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Posted by nsg | Dec 05, 2021 @ 05:18 PM | 55,053 Views
A quick how-to on using an eAnSys gearbox with a 24"-26" prop, based on my experiments, other people's posted data and some calculations.

The optimal rpm range for a light CF 24-25"13" pitch prop seems to be 6200-7000 rpm, 6kwt or less. 6200-6500rpm for a 26" prop, about 7.5kwt. Props differ, of course, so look up data for your prop. This post mostly deals with Falcon Electric CF.
  • Use the Single-Gear-L gearbox. If you want to use the 26" prop, get the power expander. That ensures more of the belt in contact with the motor pulley, so the belt can take more load.
  • Pick a 5-6kwt heli motor if you are looking to use a 24" or 25" prop, 7-8kwt motor for the 26"
  • Target rpms, the expected voltage and your motor's kV will let you estimate the GB ratio. Alternatively, you can pick a GB ratio and adjust for motor kV.
  • Get a couple of extra pulleys, to adjust based on your measurements/flying preferences. eAnSys gearboxes can be tweaked for lower rpm/more flight time or more power - takes about ten minutes to remove the spinner/prop/cowl, replace the pulley and put it all back together.
  • I'd like to turn a Falcon CF electric 24x13 at 6500 rpm. That should take 130-140A, so 6kwt max, so probably no need for the power expander.
  • I'll use the 2.57 to 4.0 version of the gearbox. Motor rpm under full load are (prop rpm)*(gb ratio). We get 16700 to 26000 rpm.
  • I need the unloaded motor rpms to compute the motor kV range, so divide by 0.9 (
...Continue Reading
Posted by nsg | Nov 11, 2021 @ 08:52 PM | 8,098 Views
My eAnSys review as originally posted was met with some hostility from a competing vendor, so it is now buried under five pages of nonsense. I'm reposting in my blog for future reference.

eAnSys is a German vendor. They offer a variety of gearbox products targeting different planes and pilots. E.g., there's a 370g gearbox - takes up t o 5kwt, suitable for gentle flying. On the other end of the spectrum is the competition XL gearbox, good for aggressive 3D and up to 15kwt. There's a less fancy 3D gearbox, and a 30kwt monster.

The overall design appears to be optimized for variety of the products while reusing the parts as appropriate. The gearboxes are made in Germany, the motor gears appear to be sourced, and of course so are the belts.

I got this gearbox. eAnsys suggested a Leopard LC700-690 motor - cheap at $100, light at 440g, good to 160A burst at 12s. I decided that my curiosity alone was worth $100, and I did want a motor under 500g so I could keep the overall weight down. This is now installed in my EF 85" MXS, and the motor, set up for 7kwt max, seems to be doing fine. I don't think I would have believed it if I didn't test the setup myself. I will in fact be changing the gear ratio to bring the max power down to 6kwt or so, since that would be more than enough for me. The gearbox design makes tweaking the setup trivially easy.

I could have gotten away with a smaller gearbox for significantly less money (and slightly less weight), but I wanted that...Continue Reading
Posted by nsg | Oct 30, 2021 @ 08:50 AM | 16,297 Views
Misc notes, mostly for myself

Empty airframe ~4300g, firewall to spinner backplate 170mm.

Component placement:
Tail moment measured at wing tube 0.5kG * 52" = 26 kG-inch (suspended the airframe at wing tube, placed tailwheel on a scale, got 500 gram-force)
So components, when installed, should create an equivalent nose moment.

3 tail servos + hardware at ~44", 3*80G * 44" = -10.6kG*inch
motor + prop + spinner + standoffs, 1.4kG*18" = 25.2 kG*inch
ESC, 240G*12" = 2.9 kG*inch
Total for fixed position components, 25.2 + 2.9 - 10.6 = 17.5 kG*inch . This is a rough estimate, so I'm disregarding components close to the CoG, such as wing servos, Rx battery, etc.

Batteries may be moved to adjust CoG, so
batteries, 1.3kG *x, where x is between 3" and 10" (accessible battery tray)

x = (26 - 17.5)/1.3 = 8.5 kG*inch/1.3kG = 6.5", which gives adequate room for adjustments with the rudder servo in the tail. So rudder servo in the tail.

Powerplant options:
- eAnSys competition gearbox (in transit now), configured to match EF Xpwr60
- DualSky GA6000-180 (in transit now)
- Falcon 24x10, wood and CF (start with wood, once confident in the airframe, swap out for CF)
Will use a combo of regular/XXL EF standoffs for eAnSys at ~160g, XXL standoffs for Dualsky at ~120g.

ESC: Castle Edge 160HV
Batteries: SMC 2x6s5300mah. EF recommends 4000-5000mah. I expect the eAnsys setup to come approx. 200g under the recommended Xpwr60, so I can afford the batteries to be slightly heavier.

"And perhaps it will fly. We shall see!"

Edit: it did fly, and what a lovely plane it is. The c.o.g. calculations ended up a couple inches off: my batteries start ~6" from the firewall and end about 1/3 inside the cowl. My eAnSys gearbox is 1100g as installed. If your electric powerplant is less than ~1000g installed (i.e., including standoffs, bolts, etc. - all you need to attach it to the firewall), you might consider pull-pull for the rudder servo.
Posted by nsg | Jul 25, 2020 @ 05:24 PM | 7,076 Views
These motors don't seem to have a very consistent kV. The two motors I have have unloaded kV of 380 and 387. The attached data is from a 387 kV unloaded. Castle Edge HV60, Xoar 17x6, Hyperion G8 HV 2x4s2800. Castle firmware 4.25.

Peak 1950 wt, settles to 1700wt or so, 9000rpm at roughly 80% efficiency.

I use that setup in my 60" EF Raven and 60" EF Laser (slightly less power due to slightly lower kV). It's.. a bit too much power, but certainly a lot of fun.
Posted by nsg | Jul 07, 2020 @ 07:45 AM | 7,683 Views
https://www.aircraft-world.com/aw/fi...r_eos_chargers . Need a Windows computer.

Update instructions attached.

The latest firmware supports HV lipos. The UI, two lines of text controlled/edited by buttons, look archaic compared to modern touchscreens, but the chargers still work well.
Posted by nsg | Jul 04, 2020 @ 12:10 PM | 10,402 Views
EF 69" Raven

MotrolFly 4315 -367
Xoar 17x6
Castle HV60
2x4s3300 mah HVLI Hyperion G8
Approximately 1900 wt max, settles at 1700.

EF Laser 60"
MotrolFly 4315-367
Xoar 17.6
Castle HV60
2x4s3300 mah HVLI Hyperion G8
Approximately 1900 wt max, settles at 1700.

3DHS 70" Slick
Hyperon Z4035-299, 299 kV
Castle Phoenix HV85
Xoar 18x10
Approximately 2kwt max
9.5lb AUW

3DHS 68" Velox
Hyperion ZS4025-16, 320kV
Castle ICE 75
Xoar 17x8
About 1600wt settled
8lb AUW

3DHS 62" Osiris
MotrolFly 4315-300
Castle ICE 50
Xoar 16x10
2x4s3300 HVLi
About 45A max
12 minutes on average
6.1lb AUW

3DHS Vyper 65" (sold, already missing it)
MotrolFly 4315-300
Castle ICE 50
Xoar 17x8
About 50A max, settles to 45-47A
12 minutes on average
7lb AUW
Posted by nsg | Apr 12, 2020 @ 08:08 AM | 8,218 Views
Quick notes from recent conversations, mostly for myself.

Geared setups suddenly make sense, in 3kwt+ space, anyway. A typical direct drive outrunner setup performs at 80%, give or take. I'm too lazy to figure out why, but it is an observable fact for existing outrunners. It is possible to find a high-speed motor that will output the same power at 90-95% efficiency and convert it to a usable form via a timing belt-based gearbox, at a cost of about 2%. Claimed total efficiency about 90% + some weight savings at 4-6kwt, good reviews from the field. See this blog for details.

Gearboxes available:
Filtework: http://www.flitework.at/tb50zr.html
eAnSys: https://eansys.de/?k=7&lang=eng
VELTNIC: https://www.phacebook.com/groups/148...8077553404117/

Design parameters for a 3D setup
- starts to make sense at about 3kwt, give or take.
- gearbox to support gyroscopic forces from a 24-28" prop
- motor optimized for efficiency in 30%-70% power range, with at least 85% at full power, about 20-30K rpm range
- at least 50V, so kV in 500-700 rpm/V range, lower is better.
- package to fit a typical 74" or greater 3D plane. Most of these are designed for either electric or gas, so there's some room for offset gearboxes.

Proper power setup for servos:
- Needs to support two stalled servos for about 30 seconds, all four stalled for a few seconds w/out shutting down the receiver.
- servo extensions do contribute some voltage drop, so 20ga wire where possible
- servo connector is rated for 5A continuous; observed safe for 10A bursts. Above 10A, two servo plugs from a power source to Rx. Above 15A, use a receiver with a separate plug for a flight battery.
- No BEC for 70+ models: use a flight battery. If using BEC, review the current rating carefully. Most BECs are rated for peak power under certain cooling conditions. Using a battery helps you separate the power circuit from the signal circuit (always a good thing)
- for larger models, measure servo current draw at max deflections before the first flight.
Posted by nsg | Apr 04, 2013 @ 08:43 AM | 9,015 Views
I use 5.5 mm PolyMax bullets for my larger batteries. If I were to start over, I'd probably go PowerPoles, but I've too many batteries/planes already set up for bullets.

My problem with the bullet connectors was the negative bullet - it is exposed. I fried a parallel charging board by accident once - touched exposed battery negative bullet with an exposed charger positive. I found a way to fix that.

Amazon sells a 10mm OD/8mm ID plastic tubing. 10' cost me something like $15. A piece about 7/8" long fits over the negative bullet nicely, held in place by a drop of hot glue. No more exposed bullets.
Posted by nsg | Dec 30, 2011 @ 05:03 PM | 9,477 Views
Maidened a 62" 3DHS Osiris today. Bought a slighly damaged kit from Mr. Irg, repaired, moved the motor & ESC from my 3DHS Vyper, servos left over from my Extra SC, had to buy a roll of midnight blue Ultracote, a new receiver, prop and a spinner. Total ended up about $270. Not bad for a very good pattern plane.

Hyperion H4025-12, ICE 100 Light, 5s4000mah, AR6210, Xoar 16x10, 3x Hyperion DS-16FMD, 1x HD DS-120M (rudder)

Exact match for Osiris dark blue covering: Ultracote, Midnight Blue, HANU885


Posted by nsg | Oct 21, 2011 @ 08:07 PM | 10,324 Views
Not only Flying Styro is back (who'd have thought..), but they are offering some pretty nice deals at the moment. Buy three kits and get free shipping + 10% off. I finally took them up on it - Mosquito, An-2, Supermarin S-6. I have their Yak-3 ad love it.

For those who haven't heard of FSK, it's a Czech company (no, not Alfa.. that's another Czech company) known for highly detailed - count the rivets - scale models that happen to fly extremely well. Hobby-Lobby used to carry them.

Posted by nsg | Mar 26, 2011 @ 06:58 PM | 10,874 Views
Another toy..

Mega 16/25/2, Turnigy 85A ESC, turnigy 6x5 prop
2x HS-65HB, AR500
Motor mount by SmallPartsCNC.com (highly recommended)
Hyperion VX 4s2600 mah

About 55A max, 26-27K rpm.

I think Ultra is a nice improvement over the regular FunJet even if you don't go with a high-performance setup. I flew it on a 400 wt setup while waiting for the Mega, and it flew fine.

I need something better than an AR500, and something better than the TGY ESC, too. All in good time.


Posted by nsg | Dec 15, 2010 @ 09:11 AM | 11,078 Views
.. so long and thanks for all the fish.

(sapienti sat, and I don't mean the Hitchhikers Guide)
Posted by nsg | Oct 26, 2010 @ 04:51 PM | 11,269 Views
Maidened the Aspera I bought from Tim at the NJ 3DHS Throwdown. It takes some getting used to - the only pattern plane I've owned before was Brio, and that doesn't really count. I need to get used to it, but the first impression is very positive.

EF Torque 2818/900, APC 11x5.5, 4s2600mah for about 500 wt. ICE-50, 4xHS--65MG, AR6200. AUW about 1300g or 46oz.
Posted by nsg | Oct 20, 2010 @ 09:19 AM | 11,989 Views
Castle is running a clearance on their test motors. I ended up with three, more or less out of curiosity.

Motors seem to be high quality. Castle being, well, Castle, cross mount holes and holes for a bolt-on adapter do not correspond to any motor I know of. The shaft isn't easily reversible, the grub screw is difficult to access. A Turnigy 42-xxx bolt-on adapter almost fits, the bolt holes need to be filed by 0.5 mm or so. The bolt pattern for X mount looks to be 24x30mm.

3412 series weight 155g, 3422 - 250g, 3434 - 300g.

3412-770. This is pretty close to Hacker A30-12XL, except it weights less. With an APC 13x6.5 on 4s, I got 45A, 8300rpm at 14.7V. 30 seconds at WOT didn't overheat the motor, so it is probably good for 14x7 for 3D. Should be a reasonably good fit for something like 3DHS 51" Slick. Of course 3DHS provides a discount on a Hacker motor bought with Slick at the moment, making Hacker a better deal.

3412-450. Looks to be a good motor for 13x6.5, or possibly 14x7 (pushing it) for 3D at 6s. This will probably work on a 48" EF plane, or most 3DHS 48" ones - it's basically the same as a 150g 900 kV motor on 3s. Short-term max current looks to be about 30A.

3434-250. Needs a high voltage setup. Should be good for about 1500 wt at 10s. Max short-term current looks to be about 35A. 3434-450 is probably a better choice for your typical 65-70 plane, and a good value at $50 compared to similar high quality motors.

Castle was going to market these at $150-200, I believe. Not sure they are worth that much to most people, but they'd certainly be competitive in $100-120 range. 3412-770 and 3434-450 look to be very usable and a decent value at clearance prices.
Posted by nsg | Sep 11, 2010 @ 08:54 PM | 11,841 Views
Reichard Sirius. 3m wingspan, about 2200g AUW. Maidened today, with much appreciated help from Mr. RCEverything.

Relatively easy build, excellent performance. Near vertical climbout with a fairly modest power setup

5x Hyperion Atlas DS-16FMD servos (wings, rudder)
HS-65HB elevator
Hyperion GS-3020-782 motor
Castle ICE-75 Light ESC
Zippy 30C 2200 mah battery
Aeronaut 14x8
About 500 wt max
Used up 900mah in 20 minutes.
Posted by nsg | Apr 10, 2010 @ 07:19 PM | 11,872 Views
WildWing-1.avi (8 min 12 sec)

The famous $12 keyfob camera mounted on my WildWing.
Posted by nsg | Mar 27, 2010 @ 02:12 PM | 11,559 Views
I almost crashed my 3DHS Vyper 65 the other day. This is (more or less) an investigation log (more or less) for myself.

Equipment as flown:
Hyperion H4025-486
APC-E 17x8
Castle ICE-100Light
4x Hyperions DX-20xSMD
Spektrum AR6200
ValueHobby GForce 4000 mah 5s

What happened:
Loss of radio signal for about 5 seconds. Recovered in time for less than graceful landing, slight damage to cowl. Could have been a lot worse.

What do I know at this point:
- All equipment expect for battery has been flown before
- AR6200 mounted reasonably well, satellite receiver far from main one. Rx been used on my HK-450 heli for several months, had three problem-free flights in Vyper prior to accident
- The plane was in first quarter of a large loop, full throttle, going up
- ICE log shows full throttle up to loss of signal. Battery voltage very reasonable.
- Total servo current is about 1A. Stalling a servo doesn't increase it all that much. The Hyperion spec says nominal curren 0.2A, stall current 2A per servo.

Other data:

68 Velox crashed, BEC/ESC failure. Same equipment I'm using now.
Brownout on a similar setup
Apparently, ICE BEC is only good for 3A (peak? not sure) at 20-24V. That would make brownout a possibility.

  • Asked Castle's help to interpret log data. Castle rep did their new 'ripple voltage' song and dance before we settled on faulty battery conenction as one possible cause. Remember Patrick's "you all use crappy motors" song and dance?
  • Switched to 5.5mm bullet connections for ESC/battery
  • Twisted wire extension (it's 30") for the tail servo.
  • Found that Castle BEC won't connect to Castle Link if it's soldered to ESC leads as it is supposed to. Apparently USB current leaks into the ESC and shuts down the USB port. Figured out how to make it work - plug in a 2s battery. That will help out the USB port, now it all works. Heh.

Posted by nsg | Mar 18, 2010 @ 12:15 PM | 11,888 Views
Okay. EF is hereby nominated for the 2010 funniest customer mailing award. Strong runner for the all-time record award.

(Sapienti sat)
Posted by nsg | Mar 17, 2010 @ 09:24 AM | 11,815 Views
(Notes to myself)

CoG 170-180mm off leading edge == between centre and tail side of the wing tube

Low rates per manual
Ailerons 42mm 30% expo
Elevator 17mm 30% expo
Rudder 52mm 30% expo

High rates per manual

Ailerons 83mm 70%expo
Elevator all the way 75%
Rudder 77mm 75%


Ailerons 15 degrees == 42 mm gap at the wing root
Ailerons 30 degrees == 83 mm
Aileron width at root 160mm

Elevator 15 degrees == 17mm at counterbalance
Elevator width at counterbalance 65mm

Rudder width at counterbalance 100mm
Rudder 30 degrees == 52 mm at counterbalance
Rudder 45 degrees == 77 mm
Posted by nsg | Mar 12, 2010 @ 12:01 PM | 11,867 Views
January 2010, shot from my Cularis. Not too bad for a $14 camera.

LMT-from-above-jan-14-2010-cut-0.avi (9 min 16 sec)