Hi All!

I'm keen to do another multi-engine job, and have noticed what seems to be a nice size and very scale looking plan and ABS pack (canopies, cowls, dummy radial engines, scale wheel hubs and wing tips) on offer from Q&EFI's plans service. It spans 93" at a scale of 1:7.5 .

I would like to hear from anybody who's built the model, or have any comments or suggestions. AUW is unknown, but specified power is 2x 700 size geared motors, cell count unknown. I'd probably use brushless motors and round cells- not much nose section on a Beau so I presume a little "ballast" might come in handy!

Thanks in advance

Marius

Hi Marius

This is the setup that the designer John Ranson used in his prototype:

Motors: Speed 700 14T
Props: 15x10 APC
Batteries: 2x14 cells
Gearbox: 3.7:1
RPM: 4900
AUW: 16lb
Current: 25A
Thrust: 2550g
Wing load: 32oz/ sq. ft.
Speed: 43mph
Watts/lb: 47

Some of these figures are from motocalc (speed etc) but others are as measured.
I got this info in a spreadsheet from John when I bought one of his other models.
Good choice of subject!!

Alan

Thanks for the info!

Yes, I think this is an infrequently modelled design. The wing loading and AUW look pretty high to me, and W/lb figure seems to be a bit on the marginal side with that setup. Do you have any idea what the performance and handling were like?

Cheers

Marius

PS:

Check this out: http://www.clubhyper.com/reference/b...ferecebg_1.htm
http://www.compass.dircon.co.uk/Beaufighter.htm

Hi Marius

I think some of those Beaufighter parts in Australia have been moved to Duxford here in England. I'm sure I saw them there a few years ago.

I haven't seen John's Beau fly, but I can tell you that the model is still in perfect condition and flown regularly, so it must not have any bad habits :-)

The watts/lb figure is a good indication of the performance you can expect and the 47watts/lb figure for this model will give typical WW2 fighter/bomber performance.
This model also carries a droppable torpedo which isn't small, so power is not marginal!

A more modern power plant would be 2x ten cells and a pair of AXI 2820s or so..probably propped down a bit to allow less current...something like 9x9 sort of props. Three blader varios mebbe?

he has 28 cells in all in that thing..no wonder it was heavy.

Otherwise a couple of belt drives on an inrunner would allow 15" props..

Alan: That does it- I gone ordered the dang thing!! You may be right about the w/lb issue- our 12ft Nijhuis Lanc flew pretty respectably on just about 60W/lb.

Vintage: I've a pair of those available, as well as a pair of Mega 22/30/3's and some MEC superboxes with gears for 2:1 to 3.2:1 ratios, so these are pretty versatile. AXI 28/26/10's should do okay too.
Any more suggestions would be appreciated. I can feel the juices stirring already!

Marius

Vintage

I bought John's Halifax from him in December. He originally flew it with 2 packs of 8 x 2400 NiCds in parallel. AUW was 6lb 9oz. I have put in a single pack of 8 x 3700 NIMh in and reduced the AUW to 5lb 4oz. it just shows there is no single right way.

The figures I quoted for the Beau' were the original setup from year 2000 and I'm sure that there are many and better ways to do it now. At least Marius knows a proven starting point...

One of our club members has the Beaufighter from the Traplet plan (70" I think).
It uses 2820/12s on 3S LiPos. It has flown and has loads of power available.



rather poor shot of the landing approach

R101

Thanks for the pics....

Just goes to show nothing beats a naked model

Marius

Ivan Pettigrew does a Beau and a Mossie plan ..the beau is 1/10n scale so that's 73"....sounds like you've done your deal but take a look at his set up ....he may have revised it recently.

Good choice though an aircraft with attitude especially the anti shipping versions.

Do you by any chance have a link or an email address?

Marius

I'd imagine that 2x2820/10s wouldn't be anywhere near enough power for this particular model. IIRC from the magazine article John Ransom used two Graupner sp700Neodym with the speedgear 3.7:1 boxes on 14 cells per motor. One of those is enough to fly a 6 -7lb model easily on it's own, so two would fly the Beaufighter, as demonstrated by John's setup. Of course using Lipos you would lose a substantial part of that weight.

However it's still a big model and for a brushless setup I think you should be looking at something a bit larger than a pair of the 2820/10s, which are really ideal for models weighing in at 3-4lbs, making a pair of them more suitable for something in the 8-10lb AUW range. Even with Lipos you aren't likely to lose over six pounds in model weight from the prototype.

Originally Posted by mariuslj

Do you by any chance have a link or an email address?

Hi if you were after Ivan this is his site and his E mails on it.
http://www.geocities.com/ivansplans/
great vids are at http://www.dvflighttech.com/ Mossie in flight and also Bristol frieghter.

Thanks for the information.

Should receive the plans and parts in two weeks- will try to post some pictures.

Brian I suspect the geared Mega motors will be used, or otherwise get another AXI 4120 and use those ( MEGA 22/30/3 at 2.5:1 gives same kv as AXI 4120/18). I'm limited to 3s 3700 mAh lipos- will probably need 5s or 6s if the lipo route is taken. Probably best if "mommy" is kept in the dark as far as the budget for this one is concerned!!

Marius