RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Twin & Multi Engine RC Aircraft (https://www.rcuniverse.com/forum/twin-multi-engine-rc-aircraft-192/)
-   -   DeHavilland Mosquito (https://www.rcuniverse.com/forum/twin-multi-engine-rc-aircraft-192/2007938-dehavilland-mosquito.html)

david polley 01-03-2013 01:51 PM

RE: DeHavilland Mosquito
 
ALL,

Just talked to Dave Brown from Dave Brown products and he informed me that Yes, he can make a 3 1/2 inch spinner for the Dehavilland Mosquito...Problem is that he will have to set up all of the tooling and themaster hard metalcomponants to produce aspinner to replicate the size and shape of the spinner for the CMP mosquito model....This would also include thesoftware that would have to be programmed and updated to be able to mass produce the spinner with the demand......

Tooling just to get started would run $1000.00 andthe tooling would only be for the 3 1/2 inch spinner......Tooling for other sizes would cost about the same foreach......

He did tell me that of course it is a supply and demandissue.....He suggested that I write here in this forum to find out howmany folks would be interested in the custom spinner and at this point the suggested price he toldme would be a little under $75.00 a piece,but that price could comedown if more folks really showed an interest...I suppose it is up to all of you out there to decide if Dave should start a production run on the spinner for this model and others that can use the spinner...I also suggested to Dave that the spinner he ends up making could be used on other European WWII models like the Spitfire, Lancaster, and the Hawker Hurricain, and others I am sure....

Let me know what you guys think...

David

mike early 01-03-2013 04:12 PM

RE: DeHavilland Mosquito
 
damn, they want 60 dollar shipping...

But I have found how to save another .88% with pickle1088 (10.88% savings)

cathurga 01-04-2013 08:53 AM

RE: DeHavilland Mosquito
 
Badazz...that's more like it..lol. Motor mounts will depend on the motors you choose....gonna need to do some measuring. Then select one that is mid range on those adjustables...

badazzgti03 01-04-2013 09:02 AM

RE: DeHavilland Mosquito
 
yeah measuring it is..going to get either eflite power 60s or turnigy G60s for this. as for the spinners ill be down for the brown lol!!! i need to get spinners for this anyways

cathurga 01-05-2013 12:38 AM

RE: DeHavilland Mosquito
 
badazz..... I put the numbers into ecalc with the Power60....and it is not a great result.....amp draw is pretty low, but with 13x8x3 MAS props, there is not really enough pitch speed....I got numbers like this:
33A, 600W, Pitch Speed 60Mph, Static Thrust 3.5Kg's: Eflite P60 with 6S 5000Mah pack (per motor calculation, not total for both)

I am not electrical expert, but that setup seems to be creating a lot of torque, at low amps, but it means the plane will be flying on the props, and not the wing. The flight times would be great though.....around 9mins. I worked this out on ecalc using ONE motor, and just divided the weight which I estimate to be around 6.5Kg's total, in two. I also divided the flight times by two as the second motor will be drawing off the same pack.

I have opted for the Turnigy L5055A - 400KV. It is VERY similar to the P60 but it seems to generate a little bit more revs (forum rumours say it is over 400Kv) it also seems to develop a little bit more power, albeit with slightly more amp draw. I am going to use it with cut-cown MAS 16x10x3 blades, with them I get the following results:
42A, 800W, Pitch Speed 72MPH, Static Thrust 4.5Kg's: L5055A-400KV with 6S 5000mah pack. Flight times are acceptable at 7mins of mixed flying.

The only caution on this setup is that the pitch increase gives a warning of prop stall, but that is only likely if you hammer the throttle from standstill.....This plane will require scale maneuvering on this setup, but once it is 'on step' the prop stall will not be an issue.

This plane is a NIGHTMARE to get decent power setups for....the limitation is the size of the props.....if it was big enough to handle a 14" blade....this would not be a problem.

I would 'prefer' a scale look about it, but if that is not an issue.....high KV motors (700Kv) would suit 2-bladed 11x7 props.....but that would loook a little silly in my book....That being said, I might run that sort of setup on it in order to get it set up and trimmed out properly, and then start scaling it up......

I have quite a bit of work left to go on mine....I have just built all the empennage connections, I didnt want ANY external horns/rods at the back.....it looks great now with all the hidden bits at the back. Going to paint some invasion stripes today :-)

EDIT: I started a thread on RCG a little while back to see if there was any valuable input from other users on this dilemma, nothing really fruitful, but might be worth a read for those considering electric....

[link=http://www.rcgroups.com/forums/showthread.php?t=1790534]RCG 13" Prop Thread[/link]

badazzgti03 01-09-2013 08:32 AM

RE: DeHavilland Mosquito
 
Awesome I appreciate the hard work on getting the info for me. So you would consider the turnigy L5055a? I was also considering instead of a 60 maybe a rimfire .46? I'm not all that informative on electric set ups as well.

Thanks again

Jonathan

kahloq 01-09-2013 09:02 AM

RE: DeHavilland Mosquito
 
I would suggest using two turnigy easymatch G60s with the 500kv. They are designed to run smaller props on 6s so u could run 12x8x3s no problem

cathurga 01-09-2013 11:16 AM

RE: DeHavilland Mosquito
 
Kahloq, yep also a good suggestion, I was considering that as well. The only thing that stopped me was the amp draw. On that setup, according to ecalc, it would be approaching 60A. I was hoping to keep the amp draw below 50.....which my setup does, the only problem is that it introduces two other variables....pitch speed and prop stall.

I am thinking of maidening it with the 13x8x3 setup as it has more raw torque but it is not going to be as quick....if it is quick enough to fly on the wing....I will stay with that ....If not, I chop down the 16x10x3's and open up another can of worms in pursuit of some speed to get her 'on the wing'.



Jonathan, I dont know how accurate my readings are, but I am going to be doing some 'real world' testing with the watt meter this weekend. My motors have arrived, and I have installed them. I am NOT impressed with the bearings they have in them....rough as guts in my opinion, I might take the time to replace them with some decent ones if they seem even SLIGHTLY bum when I bring up the revs. Where do they get these bearings? In rubbish tips or what?
The 16x10x3 props are HUGE. I can say that when they are chopped down they will look pretty scale. Nice and thick blades :-) Now I will find out my motors battle to turn them...lol..

kahloq 01-09-2013 12:30 PM

RE: DeHavilland Mosquito
 
13x8x3s will NOT fit on this plane unless you position the prop an inch forward of the front of the cowl. Another motor option is the gunfire .60 with 650kv. You can run an 11x7x3 or 12x6 or 12x8x3 on 6s. I have three of those in a vtol. Max amp draw could be 60 or so but nothing says u gotta be at full throttle all the time. Its nice to have the power when u need it.

cathurga 01-09-2013 12:46 PM

RE: DeHavilland Mosquito
 
13x8x3 fit PERFECTLY on mine, with no mods to the cowl whatsoever. Spinner backplates are 2mm away from the stock cowl, and there is a gap of about 7mm between blade and fuse.

kahloq 01-09-2013 01:42 PM

RE: DeHavilland Mosquito
 
Hmmm. Cuz on mine, there was no room for 13x8x3s. Originally was going to use electric motors.....even had them already....but when I mounted the motors, the props wouldn't fit. They scraped against the fuse. Even with the saito .91s I ended up using whichput the spinner backplate forward 3/4 inch, I had to can't the motors outward to get the 13x8s to fit and there is still only a few mm between the prop tip and fuse. This is after where the nose starts to taper inward.....so there's no way I could have gotten those props on this plane lined up closer to the cowl front and still have any motor remotely centered in the cowls. Maybe my plane was buitl funny, but they all came from the same fiberglass moulds.

badazzgti03 01-09-2013 05:33 PM

RE: DeHavilland Mosquito
 
Hey cathurga what motor mounts or stand offs are you using? Ill be pretty much using rimfire .60 for power. Let me know so I can make some purchases soon

Thanks

Jonathan

cathurga 01-10-2013 12:07 AM

RE: DeHavilland Mosquito
 
Badazz, I used some Hangar 9 mounts that I found in the LHS, I was not sure whether they would fit when I bought them, and just took a chance. They do fit, but I required two small spacers (bolts, in my case ..LOL) in order to get the clearance on the backplates. When I get home I will measure them. Be aware though, that these are not full mounts like the ones you linked to earlier, these are just standoffs that connect to the x-plate that comes with the motor. The ones I have are similar to H9 Part#HAN4046. I will measure up this evening for you.

Khaloq, this is very strange mate, so much so that I went to check my order for the props, and make sure they are 13" and not 12"....and it seems I have 13" props on it for sure....but I am going to triple check when I get home because this is FREAKING me out! :) Maybe the vendor sent me 12" units contrary to my order...
Anyway, I am still going to try and get the biggest 3-blader on that I physically can. I am certainly no scale nut-job, and my skills are nowwhere near what you guys are capable of, but I WANT big 3-bladers....lol

cathurga 01-10-2013 06:38 AM

RE: DeHavilland Mosquito
 
Yeah, defo got 13" props on there.....whew, was wondering if I was maybe talking a lot of poo....

Badazz, The mounts I have are approx 28mm long standoffs and the distance to the the motor backplate is approx 35mm INCLUDING the 'x-mount' and the spacers I have in place. Those ones you linked to looked adjustable so aim for one that has around 35mm from firewall to motor backplate.

kahloq 01-10-2013 07:53 AM

RE: DeHavilland Mosquito
 
Strange u could fit 13's but on mine I wasn't able to. I've even uploaded pics on this thread showing how little clearance I had even with the props more forward. Anyway, great u could make them work

badazzgti03 01-10-2013 01:14 PM

RE: DeHavilland Mosquito
 
Awesome thanks a lot man ill put the info to good use

cathurga 01-15-2013 12:37 AM

RE: DeHavilland Mosquito
 
I managed some progress on the weekend, but not nearly as much as I would have liked to do. The one area where I am having some problems is how to mount the batteries. I have seen a few electric conversions where people have done a 'hatch' type job by opening the canopy and inserting the batteries into a 'chute' that goes into the nose. In the one specific case, the builder has used a pair of 6S 2500Mah batteries, but has still had to add significant weight and Rx batteries into the nose of the plane.
I would like to avoid adding any additional weight into the model, and I am using a single 6S 5000Mah pack, and the sheer size of it does not really allow me to use the canopy as an entrance. I also want to avoid connecting too many different cables when assembling at the field. With the way that I have it now, there are two small Rx packs built into the wing section that power a generic powerbox. They are only small 3S 1000Mah packs,but between the two of them, they have anough power for two or three flights. The are failover packs, so in the event of one failing, the other is still providing power. All the Rx equipment is mounted in the 'bomb bay' through holes I cut in the upper wing section. I did not cut through any spars, so everything is structurally sound...

Soooo, this is where my problem exists. I have cut a hole in the nose secion that allows the battery to pass into the nose section, but once it is in there, it is free to 'roam', not ideal. I need a way to secure it. I had thought about a removable tray but due to space limitations, it might prove difficult. I have resigned myself to the fact that I will need to build a cage in the nose, that the battery can slide into. I can cut into the firewall behind the nose (where the front blind nut mount is) but although it is not structural, I dont want to weaken that area at all. The 'cage' will be longer than the battery so that I can do some adjustment fore and aft to gain CG.
I decided to manufacture a plywood base, with balsa struts up to the 'roof' which again will be plywood with some material removed to allow the wires to connect. When I get the CG right, I will make a stopper and a latch to secure the battery in place.
The nose cone will be attached to the front with a hinge and a set of magnets so that I can flip it open to change batteries.

This is my plan, but I could alway do with some inspiration from the expert builders here. I will try to take some pics this evening to demonstrate what I am doing.

Regards

badazzgti03 01-15-2013 10:18 AM

RE: DeHavilland Mosquito
 
Hey Cathurga,
when i bought the wing off a fellow member on here he cut panels right behind the firewalls of the motor mounts for the batteries...check out in the pic. hope this gives you in idea. Batteries are in place of the fuel tanks.

http://i242.photobucket.com/albums/f...ps5d29ebd5.jpg

havnfun 01-15-2013 03:33 PM

RE: DeHavilland Mosquito
 
Pete-Thanks for the great link; what an aircraft.
Havnfun

kahloq 01-15-2013 03:42 PM

RE: DeHavilland Mosquito
 
Hope you can get it balanced putting the batteries behind the motor firewalls. On mine, with two (heavier then electric) saito .91s and aluminum spinners, I still had to add two 6v 2300mah rx packs in front of the nose covered by the clear plastic nose "glass". As a result, I painted the nose piece and put guns in it to hide the rx packs. Remember, the CG listed in the manaul is wrong and it needs to be 85mm from the leading edge of the wing(against the fuse).


cathurga 01-16-2013 05:31 AM

RE: DeHavilland Mosquito
 
Badazz, wont work on mine unfortunately, these big packs wont fit into the nacelles, and as mentioned by kahloq, need mucho weight up front....

badazzgti03 01-16-2013 06:21 AM

RE: DeHavilland Mosquito
 
ok well it was just an idea....
but anyways I got the rimfire .60s in yesterday with the GP medium size mounts..to a great disappointment the mounts wont work..grrrr...the motors are too big for them and the larger mount is to big to fit the nacelles. So now i'm stuck in a big fukkin rut! what do I do about the motor mounts?? i'm clueless at this point. I really don't want to have to make custom mounts for this.

cathurga 01-16-2013 07:16 AM

RE: DeHavilland Mosquito
 
Badazz, thanks for the idea anyway, no matter how pathetic it was, it was still an idea...LOLOLOL....jk, (I have an awful sense of humour that most people actually find offensive :-) .....please dont!

Not good to hear about the mounts, and to provide you some inspiration to continue.....this is how I did it.

http://img.photobucket.com/albums/v2...pse5fe6f71.jpg

cathurga 01-16-2013 07:26 AM

RE: DeHavilland Mosquito
 
While I am in picture taking mode, here are some pics of the battery idea I came up with:
http://img.photobucket.com/albums/v2...ps921b7d55.jpg
Raw Tray, just balsa, ply and epoxy....

http://img.photobucket.com/albums/v2...psf3955447.jpg
Another view

http://img.photobucket.com/albums/v2...ps0b1dd723.jpg
More...

http://img.photobucket.com/albums/v2...ps3a665b3b.jpg
Installing into nose...

http://img.photobucket.com/albums/v2...ps3f9d17fd.jpg
A bit wonky, but it will lie flat when installed.....

http://img.photobucket.com/albums/v2...ps8d3cccd3.jpg
LIPO installed. I have a cunning plan for a latch, but I need to find out where the battery will sit. I am guessing as far forward as I can get it.....

badazzgti03 01-16-2013 07:27 AM

RE: DeHavilland Mosquito
 
its all good man..So you basically used stand offs..is that something that is made or bought? if so where can i get them?


All times are GMT -8. The time now is 03:53 PM.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.