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Sep 19, 2017, 08:00 PM
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Originally Posted by mongo
where is home, now, Par?
I'll be in Corpus Christi, TX for a couple years.
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Sep 19, 2017, 08:12 PM
Lee Liddle
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Hang in there buddy. First things first.
Sep 20, 2017, 11:50 AM
BFMA #13, aka Rogue 13
mongo's Avatar
i get down there every now and then. will have to find you.
Jan 10, 2018, 09:43 PM
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Hey guys,

I'm back after a bit of a break. I've been working slowly over the past few months to improve the high power design to ensure it will run safely for many, many flights. The main issue was the use of adhesive as the only method of ensuring structural safety at high RPM's. This simply is not enough to operate any fan that uses plastic blades. At this point, I am very familiar with the failure point and as a result, I was able to work out a process of using 3 screws that screw into the rotor hub to retain each blade. I will post all the details here in the near future but just wanted to let you all know that I have not forgotten about this project.

Additionally, I am just about complete with testing of the 18s/22lb fan and will be selling it next week with an ESC and motor RTF. Below are two test videos on 16s and 18s for all the details. This is an excellent fan for A/C in the 20lb range with a max thrust of 24lbs and settled thrust of 22lbs. If anyone is interested, please shoot me a message or just look for the ad in the classified section next week.

I also plan to make the 18s setup available as a kit with motor/ESC/new rotor blades/intake lip/tailcone/all hardware over the next few months. The projected cost is $800 shipped.

The other two variants that will be available will be a 25lb fan and the 30lb fan. Both will come fully assembled and tested with ESC as well. Details to follow!

18s/22lbs settled:
Dynamax EDF V2 w/TP-5670-542kv on 18s/8ah Nano-Tech (4 min 54 sec)


16s/18.5lbs settled:
Dynamax EDF V2 w/TP-5670-542kv on 16s/8ah Zippy Lipo's (4 min 41 sec)
Last edited by Par_18; Jan 10, 2018 at 10:37 PM.
Jan 11, 2018, 03:45 AM
Lee Liddle
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Awesome work as usual Par. I know how much time, energy, and money you've put in to development of this kit/turn key option for the Dynamax fan. I predict that it will be the "go to" fan for a large number of EDF fliers. It won't be just a flash in the pan like so many other Dynamax convertions have been in the past. I'm anxious to get mine in the air this Spring.
Based on your extensive testing I'm sure that the performance and longevity of the package will be first rate. Not to mention that it will be in a class by itself when comparing bang for buck.
Jan 11, 2018, 08:02 AM
3d and EDF, some scale
MustangAce17's Avatar
Wow Par, very impressive! Would love to own one of these one day if I ever strike it rich , can't wait to see what some of the guys do with them
Jan 11, 2018, 08:19 AM
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Thanks for the words of encouragement Lee. I think the fan is on the right path now with some of the changes to take it up to the next level. It will certainly be a good competition for the $1500 fans on the market.
Jan 11, 2018, 08:28 AM
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Quote:
Originally Posted by MustangAce17
Wow Par, very impressive! Would love to own one of these one day if I ever strike it rich , can't wait to see what some of the guys do with them
No need to strike it rich for some serious power any longer. Let me know when you are ready to build something and Iíll be sure to get you a great deal.
Jan 11, 2018, 08:30 AM
3d and EDF, some scale
MustangAce17's Avatar
I hope to be getting some good $$ here before to long and if that happens I will definitely take you up on that

It just occured to me I know a local guy that has a Byron BD 5 I could use to try it
Last edited by MustangAce17; Jan 11, 2018 at 08:49 AM.
Jan 11, 2018, 09:24 AM
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Any thoughts of a cut down 120mm version? If so, what kind of thrust, effux,numbers might that look like. I have a 120mm, 25+ pound fan being completed as we type. It cost about $2,500. I would have liked to have spent half that.
Jan 11, 2018, 10:23 AM
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Quote:
Originally Posted by Scottfpv
Any thoughts of a cut down 120mm version? If so, what kind of thrust, effux,numbers might that look like. I have a 120mm, 25+ pound fan being completed as we type. It cost about $2,500. I would have liked to have spent half that.
Scott,

It is certainly in the realm of possible but I do not have the funds or time to explore it right now. However, it is something I can look into in the future. The bigger challenges of mating it to a motor and running it safely have pretty much been overcome at this point. I fee it will not be so difficult to cut down the rotor and then itís a simple matter of determine the right motor. $2500 is certainly a lot of money for a fan IMO but others may look at it differently.

My goal this year is to get the price down to $1000 for the 30lb fan with ESC RTF. I have not fully determined the current cost but It will likely be around $1200 with ESC. This is about the maximum point of efficiency for the Dynamax and most 127mm fans.
Jan 12, 2018, 04:53 PM
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30 lbs for $1200 would be the best bang for the buck ever...IF you could get 200 trouble-free flights out of it.
Jan 12, 2018, 06:53 PM
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Quote:
Originally Posted by Fanflyer
30 lbs for $1200 would be the best bang for the buck ever...IF you could get 200 trouble-free flights out of it.
Don't know about 200 but I plan to do between 50-100 cycles before I call it good. Previous failures have occurred within the first 5 runs at this power setting so if it survives 50 runs, I will be confident. The measures I am taking to strengthen the blade retention is many magnitudes stronger than the stock setup. If it fails now at 40k, I will be very surprised. I figure run it 2 times day, everyday until I hit 50 cycles. Take it all apart and inspect for any stress fractures. If I don't find any, we are golden.
Jan 13, 2018, 01:01 PM
Registered User
Watch the middle screw of the three blade-retention screws - highest probability of stress crack formation because it straddles the joint between blades and interrupts the flow of force along the edge of the blade shoe...
Don't know that you need it anyway. Keeping holes as far away from edges as possible is one of the first things we learned in building full-size metal airplanes. Not sure if it translates to fiber-impregnated plastics, though..
Jan 13, 2018, 08:19 PM
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Quote:
Originally Posted by Fanflyer
Watch the middle screw of the three blade-retention screws - highest probability of stress crack formation because it straddles the joint between blades and interrupts the flow of force along the edge of the blade shoe...
Don't know that you need it anyway. Keeping holes as far away from edges as possible is one of the first things we learned in building full-size metal airplanes. Not sure if it translates to fiber-impregnated plastics, though..
Good idea...I'll keep an eye on it. Past failures have only occurred at either the front or rear portion of the blade base where it is notched to fit in the rotor hub and rotor cap. As long as the blade is not allowed to move there, I think it will be OK. I think it will be sufficient but testing will find out for sure.


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