a really good flyer - you'll have a lot of fun with it!
tedsander is offline  
Reply With Quote
Old 07-11-2019, 10:03 PM
  #20  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Originally Posted by tedsander View Post
Presumably the servos are from around the late 80's also. You may want to consider getting a voltage regulator in line with the LiFe pack, keeping it around 5 volts. Many of the older electronic items were not very tolerant of being fed much more than what a 4.8v Nicad could put out, hot off the charger.
FP-S148 x4. They're much newer than the receiver and have standard J plugs on them. Incidentally, this also means I have four 3" long J to G adapter cables!

Servos themselves...Tower still has a listing for them and they have ratings for 6 volts. Won't burn out because of a Li-FE.
Likely they will be swapped out real soon, anyway - probably very "economy" models from back in the day, meaning no bearings except for the plastic case, pretty low power, prone to dirty pot issues, etc.
they'd be getting replaced with S3004's anyway. If these servos are in working condition there's no reason not to run them.

The Aerostar, while sold as a "beginner" plane, is a really good flyer - you'll have a lot of fun with it!
Whoooo~!

'Tis worth noting that this one was built with barely any dihedral. If it has any at all, it's only a degree or two. My FT Commuter 049 has about 5 degrees or so, enough to visibly see it, and my NexSTAR has so much you can fly it like a 3 channel by merely not touching the ailerons. Should be a good platform to learn basic aerobatics on!
378 is offline  
Reply With Quote
Old 07-12-2019, 06:22 AM
  #21  
speedracerntrixie
My Feedback: (29)
 
speedracerntrixie's Avatar
 
Join Date: Jun 2010
Location: Sacramento, CA
Posts: 6,799
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

Back in the 1980's I worked at Northern Californias largest hobby shop. We used to set up some of the off-road R/C cars with servo power coming straight from the motor battery pack. At the beginning of the run the S148 servos would be getting a tad over 8 volts. Never smoked one. They will be perfectly fine with 6.5 volts. I used to set up my Hirobo Shuttle helicopters with the same servos and 5 cell nicad packs, the additional voltage would spin the gyro faster for faster gyro response.
speedracerntrixie is offline  
Reply With Quote
Old 07-12-2019, 02:46 PM
  #22  
tedsander
 
Join Date: Jul 2004
Location: White Bear lake, MN
Posts: 100
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I still have a bunch of 148's in the "old servo" box. True, likely not much will happen to them, but...they were/are Futaba's lowest end servos. While I too ran 5 cell NiCad packs with them, note that 4 cell NiCads can produce up to 5.8v right off of charge. Five can go to 7.25. LiFe's can be 7.3. So while rated for "6v", they get pushed to up to 50% higher than the nominal 4.8v they were originally designed for. This is, of course, only for perhaps the first flight or so, and then the packs settle down to their rated voltage. I have seen premature death due to higher voltages back in the 5 cell days, but it was pretty rare. The biggest issue with those servos was that they used the hole in the case top as a bearing. The hole would elongate due to wear over time, and the servos would get worse and worse at holding neutral as the shafts rocked back and forth under load. I may still have a few that were retrofitted with aftermarket ball bearing case tops....but that didn't really improve them all that much. Best use would be for throttle only.
tedsander is offline  
Reply With Quote
Old 07-12-2019, 05:27 PM
  #23  
378
Thread Starter
My Feedback: (4)
 
378's Avatar
 
Join Date: Jan 2004
Location: Lebanon, TN
Posts: 2,849
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I will evaluate the servos and decide whether to replace them when I get a receiver and receiver battery put in it. I've got four S3004s sitting in my parts bin that are brand new, but I'm not going to disturb the linkages and risk cracking the 40 year old servo tray if I don't have to.
378 is offline  
Reply With Quote
Old 07-16-2019, 03:27 PM
  #24  
red head
 
Join Date: Feb 2005
Location: Zephyrhills, FL
Posts: 2,088
Gallery
My Gallery
Models
My Models
Ratings
My Feedback
Default

I still have 4 Aero Stars , a 60 size with an OS 90, 2- 40 size, one with a 52 and one with a 56 . And the one I fly now is a 20 size with an electric motor . The glow jobs just hang on the wall enjoying retirement . Red
red head is offline  
Reply With Quote

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service