RE: Power Expander or not -that's the question
 

I have 2 servo's per elevator making 4 all up, I have 4 Hitec 5995 earmarked for them,

RE: Power Expander or not -that's the question
 

Wow that seams a little dramatic. When my 8411s used to get the jitters every time I took the plane out all I would here is you cant fly that thing its not safe. But as soon as you touched the surface they would stop. Had over 400 flights with them no failures.

RE: Power Expander or not -that's the question
 

I would have used 8411's if I had 4 of them, but I only have 3 but I did have 4 5995's so they will do. I have all the servo's and matchbox's already, as well as a roll of heavy gauge servo with connectors etc.

RE: Power Expander or not -that's the question
 

Servos generally get the jitters when the gears are worn. For $20.00 or $30.00 you can replace the gears and have almost new servos.

RE: Power Expander or not -that's the question
 

Well I must admit Troybuilt has a new customer service rep which I found to be a bit lacking in professionalism. He gets everything done no problems but acts like he comes from the bronks and was cursing on the phone with me (not at me) and while it didn't bother me personally I couldnt help but thing who the heck is this guy?

At any rate. http://www.troybuiltmodels.com/ns/tb...#international read that and just order online.

Servos are $89 US, a programmer is $149US and a PE is $249... much better pricing than someone is giving you.


As for the redundancy, I don't use match boxes.. but if you power one and your receiver battery dies what happens then?


I fly IMAC as well and I still wouldn't want nearly 3 pounds of batteries in my plane :)

RE: Power Expander or not -that's the question
 

Ok, several points, would you order online from a company that wont answer emails? or thier rep talks to you like u havent a clue at all while giving you crud info?
Ok if my rx battery dies then its ouchies
as for the pricing, the prices I got were from the only hobby shop that actually answered my email query, not bad from 9 sent :eek: this goes back to 1st week December.
I have also stated I have a tight budget, and also most of my proposed set I already have on hand nib. While I may be going over kill on batteries I already have them, but will have a serious look at T.O.M's suggestions.

RE: Power Expander or not -that's the question
 

Well overall Troybuilt has a good rep... just their new customer service rep isn't very good. You can search the forums and find that out for yourself.. ordered there many times, they are one of the largest in the US.

Well to me it sounds like you are throwing batteries in there for no point then, sure the seiko needs a battery... but the other you don't need 3 A123s in there, if you want to power your matchboxes then get batteries with multiple leads off of them and run a lead to the matchbox, dont waste a battery, Put 2 on your receiver and leave it at that, then atleast you have some redundancy.

RE: Power Expander or not -that's the question
 

ok all said I need some help im building a bme\pau 30% extra and using 5 333 oz hd servos from tbm im using 2 flight power 2500 mah lipos through 2 switches and 2 regulators run into the reciver 2 complete redundant systems my reciver is a 2.4 fast now i belive I need to isolate the two regulators. corect? and if so how do i know what size diodes to use i have seen the batery isolation units but they run one bat at a time I want to run both so I increase my draw to 6 amp and also have total redundincy. please help

RE: Power Expander or not -that's the question
 

Just plug the power leads from the regulators into the receiver and go fly.

RE: Power Expander or not -that's the question
 

Is it necessary to have heavy duty wires from the receiver to the Power Expander, or Servo Board?
Do these wires serve mainly as the signal wire, seeing as the power to the servos is off of the main rail?
These may be stupid questions, but I wasn't sure how these devices actually work.

Greg

RE: Power Expander or not -that's the question
 

Today I called TBM and Aeroworks about running a power expander on a 100cc airframe. They said it was unnecessary. I told them the servos I was going to use, and receiver, a JR 921 2.4ghz that's going into my 106" extra 300. Mark at aeroworks said he doesn't run a power expander in any of his personal planes and told me not to waste my money. Also the guy at TBM said He did a test with a power expander. He flew his 100cc plane with the expander and then without. He said he couldn't tell a difference with or with out. And he said he put his plane threw the ringer no flying around in circles just to prove that it would work. I'm gonna go with out.:D

RE: Power Expander or not -that's the question
 

He wouldn't be able to tell the differance untill his servos draw down so much power that they themselves loose power.by that time he is in the ground anyhow.

RE: Power Expander or not -that's the question
 

his servos draw down so much power that they themselves loose power?
What?
Mark at Aerowoks is the guy who tests there new aircraft. He knows. Also he sells 35% aircraft, he wouldn't give me bad info that would cause a crash. Unless he likes replacing airframes.

RE: Power Expander or not -that's the question
 

AS your battries draw down the voltage goes down.. this effects your servo power just look at what ever servo's you are going to use and see the differance at 4.8 volts to 6 volts. It may not matter to the guy you talk to. I have a QQ Python with 7 high power servos... they recommend a Powerbox or something like it...go figure both your plane and mine are 100cc type aircraft...one manufacture says forget it there not worth the cost, the other says go with it to ensure safty of your plane and everyone else around??????

I have always used some sort of devise... but that is just me. You need to do what makes you feel O.K. And speaking of selling airframes... that is what they sell don't they???? It would be to their benifit to sell more product don't you think??????? especially since you can't blame a stuffed airframe on them no matter what happens to it or how it happens. Anybody will be happy to take more of your money if they can... So why not have some saftey built in?? Two switches and two battries are only good if only one of them fails.....but what happens if they fail in such a way that they fry your recevier??? that is sure death to the airframe. The PowerBox I use isolates not only the two battries and regulets the voltage but it also prevents a receiver from frying due to a bad battery.
This is just my thought??? buy as much safety as you can affords...Powerboxes are not cheap but the cost way less than a new airframe and engine....... this I know for a fact. don't ask me how I know this.

Whatever road you choose... have a great time in this hobby.it is a BLAST!!!

Here is food for thought... Some people question the need for an optical ignition kill switch?? Why have one if you can kill the engine by flipping off your switches or using a servo controlled choke??? Think about this. if you receiver goes dead the servo thing won't work anyway and you cannot reach your switches if the plane is more than a arm lenght away from you. But an optical ignition kill runs off the recevier power.if the receiver goes dead then the optical switch goes dead as well, thus your engine shuts down... this won't save your plane from some damage but it won't go some where or into someone with that fan spinning at full PM...SAFETY again

RE: Power Expander or not -that's the question
 

Paranoia, Sells a lot of product. Check out page 7 of this instruction manual. This is a 33% airframe but it is very close in weight and number of servos.

http://www.horizonhobby.com/ProdInfo...structions.pdf

RE: Power Expander or not -that's the question
 

I flew QB260 35% over 300 flights no power expander all 3D no problems.

RE: Power Expander or not -that's the question
 

I think the main point here is that YES you CAN fly a 35% plane without a power expander. We have been doing it for years. I have been out of flying the big birds for a few years and never had power expanders and the redundant power systems etc available when I was flying them. That being said, I am in the process of either picking up a used plane, or building a new one to fly next year, and it WILL have a power expander. To me, spending an extra $200 is an insurance policy I will take EVERY time on a $5000-$6000 bird. Just my 2 cents!

Todd

RE: Power Expander or not -that's the question
 

That's great to hear. I plan on the same kind of 300 flight setup.

RE: Power Expander or not -that's the question
 

Golfguy, Have you talked to anyone who has flown 35% planes without the power expander. Safety is not a good reason to go with a power expander for me, because the power expander is just another piece of electronics to fail. KISS comes to mind. Keep It Simple Stupid.

RE: Power Expander or not -that's the question
 

Paul, if you re-read what I wrote, I said that I FLEW 35% planes without the power expander, and yes, it worked fine, BUT until I read that a plane has been lost because a power expander failed (I haven't seen this, has anybody else??), I will go on the assumption that it is a good insurance policy, and DO plan on using one.

RE: Power Expander or not -that's the question
 

I have been doing quite a lot of reading on here and other sites looking at reliabilty issues of various components of electronic systems for giant scale planes. It seems to me that power expanders and the jr matchboxes are very reliable with few if any failures. It seems that most failures are from regulators, switches and batteries, much food for thought

RE: Power Expander or not -that's the question
 

$5,000.00 or $6,000.00?

You can do a Wild Hare 35% Edge, Extra 260, or 40% Giles for a shade under $2,100.00. That includes the engine, servos, propeller, hardware, spinner, and a few other odds and ends. [link]http://www.wildharerc.com[/link]

I currently have four 35% planes, and two 28% planes. There have been a few more. None use power expanders. None ever have. I will likely use one in my 46% Ultimate simply because there's 11 servos going in it. I'll need the plugs. Power itself will not be a problem with dual 2,500 mAh A 123 batteries.

I've never had any problems, or any doubts.

RE: Power Expander or not -that's the question
 

Did you guys check out the graph on that JR 922 manual page 7? It shows the amp draw on a typical flight.

RE: Power Expander or not -that's the question
 

$2,100???? Wow, I know my estimate was definately on the high side for a 35% bird, but I can't imagine setting one up for that. I mean I know there are less expensive alternatives out there brand name wise, but I will always stick with the big name engines ($1500 alone there with a decent set of cannisters), I'm thinking I will need more than $600 for the airframe, servos, receiver, batteries, switches, prop, hardware.....

RE: Power Expander or not -that's the question
 

I did also read the blurb, a peak of 17+ amps @ 7.4v? thats scary[X(] thats asking for burn out somewhere