alasdair

Mike,
You are right to point out it has to be a one piece flying Canard.
I suppose a standard Reaper could be converted to an all flying foreplane if required.
Anyone done that??

BaldEagel

Yes, have a look at the top of page 5.

Mike

siddus74

Al,

I did indeed see the lochstar, tbh the first 3 or 4 minutes of flight was so bizzar I thought the plane was out of control! . . . it landed so so slow. Maybe we can discuss it at the next meet . . .

What is your choice of power supply when using Spekrum in a jet plane such as the Reaper and the Boomerang, what do you think of my choice of servos in the Boomerang?

Best regards and thanks for any advice.

Scott.

BaldEagel

JetCat's instructions are quite specific on this issue, if your Kero start turbine does not start first time you must tip the airframe up on its nose whilst holding a rag or towel at the starter motor end to get rid of the excess fuel that will have acumalated in the compressor, tipping the airframe up on its tail will not get rid of the excess fuel as the vanes from the compressor will prevent the fuel passing through into the combustion chamber and out of the efflux.

That's why first start of the day on my Elan I do without the tailplane attached, but then again I have never had a failed start, hence no hot start's either.

MIke

alasdair

Don't you get fuel all over your starter motor?
I agree it pays to be extra careful when using kerostart. That hasn't put me off trying it.

BaldEagel

Not as careful as you should be when using Propane, highly volitile and is heavier than air so it lays on the ground in any hollows just waiting for a discarded cig or match.

My Kero start JetCat's have been 100% succesful without any problems whatsoever, now days I don't use a UAT either IMO with proper plumbing and an air tight system its not needed and so far 60 flights have proved to me that it still works without one.

Mike

alasdair

Scott,
For calculating servo torque required I have a few methods. I drew a nomogram many years ago based on Carl Risteen's article in M.A.N. and I also have a program from it.

A great servo calculator that runs as an Excel file (written by Craig Tenney) can be downloaded from
http://www.geistware.com/rcmodeling/calculators.htm
[link]http://www.geistware.com/rcmodeling/calculators.htm[/link]

Just measure the model surfaces and estimate the speed.
For a Boomerang the speed will be around 100 mph and control deflections are modest.
For flap make the speed 50 mph and deflection 80 degrees. (20 for takeoff)

I can't remember what servos I used in the Boomerang. Certainly not digital, may have been high torque Hitec 625 or TP 5010, I just fit and forget, and sold it 130 flights later.

For the Spektrum radio (fitted in my JayTee) I started with a 5 cell AA high capacity battery but soon switched to a 5 cell 1400 mAh high current battery (I think the cells are 2/3 subC or similar) when I learned about 'brownout'. The high capacity NiMH AA cells have a high internal resistance and the voltage sags under load. With "quickconnect" receiver and a fade counter if possible it is not a problem.

siddus74

Al,

Thanks for the advice on servos etc, so you are not running any battery backers and or any voltage regulators etc?

Wow, I thought I had to run all these to be compliant . . .

Scott.

alasdair

Scott,
On my Boomerang I used a pair of 5 cell nicads through a backer and thence into my JR Rx. The backer charges a 1 volt admin fee which reduces the voltage to a level acceptable to JR equipment.
When I built the Rookie I transferred the whole setup.

In the O/D JayTee (photo left) I decided to go KISS and used Spektrum with a single 5 cell battery. It is under 7 kg and I'm aware of no UK regulations to the contrary.

Incidentally Scott, the Boomerang had a UAT but the Rookie and JayTee use a pleated paper fuel pickup plumbed straight to the pump.

BaldEagel

There are not regulations in the Uk re battery backers, as I said earlier I just use two 2 cell A123's straight into the Rx and have been for all my flights with the Elan, but I am fitting an Orbit PowerJack so that I can use the dual battery connections via the MPX sockets on it.

Mike

siddus74

Choices choices,

So Al, one of your jets is running a battery backed 6v drive 4.8v supply to a 35 mhz rx? what battery backer is that? (Loving the 1volt comment v funny) My reaper is on JR 35 mhz still and has high spec JR digi's that can only be satisfied on 4.8v []:-(. Your other Jet other is on a 6v supplied AR7000 spectrum RX with no backer are you not concerned? . . .
My reaper has a Uat with a bag in it? And the boomer has a cheap smaller header tank with a star shaped paper filter, is this what you meant Al? Apparently they both stop air bubbles and flames outs . .


Mike, those photos you suggested you would post? I am interest in your choosen setup, the 6.8 volt nominal - can you explain that concept and how it works out when using 6volt capable Servos and presumably a 2.4 RX with no regulator (spectrum or futaba I presume)

The wealth of knowledge here is fantastic . . . thanks in advance . . .

BaldEagel

siddus

Will post the photo's tomorrow for you, If you think about a 6volt five cell Nimah they come off the charger at about 7.2volts and no one thinks twice about putting them straight into a Rx and servo's, so using a two cell 3.3 volt A123 will give you 6.6volts nominal or about 7 volts straight off the charger, this will quickly drop down to the 6.6volts and stay at that voltage for approximatly 2000 of its 2300Mah capacity so will not cause a problem with most Futaba equipement and some Spektrum, but will cause a problem with a lot of JR servo's.

It seems that every since the advent of Spektrum brown outs JR are only now starting to bring out servo's that can perform with certainty at 6volts, this obviously is to get as far away from the brown out voltage as they can, I mean they even call their new super dooper Rx "Power Safe" because it has two large gauge wire leads for battery connections??????????????????????, they still havn't cured the Brown out issue, just made the Rx's switch back on quicker, this is still IMO not a cure for what is a design fault, the cost of a differnt MosFet to not switch off at the voltage close to the nominal voltage of the pack's they supply with the Spektrum sets is not what I call good customer relations, they still only supply a four cell Nimh with the sets, that's a 4.8pack.

For the record I fly Spektrum in my most disposable airframes, not my jets.

Spektrum is still 10,000% better than Graupner IFS or XPS ever was.

Mike

BaldEagel

Two photo's one showing the installation without the UAT and one with, also shows the two Kodiak switches which plug straight into the Rx, the two A123's are in the back under the tank no need to remove to charge them.

Mike

EDIT: forgot I have refined the instalation a bit more since taking the photo, removed a connection on the Tygon and moved the piping a bit to make it neater.

siddus74

Mike,

Thanks for picture, sweet install - what model is that?

What servo's are you running in conjunction with te A123's? Just had a quick scout on the net they are not cheap are they!

Scott.

siddus74

Mike,

Just been reading about the fromeco wolverine swithces, sounds like just the ticket, it has the sharing circuitry in the switch . . . [link=http://www.fromeco.org/Products/04FRCWO-431s/Default.aspx]Fromemco Wolverine[/link]

I figure of those with a couple of the newer Eneloop 6v batteries and the 6v capable servos and I should be set . . . what do you think?

Any idea where to get these in the UK? (Wolverine 2 Deans in 1 Deans out Silver)

Scott.

BaldEagel

Siddus

Thanks for the compliment, the Jet is a Boomerang Elan with a JetCat 120SX in it.

I am running Metal geared Digital Hitec all around, been using them for years without any problems.

The Wolvernne souds just right if you don't have enough sockets on the Rx for two batteries in, Go for it.

I did see earlier someone is now stocking the Fromeco stuff, will have to dig back and find out for you.

Mike

BaldEagel

You can get A123's much cheaper on e-bay, look for a DeWalt 28 or 36volt Nano battery, they both use A123's in them.

Mike

EDIT: link to Realraptors who stock some Fromeco stuff, but don't list the switches perhaps a call to them may bring something up?

http://www.realraptors.co.uk/shop/in...index&cPath=90

siddus74

Mike,

They dont stock them but can get them but the lead tiime is about 6 - 8 weeks . . . and they did not want to comment about the prices etc . . . the other more expensive option of course is the Spektrum AR9100 . . .

Scott.

Knock

My Feedback: (2)

Wayne 22 This is my gear setup . Sierra precision on the nose ....too expensive when needs repair . Intairco wheels on the mains....dig into the grass too narrow and hard. The main gear is too low , I tried to PM this pic but file was too big .I also have a TJT 3000 in my Reaper . Where do you get your TJT 3000 serviced ?

Thanx in advance

BaldEagel

Scott

Did not know you where on Spektrum, I have no doubt you have mentioned it before, but my thoughts will be with you at this difficult time, so sorry to hear the news. LOL.

Mike

BaldEagel

Scott

Do you know anyone in the US that could buy the switch for you and send it over, could work out cheaper if it is a gift, nudge nudge wink wink, say no more squire.

Mike

siddus74

Mike,

I have since found the PowerBox Products . . . [link=http://www.powerbox-systems.com/e/powerbox_systeme/powerbox_gemini/start.php]PowerBox Systems[/link]

Looks like a plan.

BaldEagel

Siddus

As long as you do not use high end Digital servo's that Powerbox will be OK, JR8711's can pull 4.6Amps each so the limit would be the powerbox if you went that way, you would also have the problem of the possible low voltage drop out of the Spektrum Rx, you pays your monies and take's your..............etc:

Mike

Wayne22

My Feedback: (2)

Cool! I didn't know there were any other TJT powered Reapers out there!!! I have a couple of friends in Vancouver who know these engines inside out. I answered your PM about the landing gear...
Here is what happened to the stock landing gear after hitting the gopher hole on take off...

siddus74

Mike, yeah the amperage requires some thought . . . the Gemini can supply 10amps which I feel should be adequate . . my chosen servos are listed below

Futaba S3010 Elevator x1
Futaba S9202 Ailerons x2
Futaba S3001 Rudders x2
TPro S5010MG Flap x1

I dont think they wil top 10 amps do you? I may wire some thing up to tray and rest potential current draw . . . I stumbled accross some spectrum documentation that gave example of a 33% Sukhoi with 7 x JR8611s installed (that set up drew a maximum of 6.9amps) see the picture and the attachment for further details . . . quite interesting - what do you think?