Max Amp

[Tim Mackey]

Hi Jet... quite right too ....unfortunately - as we expected - ol' grumpy wants a great big 60" span beast along with all his other criteria for the £110 project , so probaly not likely to go for that particualr feature!

As we of course know...something like the super little ALFA Sabre is ideal for such a thing, having removable wings and being pretty light and compact as a result.

How's the hawk looking - which  motor did you go for 1600  or 1800 KV ?

OOps...off topic

[Myron Beaumont]

Timbo

Actually you are wrong about me liking leccy - I am a steam engine fan and was brought up on a farm, so I don't mind muck and mess. But I agree about a clean and quiet pilot!

Think we should have a "cheer up grumpy Myron" thread? Just like the cat - never happy!

Chrissy

[Tim Mackey]

"Won't cost you very much more than £150!"

yeh, but 'ol grumpy wants the thing in the air for 75% of that figure, with 2 spare batteries as well !! 

[Steve Hargreaves - Moderator]

Blimey....talk about light blue touchpaper & run!!!!!! Seems I missed all the fun after challenging Myron to put his wallet on the line. What say you guys ??? Should we post up a Find Myron An Electric Package thread on his behalf.......

All joking apart, everything in your wishlist is achieveable Myron but it would be rather expensive!!! Suggest setting your sights a litle lower until you know if you like electric or not!!!!

 Poor Phil...we seem to have completely hijacked his thread.......just to get it back on topic (& this is a bit spooky) but when I said the Emax motor was familar I found out why........I'd just ordered one from UH in HK & it arrived Friday afternoon!!!!!!!! So I now have exactly the same motor as you Phil....!!! Mines going in a Shocky type model....wot you doin' wiv yours????

UH offer two different kv values on this motor.....1200 & 1534...mines the 1200 version & it spins an 8x6 slowfly on a 3S battery very nicely whilst pulling 12A...perfect for my application. The 1534 model suggestes 7x4 or 7x6 as typical prop sizes......see here

 Just out of interest Phil where did yours come from

[Phil Robinson]

Hi Steve

             my Emax came from Hong Kong, cheap, and very fast delivery considering . It is fitted in a little high wing trainer at the moment.

              The other night I tried the motor using different props mainly APC type I checked the current on all the applications and got to the point where a 9 X 5 GWS prop gave the best results. It pulled a max amp at about 14A and gave a thrust at approx 680g. OK the thrust measurement may not be accurate but all the tests were done in the same way so it would give a good indication of whats happening with the different props. I will have to get a selection of smaller props and see what they measure up at.

Regards Phil

[Myron Beaumont]

Hi guys!

Thanks so much for advice etc. Am now researching 'lectric power & visited sites recommended.

Sorry Phil for hijacking thread but have been seriously motivated to try to control potentially explosives.If it goes pear shaped. I hope you'll all be here to help.

EDF's appeal - something slowish flying like e.g. "A10 Tank Buster". Yes! Two EDFs but I can then use one for smaller aircraft if one blows up assuming that it is easy to move the units around installations (like an IC engine).

Have decided to up the budget . 'Er indoors says she is going to Provence on her own so that leaves me another tenner  That's what I told her anyway . The things I sacrifice to get what I really want, not just enough for the present (a bit like choosing R/C gear).

I have already started to by checking out my 2 dry powder fire extinguishers.

Jetsome - I also like "FILIP" @ Puffin Models & the idea of  what is called AXI 2808/20 to power it but am confused -is it a kit -what do all the numbers mean? How much is a charger.

Can't find any reference to the Alpha Sabre. Who makes it?

[Tim Mackey]

ALFA not Alpha. here

[Myron Beaumont]

A wee bit too pricey Timbo But thanks Just been reading your tutorial/ info on the charger & am impressed. If I ever find exactly what I want I'll let everybody know .I WILL find it !

[Steve Hargreaves - Moderator]

He's getting closer guys.......not long until he cracks methinks!!!!!!

Phil...I tried a GWS 8x4.3 on mine last night.......nice draught for only 10A!!!! No idea of what that is in grams though....I tend to go for the "hold-the-model-vertical-whilst-flat-out-&-if-it-feels-like-it-wants-to-go-its-probably-enough" method!!!!!!!

[Steve Hargreaves - Moderator]

I should probably post this in another thread but I too really like the Sabre & fancy giving EDF a go....Jet/Timbo...you both have this model yes? What set up do you use? The CML website shows a 4980kv inrunner but no spec (current wise) plus an 1800mAH Lipo.....what do you use??

& do I have any chance of flying this on 35Mhz..................??

[Phil Robinson]

Hi Steve

              I must admit that I too tend to rely on your method of testing thrust  but for once I just hung the model on a digital fishing scale to get a feel for what it relates to in grams.

Thanks for your help and advice

Regards Phil

[Tim Mackey]

I too use the hanging under power method, and of course the usual watts per pound rule.

My Alfa Sabre uses an AON 4900 KV inrunner, with the standard alfa fan ( fan is supplied with the kit but NOT the motor )

A 2 wind mega fan motor is also a great choice, but ensure the fan supplied will mate with the mega...early Sabres did NOT

I started off using a 1500 EnErGy 3s , but moved to 1200 F/P EVO20C 3s and this is IMO perfect. The little bird likes to kept light ( THE golden rule for all EDFs ) and she flys off from a simple hand launch easily. I actually have no issues at all with hand launching, and have no access to tarmac strip, and do not want the added weight or drag of the drop tanks - just my personal preference. Just remember to allow it time to get on step, and do NOT use elevator until the speed has built up....I let mine get away, dip and lose altitude, then gently feed in a little up eleveator for a smooth and shallow climb out - works fine every time.

Once on step and up to flying speed she flies beuatifully, as on rails, with a little characertistc fishtailing in any cross wind, keep the speed up in the turns as it does tend to dig in a little, but it will slow quite well for a straight low pass down the strip, and landing is easy too....just not too slow.... but a doddle really.

Always check the mouth and throat ( of the model silly ) after every landing for F.O.D.

It is expensive for a foamy, but IMO worth every penny, with an a excellent finish, nice decals ( which scuff easily unless a light varnish is applied over them ) get the COG spot on where they recommend, ensure the thin steel control wires are free moving, and have some fun....it has a super sit and presence in the air.

Heres mine captured by our ace club photographer on a nice fast pass. It is not a rocket with this setup, but trust me... it is scale speed, looks right, and I get around 7 minutes flight. I stress again - KEEP HER LIGHT

As Jetsome says......one of if not the favourite model in my collection at present, and I have had her for around 2 yeras, and she has about 100 perfect flights and landings under her wings so far.

[Tim Mackey]

I too suffered some glitching with 35Mhz - even using top quality schulze rcvr, and jeti ESC.

Went to spekky about 15 months ago ( this was my first model to be converted ) and not a single hint of any problem whatsover since. I even now have the esc right next to the rcvr which is normally a no-no for 35mhz gear of course.

The picture above was pre spekky days, as was I suspect that one of Jet's, judging by the long dangly wire aerial

Sorry we have gone way off topic.  

[Steve Hargreaves - Moderator]

Thanks guys.....all interesting stuff. I've always loved the look of the Sabre but as you say £100 is a lot for a foamy. I was aware of the fan/motor shaft interface from a different forum. Apparently locktite green is recommended but I can't help thinking this is a recipe for disaster on a fan spinning close to 50,000rpm.

To summarise then...top notch lightweight Lipos 1200-1500mAH (keep the voltage UP & the weight down).....around 5000kv motor on standard fan........top notch Rx & Esc to avoid the glitches (I think a move to 2.4 would make it a VERY expensive foamy!!!).......typical 9g (torque 1.2kg) servos be OK or something a bit more substantial needed......

Just one other thing....the forums talk about extending the motor wires from the esc to keep the battery to ESC wire short, others say to extend the battery/ESC wires & not touch the motor side......I'd always understood the battery to ESC was the side to keep short as the induced EMF spikes can kill yer ESC......any thoughts.....

 Yeah, sorry Phil...we've nicked yer thread...AGAIN!!!!

[Tim Mackey]

extend ( if you must ) wires from ESC to motor preferable ) reasons you think are correct.

Standard mini servos are fine. The green loctite is supplied with the kit, and is all I have used to secure the fan hub adaptor to the shaft... It is SOLID

The bit about the mega motor mismatch is nothing to do with fan to shaft...the motor is just too large in diameter to fit the early sabre fan shroud. When you see the model finished, and especially after you have flown her....you will see that it is worth every penny of the 100 quid or so price tag.

[Steve Hargreaves - Moderator]

Balsamart is my local!!!!!!!!! Can't say I've ever seen any Alfa kits in there though........

Zippy LiPos from HK?? I've just got some of those LoongMax jobbies from UH......not hugely impressed with the voltage stability........despite being 20C batteries the voltage is down to just 9.6volts at 10C which is disappointing. They might improve after a few cycles I suppose......