rorrock

Coming Soon.... New Stumax 90mm & 100mm fans..
Thats right the master himself has some new fans coming.. super high quality and power in smaller packages.. Why buy fans put together from different sources when you can by the one package, made locally and by one of the most recognised names..

The two new fans designated SM100-45 and SM90-45, being 100mm dia and 90mm dia with 45mm hub dia. There's been a demand for a good sounding 90mm fan for a while now

Stu Says
"I originally tried trimming down an SM110-52 but it was too heavy. I had a lot of SM110-45 motor tubes sitting around and as it's not such a popular fan (not sure why, it outperforms everything I've tested it against) I thought 'd put them to use. I used the same stator design as well, just shorter blades and then set about designing a 100mm rotor to suit. The goal for the 100mm fan was 5kW using a Neu 15 series motor. Testing shows that my power vs rpm calcs were pretty close, and a 1521-1.5Y on 12S seems to be a good choice, needs a lot of flight testing to confirm, of course. For the SM90-45 it looks like a 1515-2Y will be a good choice on 12S for 3kW, or perhaps a 1515-1.5Y on 8S - again, this needs to be thoroughly tested before I'll put these figures in stone. The rotors are 11 bladed, with the blades being individually injection moulded from long glass filled Nylon. the blades are assembled onto front and rear rings which lock them all together. Once the rotor is assembled, it is attached to a shaft adapter which then mounts to a dummy shaft in the lathe, then the front face is machined flat and the bore at the front is machined out to accept the aluminium ring which forms the locating face for the spinner. A lot of work and fiddling, but this ensure the spinner runs 100% true. As assembled, the rotors are close to being perfectly balanced, and I've actually run them without further balancing. Production rotors will be dynamically balanced.

Thrust-wise, the SM100-45 is matching the 110mm fans up to 3.8kW then it tails off a bit as expected. On 3.8kW it delivers 6.0kg thrust. The static efficiency is up around 92-94%, which is staggering, really, and the reason it's performing close to a fan with much more FSA. The SM90-45 is giving just over 10lb static thrust with just under 3kW, which is still pretty good considering it's a cut down rotor and loses the aerodynamic tricks I've used at the blade tips. BTW, FSA for the SM100-45 is 6264sqmm and 4771sqmm for the SM90-45. I'll post some thrust vs kW curves as soon as I've settled on the right kV and length motors.

The SM90 is basically the SM100-45 rotor trimmed down to 90mm, using the same motor tube (although I'll make them shorter later on for shorter motors to save weigh and cost) and a 90mm dia shroud. The shrouds are carbon/Rohacell sandwich construction, although if they prove popular enough I would like to go injection moulded, as making sandwich construction shrouds is too slow and tedious for my liking, and it means they are black and boring.

I'll be flight testing the SM90 very soon in a HET Super Sniper and the SM100-45 in the FeiBao F5E. I'm pretty confident both fans will be class leaders performance-wise. Sound-wise, the SM100-45 is quieter than the SM110-52 but the sound isn't as interesting, simply because the SM110-52 was designed to have certain pleasing harmonics, and the SM100-45 was designed to be super efficient (hence its quietness).

I'm not into vapourware so I'm not promising a release date. I'm hoping to have first batches done within one month, but don't hold me to it as I won't release them until they are 100% right. Please register your interest with your local Stumax dealer, or if you don't have one in your region, please feel free to email me. There are a few production things to be sorted, such as the shaft adapter which is currently the same tapered collet arrangement from the SM110-45 but I'm finding it's almost impossible to get a grip on the tiny rotor blades to tighten it all up. This will probably mean a set screw type shaft adapter which brings its own headaches as the fit on the shaft has to be perfect with zero clearance. There's also the issue of having mounting rails moulded into the shroud or not - what do you guys prefer? For production it's easier to have the rails moulded in (BTW in the pics you'll notice the sides of the SM100-45 shroud have rough looking patches - they are from the peel ply I put there so I didn't have to roughen it up to glue the mounting rails on), but some people may not want rails at all, preferring a flange mounting."

I hope you like them, I'm pretty excited about them.

speed is life

Thanks for posting this.........I had not gotten fired up to do the thread as Stuart only did a formal announcement a couple of days ago.

These new fans are in the final test stages at Stumax; there should be a couple of pre-production test examples in the hands of "trusted agents"  in the USA and UK by sometime early Summer.
The fans are set up to accept the Neu 1521, 1524, 1527 series motors.

I will be offering these fans in the USA through my Stumax authorised Performance-EDF distributorship.

I have started a "first come first served" list for serious buyers; price is still to be determined. 
They won't be cheap, these are not cheap asian knock offs of something else.......

This is the Stumax website:
http://www.stumaxaircraft.com

This is Performance-EDF:
http://www.performance-edf.biz
(I don't have this new fan on the site just yet)

Cheers,
Mike Warren
Larkspur, Colorado, USA

rorrock

Mike,
No problem.. I'm doing the same in terms of a list for the APAC region (and anywhere else there is no dealer)..
It took 5 hours from announcement until the first one was reserved...

Regards,
Rob