BaldEagel

Mejzlik have just started making electric props, if the IC versions are anything to go by they will be top quality, I don't know the sizes available in your area, suggest you do a google search.

Mike

BaldEagel

Ok guys what do you think? do I put the front former on at an angle to try and mitigate the side thrust? or do I put it all on nice and straight and keep the spinner in the middle and put a rudder too throttle mix in to compensate?

I have done the mix solution before and you can get it very accurate, in fact more than putting side thrust on the bulkhead, its also easier to modify if needs be, when you change prop or C of G. I think I have just answered my own question, but any thoughts would be appreciated.

Mike

BaldEagel

Anyone?

Mike

BaldEagel

Not much interest here, anyway the rear bulkhead and horizontal support are now fitted I have placed the rest in position to get an estimate of the final C of G, I am still not convinced on the motor angle and will probably go with a straight firewall and mix the rudder and elevator to compensate, it will just look better.

Mike

Dave Wilshere

I've been flying a 2 x 2 Extra with an AXi 5330/18 for 2 1/2 years.
It has 6000 prolite TP cells 10s and a Graupner 20 x 10 G Sonic prop.
This prop hangs at mid stick and pulls well out of the hang. Flight times are 10 minutes, with mixed 3-D and 11 minutes IMAC style.

I use a ACRO 90 Jeti controller and it hardly gets warm.
I'm using the new Spin 99 in my Spark EDF and it works well, but is more sensitive to temperature-only at higher current draws.

The 2 x 2 is quite a bit lighter than the 2.1, though the fuselage is the same. the wings and tail are heavier due to more cloth giving a tough surface that does not mark as easily.

Dave W

BaldEagel

Dave

Thanks for the information its usefull to know of other configerations.

I thought the 2.1 was lighter than the 2x2 with a bigger wing area, I must of misunderstood all the blurb when they brought this out, do you know what the weight difference is?

Interesting that the Spin 99 gets hotter, as you say this may be because of the ducted fan drawing more amps, what sort of amp draw is it compared too the 2x2?

What would you do with hindsight about the side thrust, would you build it in, or use a mix on the Tx? I would appretiate your comments.

Mike

didiwatt

My Feedback: (38)

Dave:

Any idea of how many watts you are putting out on your 2X2? I would also be interested in what kind of motor mount you are using. I don't see where AXI makes a mount with a support for the rear of the motor.

I am working on a twin and would like a system capable of 3,000 watts per side on 10 cells.

Thanks, Paul

BaldEagel

AXI do this type of mount for all their motors, go to the "Model Motors" web site and you can down load their catalogue that has all the information you will possibly need from prop size too amp draw.

Mike

BaldEagel

Paul

If my calculation are correct you are building a twin which is going to weigh 40Lb @ 150watts/Lb (generous) that is some twin you are building what is it?

Mike

BaldEagel

Few more pic's, the first shows the Plett in the conventional position without the front former fitted, this allows me the choise if the C of G is too far forward, will have to take out the front former that is now fitted and shown in the second pic, I will brace this back too the mid former, the next two pic's show the range of battery position I have by making the tray movable, again for C of G adjustment.

Mike

BaldEagel

Further pic's showing the Plett in position on its temporary mount to get the spinner clearance.

Mike

didiwatt

My Feedback: (38)

Mike:
Round #2 of this baby which only lasted 4 flights. At 40 to 45lbs, I figured I would need 150 watts per lb to take it off the grass.

Paul

BaldEagel

Paul

This may interest you: http://www.modelmotors.cz/odkazy/01/index.htm half the expected weight of yours, but if you double up, way over powered I think.

Have you downloaded the Model Motors catalogue yet?

Mike

BaldEagel

Front motor support now braced, time to put the motor on and check the proposed C of G with the servo's placed in various positions, this will have to wait untill tommorow as its dark outside and my GT is calling.

Mike

didiwatt

My Feedback: (38)

Mike:
Yes I have been to that website numerous times. I like their calculator also. Very interesting article on the 33% conversion, thank you. 7000 watts out of that baby, wow................
Paul

BaldEagel

Dave W

According to Composite's web site the 2.1 has a lower wing loading than the 2 x 2, that can only be achived by a larger wing area of lighter weight, if you are saying its heavier then its got to be the larger wing area? as you are a rep for the company I must bow to your superior knowledge, how much lighter is the 2 x 2?

Using the old 2 x 2 fusalarge mould for the new 2.1 explains why the gel finnish around the front is so bad on all the examples I have seen.

Mike

BaldEagel

Well with two 5955's hanging off the rear, batteries and motor in position it was slightly nose heavy, so I have the rudder servo, Rx and Rx battery to play with to get the CofG in the ideal position, looks like my fears where unfounded, I suppose the motor being off the front has helped more than I thought it would. The inside of this thing is going to look very empty with no tank and other things associated with an IC version.

Mike

BaldEagel

The original Lord mounts allowed to much movement of the motor, so these have been binned in favour of some modified ISO mounts from my MVVS petrol engines, I have also now installed the Kodiak switch for the A123 Rx battery and the final arming plug on the outside of the fus, the maiden flight should be done somtime this week, but keep looking as I will post some figures from the installation during the next four days or so.

Mike

tIANci

Bald ... can't wait to see her fly. She looks like she is coming together really good. I sold mine to a friend who was dying for a composite plane.

BaldEagel

Ian

Was yours electric? and what did you replace her with?

Mike

tIANci

Bald ... I did not build her, was about to after you started this thread. My pal wanted my Comp AFR really badly so I thought no point having 2 big EP planes, I got the MidWest CAP 232, that bird has flown. My pal flies much better than me so the Comp ARF will be better off with him. I like your workmanship, most neat. Love the switch too, very cool!

BaldEagel

I don't know if you have the details of the Fromeco Kodiak switch, Just in case its designed for the A123's, but can be used with anyother battery, fail on, can handle 30amps, will allow charging through the front deans of 10amps, and the display adds up the amount of current consumed during the flight, and keeps adding it up on consecutive flights until you zero it, I consider it a major contribution to safe flying, they are going in all my bigger birds as are the A123's, charging on the field has never been easier or quicker with the advent of these batteries., looking for a small charger to allow top ups on the field, the TP610 I think it is looks the favorite at the moment, I already have a Bantam 902 for workshop charging.

If you liked this build, did you see the Dual Carbon Horns I put on it?

Did you do a build thread on the CAP? if not why not?

Mike

Sorry IAN going off line now, speak tomorrow.

tIANci

Ian ... the Fromeco sounds totally cool! Yeah noticed the CF horns, nice touch. I did not put up a build thread as it was built for me and to put it together as an EP was as simple as any ARF. Hehehehe ... if you want I shall put up some pics of I can send you some pics via email. PM me if you wanna see them. Its really simple. I need to change the horns etc, I was lazy and used simple ones, not a really good idea!

BaldEagel

Finnaly got the Plett up and running on the Anyliser, temp 1 is the batteries and temp 2 is the ESC supprisingly because of the wind from the prop the temps go down during use in a ground run, I doubt if this will happen in the air, the wave form for the ESC is from the anyliser hence the jump in amps every 10th cell approximatly on the spread sheet, prop used was a 22x10 RASA's folding on the in spinner Plettenberg, all looks very promising with 56amps and 6200rpm should fly well.

Mike

Well theres a thing can't import Excell spread sheets.

BaldEagel

Saved the file as a TxT format, hope all can read it. Just looked my self and you will have to move all the headings over one to get the true picture.

Mike