Suggestions on old trainer?

Jan 10, 2004 23 Replies

Hey all, Mike the newbie here. I just scored an old (err, maybe 80's or 90's vintage) .40 sized trainer plane from a friend. Long story short, His friend gave it to him when he moved on to bigger and faster planes. My friend gives it to me because he's too chicken to fly it. Seriously.



Anyway, she aint pretty. Monokote was hack to begin with, and repaired a few times - poorly. Engine is not mounted and appears to be an almost-unused OS fp-35. Looks super clean, but antique. Also, the engine mount has a different hole pattern, so this wasnt her actual engine. Radio is definately '80's. Futaba FP-t6FG with the gold anodized case, but no gold sticker. (4) Fut fp-s28 servos. Nothing tested yet. Very low expectations, ecxept for possibly the engine.



my initial plan is to dremel the engine mount to make the old OS fit. Scrap the radio (any bidders?) and get another flight pack for my new futaba 4yf. Leave the monokote alone for now, i'll just make it worse soon enough.



Any other opinions/recommendations? thanks, mike the newbie.


The radio is one of the best ever built. It doesn't need a sticker because all Futaba FM sets met the requirements. The stickers were just to show which ones were good and which ones weren't during the few years around

1991. This radio uses a replaceable transmitter module. If it is an AM module, then get an FM module and you will be OK. Some were built with an easily replaceable module, others just had a bump on the back of the case. If yours has the bump, then the module is inside and you need to take the back off to replace it. The battery is probably shot by now but a new one shouldn't be much over $20.

The engine is a very good one for its size. Take care of it!

As far as the plane goes, you are on your own there!

What he said, but I wanted to add that I wouldn't trust those servos. There are many cheap ones for less than 10 bucks a piece that would be much safer to use. At least get 3 for the primary surfaces. The wipers are sure to be noisy, and the motors iffy. Check the trainer good for fuel damage of the glue joints around the nose.

Really? interesting. Its Am, i dont really care, until it starts glitching. Ive driven my cars at my local park for a couple years now with no RFI though. I suppose if the radio doesnt work, well....it was a free plane anyway. Good to hear that the engine is a keeper. Its a fairly heavy .40 size plane, i just hope the .35 will carry it around with enough authority to drag me outta stalls & mistakes.

So, unless anyone else disagrees, ill clean her up, break-in the engine and see how well she crashes. Thanks, mike

If it is AM, then it is illegal to use because it doesn't meet FCC requirements.

Hi,

Also look at this thread :

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Olivier

My problem is that the servos & rx have the old 3pin plugs. Sure, id love to swap em', but im not keen on splicing the old connectors on. I guess it would be worth it though... As for the nose, well i have to tear it apart anyway it seems. the motor is mounted to a horizontal ply deck - which was cut out and drilled for a .40. The apparently new .35 doesnt make up to the hole pattern. Gotta make a new deck. Thanks for the tip - i'll check it good.

swap em', but

My PT 40 has the same motor mount system, only the ply plate is bolted onto the hardwood bearers. If your plate is glued in, you can make a plate that bolts over the one you have in there. Saves the cutting out, and the minor change in the engine height won't affect anything. If you decide to go with a newer motor later on, it will make the change easy, since you will just have to remove the plate. Check your throttle pushrod location to see if this is feasible.

How to solve your radio issue is up to you. If you've got the money, sell the old system on ebay and get a new one. About a hundred bucks difference. You're easily going to spend half that getting the old one up to snuff with transmitter module and batteries, and that still leaves you with iffy servos.

Ive driven my

Mike, I disagree.

The lack of a gold sticker would indicate that your Futaba FG series AM TX apparently was never upgraded to be narrow band and you probably have a wide band RX too. As of 1998 it is no longer possible to have the TX upgraded.See Futaba's FAQ:

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I don't give a hoot if ya want to go out and see "how well she crashes" as long as it is just you...all alone in a remote area.

However, if you are flying at a site with other RC pilots and/or spectators or near populated areas, there are some major considerations:

1) Possibility of interference to your aircraft causing loss of control leading to injury, death, or property damage.

2) Possibility of your wide band TX interfering with another aircraft, causing loss of control leading to injury, death, or property damage. ( If you shoot down a fellow RC'ers aircraft, the injury or death may be yours. :) )

3) If you are an AMA member flying at an any AMA chartered field, use of wide band equipment violates your agreement to abide by AMA rules at the site. In any case, no matter where you fly it, the wide band will void AMA's insurance. Then if any of the above happens, you are really screwed.

If you fly it, and all seems ok, don't expect that to always be the case. The equipment present at your site will change from day to day.

This model doesn't need to be upgraded. Simply buy an FM transmitter module and you are set. They are all narrow band.

Yeah, i just bought a futaba 4yf for my electric plane, i may as well spring for another flight pak. A free plane that cost $100 for a radio still is a pretty good deal.

RCFlyr Wrote:

Wrong!!! AM is still legal to use if it is narrow band! The old AM wideband frequencies that were designated by two colored ribbons are illegal to use. Any radio that is on the current channels is legal to use, whether it be AM, FM, or PCM(a FM modulation scheme), as long as it ith they are not illegal.s narrow band. However, some of the older receivers sold with early narrow band transmitters are wideband and not reccommended for use although they are not illegal. This issue was mentioned in the latest issue of RC Report(February) in the Radio Ramblings column.

RCFlyr sed that! d:^)

The radio "in question" is a gold box futaba with no gold sticker. It is therefore wide band. That is clearly what Paul meant. Let's all try to be helpful, rather than pick nits.

RCFlyr wrote: let me try this again!!

narrow band transmitters are wideband and are not reccommended for use,

I was ONLY talking about HIS radio, not AM in general.

re-reading Pauls earlier reply, he said (paraphrasing) "if its fm, your ok - all futaba fm's are narrow. If its am, well, get an FM module". He didnt specify why. In my rc car experience, a guy goes FM for signal clarity.

He didnt say the AM version was illegal, just that i would want an FM version instead. Frankly, i'd heard enough already to scrap the radio entirely, but thats not the point. I said: " Really? interesting. Its Am, i dont really care, until it starts glitching. " I have plenty of AM 2-ch surface radios that work fine.

I didnt say: "Really? interesting. If its illegal, i dont really care, until i get caught"

I have no intentions to break laws or just be a risk in general. Fact is, even old AM radios typically work fine - unless i suppose the bandwidth is no longer legal. Now, old servos are a different story....

To sum up, im not trying to argue that i should use an illegal radio - of course not. It simply wasnt clear that it is illegal.

PS: anybody wanna buy a 'vintage' radio cheap? LMK. MikeF

I'll need an RX too i suppose. Are the fm modules currently available? or ebay only?

Thanks for the help, MikeF

Get new electronics. You don't know how that Tx was treated. Start with a new radio setup and you will know its history. You are going to want a new Rx and servos anyway. I like Hitec and an Eclipse would be a good choice. The Flash 5X is also good, but I like six channels so I can have differential aileron throw controlled by the radio. It can be done mechanically though.

How heavy is the plane? The OS 35 may or may not be enough engine. Check all hinges to make sure something doesn't fall off the first flight.

John VB

bigger and faster

so this wasnt her

anodized case, but

Scrap the radio (any

monokote alone for

RCFlyr wrote. Sorry if i got anyone's dander up. Maybe I missed something here, but the statement that I read was somewhat broadbanded and I interpeted it to mean any AM radio. However, I believe that any AM radio that was manufactured with the current fifty 72Mhz channels is legal as far as the FCC is concerned. There were some that did not quite meet the AMA,s standards and were given a silver sticker instead of a gold one. Am I wrong here?

>

Not wrong.

Although obsolete, silver stickers were affixed to transmitters which met the pre-1991 wide band frequency tolerances and thus were legal for use until the end of the five-year narrow band phase-in period which ended in 1998, irrespective of modulation scheme (AM or FM).

For example, all Futaba FM systems met the narrow band standard whereas many of the AM (older) systems only met the wide band standard. My two FP-TK 7-channel gold face AM transmitters were factory-converted to FM and were subsequently issued a gold sticker when tested at the one-and-only RCMA show here in hotLanta in 1990.

Futaba still produce 2 and 3 channel AM systems which comply with current narrow band frequency tolerances.

See the FAQ :

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Fred McClellan The House Of Balsa Dust
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