Hi guys, after lots of requests, I've finally made an 80mm fan for all you Habu32 flyers. It originally seemed like an odd size fan, but Eflite's reasoning that they wanted to stay with a 6S pack seems quite sensible now that I've done it, once you go over 6S you get into multiple packs and extra cost etc. A single 6S 5000 pack can give you 2kW+ of power and still get 3-4 minute flight times. Power hungry crazies can go for more cells if they wish, of course. So, the new fan is not actually all that new, it's the super efficient SM100-45 rotor cut down to 80mm. I've spent a lot of time redesigning the shaft adapter to keep the weight down, and I'm machining the back of the rotor hub back which allows the rotor to be pushed back a bit further, which is important when the rotor is a bit heavier than most. The motor tube is the same as the new ones I'm using in the SM89-45 and will be using in the SM100-45. It's got a 39mm inside diameter, and is suited for the HET700 series motors or thin case 15 series Neu motors. The motor is fixed via 5 x M3 grubscrews just behind the stators, similar to how Tam's fans are done, it's a great idea from Tam (and probably patent applied for by BVM.....) but it does mean you have to use a good high viscosity thermal grease to provide total support around the motor inside the motor tube, as you're grabbing the motor at the rear and not screwing the front down. I'm using the HET700-60 series, it is very efficient, high quality, affordable and readily available. The Neu 1512's would also be a good choice or perhaps the 1509 but do remember it's a low rpm/high torque fan compared to the rest. For 6S I use the 1738kV version which, on 6S Turnigy 40C 5000's gives a peak of 2.1kW, settling to about 1800W, on 7S it gives about 2.7kW. For 8S the 1485kV gives a peak of about 3.1kW on 40C 5000's and about 2kW on 7S. Those two motors really cover most options that you would consider, although I'd like to try a lower kV and go for 12S 2650's (as I have a bunch of 4S 2650's for my EF-1 pylon racer). As for thrust, 3.0kW gives about 4kg (8.8lb) static thrust, 3.5kW gives 4.5kg, which is more than enough for the little Habu. The shroud is made from alternating layers of unidirectional and woven pre-preg carbon. It's a solid walled tube as that's a lot more durable than a foam sandwich one and only very slightly heavier. It's also made in long lengths by someone else, which means I'll be able to keep up with production rather than spend my time laying up shrouds (which is oh so much fun

). There's no tailcone, as it's tight getting anything into the Habu, adding a tailcone would just make life difficult for no reason other than having a pretty carbon fibre tailcone which you can no longer see. For guys who just have to have a tailcone it's available as an extra. BTW, I just run the motor wires out a slit in the exhaust tube, put some heatshrink around the three of them to keep them in line, then bend them forward and tape them to the shroud and tape around the wire opening in the exhaust.
OK, so how does it perform? I reckon it goes pretty good. I've had quite a bit of flying on my Habu now, and everyone who's seen it perform seems pretty impressed. with a single 6S 5000 pack to charge and the Eflite electric retracts it's a very "no-fuss" model to take flying, which is a refreshing change after playing with the big ones which require a small portable nuclear power station for charging duties. My Habu was built totally stock, except I used JR378 wing servos for flaps and ailerons, Ino Lab HGD250MG's (awesome servo, but hard to find at the moment) for elevators, HS85MG's for rudder and nose steering and a 2A 1100mAh A123 Rx pack. It has the SM80-45 with HET700-60-1738kV motor with 6S 40C Turnigy 5000's and an ICE 100 esc (with red wire removed to disable the BEC). Even though it's stock, it's come in at 8.0lb RTF which was a bit of a shock as I'd heard of Habus weighing 8lb with 8S 5000's. Still, it flies very well, and with this moderate power setup it's not lacking in performance at all. I'm using the stock exhaust tube as well. Basically, I wanted to see how it would go if the stock fan was replaced with the SM80-45 and everything else left the same. Here are a couple of videos showing how it goes. It was pretty windy that day, so I was landing without flaps, and still getting used to the model, but it gives a pretty good idea. The wind was buffeting the mic on the camera, so it's hard to hear the fan, which is actually very quiet. The stock 66mm dia exhaust is ~100% FSA for this fan, which surprised me after I worked it out, as we would never dream of flying an EDF model with a 100% FSA exhaust. I have tried going smaller and it goes faster, loses vertical etc, as you'd expect, however the sound gets louder, probably due to increased exhaust velocity.
Now that you're convinced you have to have one, where do you get it? Well, if you're at Ejets this weekend, go and see Billy D from USA RC Jets, he will have 10 of them by Friday. With some luck there will be a couple of SM80-45 powered Habus flying around all day. Once Billy D runs out there will be a 2 week wait as I'm just about to head off on holidays (bad timing, I know, can't help that!) but on my return I'll be able to catch up pretty quickly. If you want a plug and play unit it can be ordered directly from me, which I prefer for plug and play units of all sizes as that way the whole thing is covered by a Stumax warranty and I know it's been setup and run up at full power before you get it. The price? The unit by itself is $320US, a HET700-60 series motor will add $110US. A tailcone will add $30US.
I have to say I really like this size model and fan, Eflite nailed it with this one. Can't wait to see what their new release is like!
Stu.