Brian Taylor 81" Mosquito

[Frank Day]

Just in the process of gathering materials for the above, short kit curtesy of ebay and Sariks for additional wood packs and molded items.

 

i've run into an issue with landing gear. I've previously been in contact with John at Unitracts for some TN Typhoon landing gear but his phone just rings out now. Does anyone know if he is still trading and if so a way of contacting him.

 

Alternatively does anyone have a set for sale or have the ability to produce one or know of a suitable alternative. I have briefly looked at the Seagull 80" Mossie but cant find any spec for them.

 

Frank

Edited April 19, 2021 by Frank Day

[Graham Davies 3]

Hi Frank,

It might be worth looking at this thread:

 

Richard Wills has created a really nice, simple option.

 

Graham

[Piers Acland]

Hi Frank,

I'm part way through the BT Mossie.  The U/C was a real struggle.  Like you I tried Unitracts but without success.  Ended up replicating the same design by following PeterF's build (he used Unitracts) - search for “brian taylor mosquito retrospective build log” on Google.  A retired engineer up in Scotland called Ken King made some of the components for me - he did a really fantastic job.  However you might be better off looking into the Richard Wills' approach as per the previous thread posted by Graham Davies - could be quicker, cheaper and lighter.

Good luck!

Piers

  

[Frank Day]

Hi,

I  looked at  PeterF's and have saved a copy for later use. Bit of a concern about the way the retracts "flick" it appears that they are balking before pressure moves the "down lock" although I may be wrong.

 

I looked at the other suggestion as well, all are in the mix, I'll probably have this sorted one way or the other before i get the glue out.

 

[Frank Day]

Its taken a few years of actual looking but has been on the list for many years. I finally bought a complete, minus engines 81" BT Mosquito complete with the scale main landing gear. Going to need a go over and motors probably electric and probably a refinish at some point.

 

Looks like my still boxed Black Horse Mossie is going to need a new home if anyone is looking

[Paul De Tourtoulon]

Oh come on a couple of 4 stroke Lasers or Saito's,,,,

[Frank Day]

Would love a couple of RCV 60SP's but little chance of that at a sensible price. It has been built as IC, couple of 4s would be nice but im favouring electric with a twin merlin sound set up with scale 3 blade props

[PeterF]

 

2 hours ago, Frank Day said:

Would love a couple of RCV 60SP's but little chance of that at a sensible price. It has been built as IC, couple of 4s would be nice but im favouring electric with a twin merlin sound set up with scale 3 blade props

I see one of my photos from the RC Groups thread. Mine is still flying but on electric now, I did add that to the RC Groups thread. Whilst the 2 x RCV60SP is what I started out with, they caused me no end of trouble due to the excessive vibrations that they generated, ultimately ending in a crash that broke the wing beyond repair. I rebuilt the wing with electric motors.

 

In terms of hardware changes, the thick ribs supporting the motor have been lengthened so the motors mount directly without spacers. The ESCs have been mounted on extension plates so they sit right in the prop blast coming in through the chin scoops. Battery boxes have been built into each nacelle and hatches cut into the top of the cowls.

 

I used Hyperion ZS 4025-16 320kV motors (no longer available) with 16x12 APC E props driven by 6S 4000mAh batteries through HobbyWing Platinum 80A V4 ESCs. Measurements gave 6,450rpm at 22.3V with 47.5A, so about 1050W each = 2100W. The plane now weighs 8.07kg = 17lb 12oz which is exactly the same as it weighed in IC version without fuel, so the flying characteristics should be the same. The ESCs both have 10A BECs with adjustable voltages. I have set up both to feed the Rx through Schottky diodes with one set at 6.0V and the other at 5.5V so I have some redundancy and the voltage telemetry alarm will indicate if the 6.0V one fails. UK weather is very windy at the moment so the maiden may not occur for another week or so.

 

The pull on the ground was tremendous and much more than the RCV 60SP engines which never reached much above 5,500rpm on 16x12 props. The RCV engines flew the model sedately, the motors give potentially  40% more thrust, which is why it felt so powerful on the ground. When I flew it for the first time on motors it was a much more relaxed time than with IC where I was always waiting for one engine out. I was happy to do rolls and loops now without the concern of losing power. It really does fly like a large sport plane once it is in the air.

 

Someone on my thread mentioned that they had used a 4S set up but it was quite sedate, have a look at the last few pages. My build log.

 

 

 

[Paul De Tourtoulon]

13 hours ago, Frank Day said:

Would love a couple of RCV 60SP's but little chance of that at a sensible price. It has been built as IC, couple of 4s would be nice but im favouring electric with a twin merlin sound set up with scale 3 blade props

Like a couple of sewing machines, no thanks mine overheated a lot and was unreliable, now sold,,,,,

[Frank Day]

Hi,

Mossie ownership has been a saga. I posted a few questions in the last year or so as I had acquired a short kit etc and was looking for landing gear before starting.  I had a few replies but never managed to get a number for the suggested makers. I contacted Robart who will still make a set from the  BT drawings they have, they don't advertise as they hadnt had a request in years but the quote of around £1000, yes £1k delivered to the UK inc VAT and import ransom and excluding servos etc saw my interest waiver.

 

With the prospect of a £2k build and hundreds of hours ebay beckoned and I sold it and a pair of BNIB RCV91CD motors for a nice price.  Despite some iffy reports I bought a Black Horse Mossie, motors props, scale bitz crew etc. Now also on Ebay.

 

Sariks have some nice glassfibre cowls etc and alloy spinners so once I've checked it over I'll either cry or pick up some upgrade parts. 

 

Great pictures and notes, I'll probably look at that more and pester you if thats OK.

 

Im thinking of using these or similar motors/prop advice welcome.  4258-460Kv 14-Pole (FMS/Elite) 15x8 3 blade or  5065 320kv-ish prop tbc also FMS - Eflite

 

I still have  90 & 120SP's they seem to be sensitive to the break/run in process, cross cooling when in the model and during break-in and fuel. I only use Westons Prosynth. RCV Westons have details of the ducting required

[PeterF]

I missed your post of last year which surprised me, but in retrospect, I was rather busy with other things at the end of April.

 

On the retracts you said that you thought that they may be baulking towards the end of the cycle. They slow down at the end for two reasons, the first is there is a set screw that acts as a throttle on the air flow, but as the retracts go down, with the help of gravity they only need a light pressure to go down and they appear to get ahead of the air pressure, which then catches up to lock the retracts into place. Secondly, the geometry means that the oleo legs do not move much as the last part of the control arm rotation occurs. The only issue is that the mechanical lock in the down position relies on the trailing arm from the bottom of the oleo to the top rear of the nacelle going beyond 180 degree and the hinges then have a hard stop. If you do not make sure that this can occur then you only have pneumatic force holding the wheels in the down position, which can result in the U/C folding back on landing, I have suffered from this. A poor landing that causes any twist in the retracts can result in this occurring on subsequent flights, so if you have a poor landing, check the retract line up before your next flight.

 

I have put a Turnigy SK£-5065-320kV motor through ecalc on 6S and this suggests that it may spin a bit faster than the details for my motor above, drawing a bit more power and would definitely fly the model. ECalc does not have the motors you list in its database so I chose a close match. On the 460kV motor I would have thought a 3 blade 15x8 would overload the motor, eCalc suggests that a 13x8 3 blade or a 14x8 2 blade would be better. 

 

Happy to answer any questions.

Edited April 4, 2022 by PeterF

[Frank Day]

Not sure the landing gear ref is mine,  though i was speaking to another member about the BT gear availability issues and Black Horse Mossie landing gear weakness.

 

The 4258 460kv are eflite FW190a I think the model is about 8lb auw with a 15 x 8 3 blade and a 80 or 100A esc. The 5065 320 is again Eflite from a Draco with 100a esc and spins a 4 blade prop. So guessimated they may surfice.

 

I did RC many years ago and have been back a couple of years on and off. the electric stuff although an awful lot clearer is still a source of confusion with different combos of kv on the same motor with different cell count  batteries