Predator Wren Question

[Matt Jenner]

I normally fly Futaba,

I wanted to know what Radio gear you all use,

I normally use the 9255 for cyclic
601 or 611 with the 9256..

I will not be stick banging, but just flying fast circuits 8's etc, maybe when i get the courage i will do a loop and roll...

Matt

[DDragon]

Hi Matt,
mines not finished yet. But I plan on using my DX7 with an AR7100 RX. I plan on using these digital servos for the cyclic: http://www.acehobby.com/ace/digital_srv.htm they are all metal and look cool. I have a Futaba 611 and servo on my 600E which I'm thinking of using. If not, I'll buy a new one. But I only plan on doing very basic, non-3D stuff.... so I could probably get away with a Futaba 411 if I had to.

This will be an expensive puppy, so I have no plans on taking chances until I can trust my thumbs.

Cheers,
Deron


BTW... I should add. I bought a second hand Predator airframe with complete (all) metal upgrades (head etc), carbon fiber upgrades, ungraded (new) clutch and bell, canopy etc for $500. I'm also going to get the Predator conversion kit from Sarah. So I'll only be using the top part of the frames.

I'm basically using ideas from various turbine/wren Helis like the Bergen. I ordered the UAT and will have dual 22oz side mounted fuel tanks.

I'm also getting the Duralite Helicopter package, #He-pkg E Li-Ion / Mn Bergen Turbine Helicopter Package Duralite package

I think that's it for now. Most of this was supposed to be my next winter project, but I got a little excited and started buying stuff already. I'm also building the turbine this summer (now) and will test run it. Then start the airframe built in the fall.

I hate spending time in the basement working on this stuff when I could be out flying. So I'll save most of the work for when the weather gets snowy.

[Matt Jenner]

I forgot to ask

I noticed that some talk about upgrades for the predator over and above what comes with MAX 90 kit,

Can someone please let me know what additional upgrades are needed, i assume one of them is Metal blade grips,

Many thanks
Matt

[bcook01]

Matt

Can you use SS yet? are you using 35 mhz ? BTW...... glad to see you....

using x9303 2.4 for the transmitter and R921 for the receiver. I prefer to stick with good analogue servos rather than digital due to power consumption and not really needed unless stick banging.

DDragon.
suggest going the 9 ch receiver for numerous reasons. works with the dx7.

1) four receivers for reliability
2) can monitor drop outs with option (flight log)........ don't leave home without it.!
3) has two power supply inputs that are isolated for redundancy.
4) cheap upgrade when you find out 7 ch just won't cut it.

Also if you go vstab, helicommand or ap2k you will find that the later 2 work much better with analogue servos. like the jr 4721 servos. these can run at 6 volts and have enough torque to overcome "stickies".

been using the CSM sl 570 and sl720 tail servos. Bit of an overkill but better than the 401. you can tame the tail with the pc interface.

pretty well the same setup for all the larger birds.

fyi

bob

[Matt Jenner]

Bob

thanks for the post, what is SS?

i am currently using Futaba FF9 super,

Matt

[bcook01]

Matt

spread spectrum....... sorry. aka 2.4 ghz.

BTW I have an JR R900S receiver on 35.000 mhz if anyone needs one.

Bob

[lperagallo]

Matt,

I run a X9303 radio with an AR7000 RX. Had a DX7 but upgraded the TX. I use the duralite battery package that has one 4300MAH LI-ION for the RX pack and a 4300MAH LI-MN for the Fadec, heavy duty Regulator and twin power feeds through a deans connector. By the way, with this battery set up I can do 6 to 7 flights no problem. I have futaba 9451 servos with a futaba 611 gyro with a 9256.

I had a futaba 401 with a 9254 that worked well. I changed it out when I couldn't hold position doing loops. It turned out is wasn't the gyro it was a swash plate timing issue I didn't know about. A little mix in the TX and the problem was gone. I guess if I knew what was going on in the loop I wouldn't have changed out the gyro because I also use a 40 in the gasser fine.

Lou

[Matt Jenner]

thanks for the info guys

what are parts back up like now for this model in the UK ?

I was reading RichieUk's post, he said that parts were difficult to obtain, is that still the case or has it got better ?

Matt

[Coolice]

Hey Matt,

Parts availability for the Predator in the UK has got much better in recent months, due to CenturyUS's relocation into a new factory combined parts production got interupted which was annoying for us reps and the general public. SLowly but steadily stocks got replenished, I cannot say whether some of the more exotic parts might still be inbound but the last time I spoke to Dean they had healthy stocks of all Predator parts.
Obviously from our perspective we dont want any of the models we sell to be lacking in parts and so CenturyUK made it a priority to get these spares in. A quick call to them or check of the web site would put your mind at ease.

As to upgrades, apart from the ones needed to stretch the Predator to Condor proportions, eg. longer boom & tube drive to swing 800mm blades all I have and suggest fitting is the Metal Elevator A arm upgrade : http://www.centuryuk.com/Products/Upgrades/Predator?pos=46

This is one area of the model which feels heavy loads as it is the swash anti-rotation unit and elevator control arm, for the £26.99 it costs it is good insurance to ensure safety as the plastic stock item could be considered the only weak link in the control chain.

There are other upgrades but I am not running anymore than the above arm, not even the metal blade grips/head upgrade.

Ian

[Matt Jenner]

hi Ian

nice to speak to you,

I am gonna look at a predator max 90 airframe in an hour or so,
what do i need apart from the Wren turbine conversion, do convert it to turbine...

I will be swinging MAH 810 blades,

i take note of the A frame part - i have orderd that,
what else do i need,

Many thanks

Matt

[Coolice]

Hello Matey,

Ah cool, you may have an airframe soon then.

Ideally I'd suggest dropping the gear ratio as well to 9.3:1, from memory I am using the 93T main gear and 10T pinion/clutch bell.

Main gear : http://www.centuryuk.com/Products/Helicopters+Spares/Predator+Spares?pos=16

Pinion/Clutch : http://www.centuryuk.com/Products/Helicopters+Spares/Predator+Spares?pos=99

Ross is flying the stock ratio and appears to be getting on well so see how you feel, the main gear is reasonably priced but the pinion/clutch bell is not exactly cheap.

While I was at WREN's and in the early stages of converting to 800mm mains is was felt that by allowing the turbine rev higher it's throttle response would be better, especially in view of the fact I was going to have to run it slower anyway to compensate for the longer blades. This was derived from a conversation with Mike and the use of a calculator to calculate turbine ~ gearbox RPM's etc.
In flight all you will need is a maximum of 1600~1650 for aero's and a little less for hovering and at this sort of RPM the model is happy with this length of blade and has shown no signs of fatigue/stress.
Ross's experiments with 850mm+ mains proves there is ample strength in the stock predator rotor head & grips.

Other upgrades, one you may like to consider but I am not using it is the tail drive speed up gears. Again with running a slower main rotor speed the tail rotor slows down accordingly and so power is lost, if you like a powerful tail then perhaps consider these as well.

If I could grab the MW44 conversion for mine then we could do a parts swap as I'd revert to the 90 gear ratio your models probably got and you'd need mine I have here, along with boom and torque tube................. Sara got a spare 44? ;-)

Oh, by the way I think I've found what was giving mine grief, the gearbox oil seal gave up the ghost Sunday at the MKHeli fly-in. Que lots of white smoke and a very hot gearbox.
Accounts for the reduction in head speed I was seeing at Charmouth. Calling Sara again later today.
.

[Matt Jenner]

there is someone selling the MW44,

What size blades are you flying with then ? 710's ?

Matt

[DDragon]

I forgot to ask

I noticed that some talk about upgrades for the predator over and above what comes with MAX 90 kit,

Can someone please let me know what additional upgrades are needed, i assume one of them is Metal blade grips,

Many thanks
Matt

I don't know if they are needed. I just like the extra "bling"

[DDragon]

Matt

Can you use SS yet? are you using 35 mhz ? BTW...... glad to see you....

using x9303 2.4 for the transmitter and R921 for the receiver. I prefer to stick with good analogue servos rather than digital due to power consumption and not really needed unless stick banging.

DDragon.
suggest going the 9 ch receiver for numerous reasons. works with the dx7.

1) four receivers for reliability
2) can monitor drop outs with option (flight log)........ don't leave home without it.!
3) has two power supply inputs that are isolated for redundancy.
4) cheap upgrade when you find out 7 ch just won't cut it.

Also if you go vstab, helicommand or ap2k you will find that the later 2 work much better with analogue servos. like the jr 4721 servos. these can run at 6 volts and have enough torque to overcome "stickies".

been using the CSM sl 570 and sl720 tail servos. Bit of an overkill but better than the 401. you can tame the tail with the pc interface.

pretty well the same setup for all the larger birds.

fyi

bob

Hi Bob, I didn't know you could use a 9 ch with the DX7... that's a good idea! Thanks. I'll do that!

[Coolice]

there is someone selling the MW44,

What size blades are you flying with then ? 710's ?

Matt


Hey Matt,

Nah not yet matey, still a few months off atleast with the MW44 but it is the one I am chomping at the bit for as it will be lighter and more nimble. Read that last statement as 3D'able ;-)
Also I've done my job with the MW54 in the early days, it's proven to be a winner and many fliers now use this engine in their models. It's time for me to start demo'ing the next wave of hardware.

I am flying NHP 800's on my machine, there is other blades out there and possibly even better flying blades but for their cost you cannot complain and the performance is awesome!
Auto's are a pleasure to do with the 800's to, on 720's (stock 90 size) it was very limited. Ok chuckability has been sacrificed with the longer blades but the model feels like a well guided locomotive in the air with a bite if some 3D is thrown in.
.

[Matt Jenner]

Hi Ian
Sorry the turbine i saw was just Mw44 turbine no second stage, so i guess it is for planks,,

Matt


ps : on the main shaft of the pred 90 max, which way does the thrust race go ? is it wider ring to the bottom of shaft or towards the head ?

Also i have found on this second hand machine the special washer is missing, can it be bought seperatly or does it have to be bought as a complete set ?

Many thanks

Matt

[Coolice]

Hey,

Well Dave Owens/Roger Hamilton are already flying a 44 equipped Cuatro to good effect and Lucien (WREN's turbo-prop guy) and his mate are testing the MW44 in a Hensleit I think. Over here though it's still a few months off.

The thrust race, like the ones in the head the smaller diameter washer goes on the outside edge as it is the one which normally rotates with the shaft it is on. The simple answer is the smaller internal diameter thrust washer goes towards the bottom of the shaft, resting against the locking collar.

The special washer is the small ring which sits between the upper thrust washer and the lower main shaft bearing isn't it? You know what I dont know if it's a seperate item or not................... ah ha, here it is I think : http://www.centuryuk.com/Products/Helicopters+Spares/Predator+Spares?pos=114 can be brought seperate.
.

[Matt Jenner]

YEAH thanks for the shim part number, unfortunatly there is no stock,

where as the complete set which is £34.99 can be brought, does anyone have a spare i can buy off them, all i need is the shim/special washer

[lperagallo]

Matt,

I agree with Ian that with 810 mains you only need 1,450 in normal mode for hovering and circuits while 1,650 is fine for most aerobatics. At 1,650 you have quite a bit of bite and you can throw it around pretty good. I'm not sure of the gear ratio I'm running, but I know I max out the turbine at 135,000 and I don't think I get anywhere near that when flying.

I think that Chris told me he has never seen anything over 127,000 from his set up.

Good to hear you will be in the air soon.

Lou

[Bell Bloke]

Hi Matt, sorry I was a bit slow off the mark here, I was in Poland for a while. You will find me here mostly from now on. I will only go over 'THERE' if I absolutely have to. Mind you I'm finding the format here hard to get used to, can't find all the pretty pictures...... :-)
Here's what I use on mine Servos are Futaba S9206, Duralite regulators x2, 2100mah 7.4v flightpower packs x2, 2500mah 7.4 flightpower packs x2 and 3 Sparten volt meters. That should get you going. This is the gear that Will and I have done lots of hours on with no problems so we are very confident with it. I know the servos are not the latest gear, but there is a reason for that! Track Record..............
All the best Bell Bloke.
Ps. Oh the 2 sets of batteries are for twin back-up.

[Matt Jenner]

Hi Bell

it sounded like you were at a Posh gala lunch at some country club or manor, " what what what - in posh voice)

thanks for the chat, i have orderd a couple of things from Century, a shim was missing on the main shaft, so i am gonna go down to Dean and pick them up today, they were really good, they have said they will refund my postage ipaid on the card, cannot moan at that, the machine is nearly built, not bad for my second model built by myself, i am really excited at this project,
it is ahsame i keep getting messages saying i am wasting my money on a wren and even more so on predator! but i have stoodmy ground and the individuals respect that, and are helping me loacte radio gear....
i am so desperate to do a video when i am up your place of me flying this machine around do fast climb outs etc,

LIKEWISE ON THE FORMATT, i miss being able to insert photo's to my post, or i cannot find the button to do so.but this site more than makes up for being friendly and nice to be on, i actually look forward to reading the posts rather than turning on my PC and see who has picked on and started being rude.

[Sara]

Matt,

Here's how to upload photos:
When you click on " Quick Reply" you get the box to write in with two buttons underneath, one is "post Quick reply", the other is "Go Advanced". If you "Go advanced" you get the option to attach things like pics.

I agree, it's good to open up a thread and find positive things rather than negatives. I'm sorry you are receiving messages from people telling you that you are wasting money on a Wren, I really do wonder why people say that. I don't know anyone who has a Wren and isn't happy - if they aren't happy then they need to talk to us, they shouldn't bad-mouth us to other people without giving us the chance to put things right. And if these people don't have Wrens, then I don't think there is much value in their opinion. Ignore them!

Sara Parish
Wren Turbines

[Bell Bloke]

Matt if you are not over the moon with your Wren/Predator I will buy it off you!!! That is my guarantee if you set it up how I've done mine. You will not find a more reliable machine than that combo. And if you want stupid, stupid power reliably, then you can have that too. Skeeter Pilot and I have been doing that for 2 years now. So there you go now you have nothing to loose............Then you can tell them how good it is.:)

[Matt Jenner]

ha ha

you bet, i am soo looking forward to it, by end of the month i will £2200.00 in the Wren fund, been selling some stuff on Ebay, so by Sept i should be able to buy a new one directly, or i could wait to the next open day for 10% off new engines, which is £270.00 off, - which in effect is the Predator conversion kit,

Bell as i will be setting up with you, it will be the same set up and the same radio gear etc, so i know i am gonna be really happy...

One question i have,

i heard there was 2 predator conversions, a Dave owens and one other one, i assume it is the Dave owens one i need to go for.
Matt

[Sara]

There's only one Predator conversion - done by Terry Lee of Wren, and available from us. David Owens does a conversion for the Cuatro.

Sara Parish
Wren Turbines