HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jan 18, 2011, 05:07 AM
mty
Registered User
Hungary, Somogy County, Kaposvár
Joined Feb 2009
51 Posts
Question
Supra electric motor choice

Hi,

I have a Vladimir's model electric Supra glass on order and I would like to order the motor by the time I receive the model.

I will use four Hyperion DS095-FMD (19 g) servos in the wing and two Hyperion DS09-AMD (9 g) in the tail.

I'm not looking for extreme power.

Can somebody help me out with an estimation for the weight budget for the motor, propeller and battery pack in order to reach the recommended CG without needing lead weights?

I'm thinking about using a direct drive outrunner, possibly the MVVS 4,6/840 (206 g) with a ~250 g LiPo, but I'm afraid that they will be too heavy for the light tail servos.

Thanks in advance.
mty is offline Find More Posts by mty
Reply With Quote
Sign up now
to remove ads between posts
Old Jan 18, 2011, 05:21 AM
HyperFlight Support
Neil Stainton's Avatar
United Kingdom, England, Stratford-upon-Avon
Joined Feb 2001
3,893 Posts
Have you seen the powertrain suggestions on my site?
http://www.hyperflight.co.uk/product...-E-COMPETITION

In 2010 I was using a HET 2W-25 120g inrunner with a 47g 4.4:1 gearbox and a 3S 1.8ah lipo. The combo ballanced fine without any ballast required, but I was using the older quite heavy extension leads to the DS09 tail servos. For 2011 I intend to replace the extension lead with lighter ones, change to a 85g Hacker A20-6XL motor plus 47g gearbox, and maybe reduce the battery to a 3S 1.3ah 50C pack.

I do like lightweight Supras. Others fit heavier motors and heavier tail servos and are also very happy with their setups.

Neil.
Neil Stainton is offline Find More Posts by Neil Stainton
Reply With Quote
Old Jan 18, 2011, 08:24 AM
Red Merle ALES
Curtis Suter's Avatar
United States, Mt, Helena
Joined Apr 2002
5,547 Posts
I can't help much, but after a lot of help with Neil Stainton, (thanks so much) and lots of research I've settled on a Hyperion GS3020-08 with a 13x7 to 13x8 prop. Flight testing will be in order.

Here's the link to the Hyperion motor.
http://media.hyperion.hk/dn/gs/

I've attached the data that Ecalc gives me which I've found to be quite accurate. Note: Battery voltage is for A123 cells thus it's a little lower than if using Lipos.

I only have the cores cut and tailboom completed so a flight test report is a long ways away!

I just thought you may be interested in the motor data.

Curtis
Montana
Curtis Suter is offline Find More Posts by Curtis Suter
RCG Plus Member
Reply With Quote
Old Jan 18, 2011, 02:03 PM
mty
Registered User
Hungary, Somogy County, Kaposvár
Joined Feb 2009
51 Posts
Thank you for the replies.

Neil, Yes, I have already studied the recommended motor list on www.hyperflight.co.uk, but if possible, I would like to look for a direct drive solution first. If I can't find a suitable option then I will go with a geared motor.

Curtis, I had some Z30 series Hyperion outrunners that I really liked. They look the same as the new GS 30 motors. The diameter of the GS30 motors is specified as 37.5 mm. Is there enough space in the stock electric Supra fuselage for the motor wires?
mty is offline Find More Posts by mty
Last edited by mty; Jan 19, 2011 at 02:38 PM.
Reply With Quote
Old Jan 18, 2011, 04:00 PM
Red Merle ALES
Curtis Suter's Avatar
United States, Mt, Helena
Joined Apr 2002
5,547 Posts
Quote:
Originally Posted by mty View Post

Curtis, I had some Z30 series Hyperion outrunners that I really liked. They look the same as the new GS 30 motors. The diamater of the GS30 motors is specified as 37.5 mm. Is there enough space in the stock electric Supra fuselage for the motor wires?
I'm sorry I can't answer that. I've never ever seen a Supra other than pictures here on the internet. I'm scratch building mine from plans; wings, tails, pod and boom!

Curtis
Curtis Suter is offline Find More Posts by Curtis Suter
RCG Plus Member
Reply With Quote
Old Jan 18, 2011, 06:19 PM
HyperFlight Support
Neil Stainton's Avatar
United Kingdom, England, Stratford-upon-Avon
Joined Feb 2001
3,893 Posts
Quote:
Originally Posted by mty View Post
Thank you for the replies.

Neil, Yes, I have already studied the recommended motor list on www.hyperflight.co.uk, but if possible, I would like to look for a direct drive solution first. If I can't find a suitable option then I will go with a geared motor.

Curtis, I had some Z30 series Hyperion outrunners that I really liked. They look the same as the new GS 30 motors. The diamater of the GS30 motors is specified as 37.5 mm. Is there enough space in the stock electric Supra fuselage for the motor wires?
I don't know the Z30 motor, but I am pretty sure the Hyperion Gs30xx series will fit. I've updated the Supra powertrain suggestions to include some using the Gs3020-08, see http://www.hyperflight.co.uk/product...-E-COMPETITION

I think the Gs3020 will be okay for short burst of 70A max. If you want a higher power setup, or like hotdogging your planes use a Gs3025 instead.

Neil.
Neil Stainton is offline Find More Posts by Neil Stainton
Reply With Quote
Old Jan 19, 2011, 02:35 PM
mty
Registered User
Hungary, Somogy County, Kaposvár
Joined Feb 2009
51 Posts
Thank you! That is very good news.

I think Hyperion doesn't make the Z30 motors anymore, but they are still on their website. Externally they look very similar to the Gs30. Here is the link:

http://www.aircraft-world.com/prod_d...z30/z30all.htm

Actually I have a Z3019 and a Z3025 in some of my models, so I can try them in the fuselage when it arrives and then I will get a low KV Gs30 or Z30.

What is the diameter of the electric Supra fuselage at the front? Could anybody please give me some outside diameter measurements together with the distance from the firewall at a couple of points? Also approximately what is the wall thickness?

Thank you in advance.
mty is offline Find More Posts by mty
Reply With Quote
Old Jan 20, 2011, 10:18 AM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
2,604 Posts
I don't have a life so I spend a lot of time flying and when it is cold and/or dark, testing stuff.

Several years ago I installed a Hyperion HP-Z3205-06 (Kv = 1365) in a 55 oz. AUW AVA. I am running it off of a 2600 3S 45C Hyperion Pack with a 13x7 RF prop on an RF hub and spinner. (Yes, I know that that is a big battery, but with the AVA's rear mounted servos (right now JR DS168's), I still needed a bit of weight in the nose to balance the plane). The performance of this plane has been wonderful. With the original hub configuration I am seeing 3500+ fpm climb rates. Given the nature of ALeS flying I am not concerned about maximizing climb rate for any particular reason, but I AM interested in keeping the plane speed up to give me the possibility of launching 400 or so meters INTO the wind when it blows 15+ mph -- something we see frequently where I live. On the test stand, this arrangement delivers about 3000 gm of static thrust at between 75 and 80 amps.

After a year or so of running this combination I sought to purchase another identical motor and discovered that it was no longer being manufactured. It turns out that Hyperion had discontinued this motor series and introduced a whole line of glider specific motors ranging from their GS 2213 to the GS3032. At this time, however, a 3025-06 was not available. One of my flying buddies purchased the GS 3025-08 (Kv = 867) and we put it on my dynamometer. It pulls about 2900 gm (static) with a 3S pack at 55-60 amps and using one of Vladimir's 26mm (between the fixing pins) hubs and an Aeronaut 16x8 propeller. I mention this because I switched to this hub on my AVA and saw a slight reduction in climb rate -- not a knock on the hub, just an indicator that one can probably use slightly larger props with it than something like the 41mm (between the fixing pins) RF hub.

Both of these motors are excellent choices for this size plane. Neither, however, is likely to be fitted into an AVA or a Supra without leading the power leads outside the fuselage near the nose to be free of the spinning portion of the motor. In the case of the AVA I fashioned a fairing to cover the external portion of the wiring. It does not look bad at all, but it would be wonderful if Vladimir could fashion some nosecones with a bulb to accommodate the wiring for these excellent outrunners.

Right now, I would suspect that other similarly rated outrunners would not fit at all into the Supra nosecone. I am currently finishing up a Supra and as I hold the nosecone in my hand and try to fit the 3025-08 into it, it appears that it would fit if the power leads were led outside the fuselage. But the Hyperion motors have a somewhat long, tapered nosepiece specifically designed to fit into tight glider nosecones. When I look at the current Z series dimensions, I do not believe that they, or other similar motors would fit.

Right now, I am installing an MVVS 5.6/690 (Kv = 690) into my Supra. With a 4S - 1900 pack, an 18x6 Aeronaut on Vladimir's hub i get about 3600 gms of static thrust at around 50 amps. While I will likely get the plane down to minimum weight with a smaller pack, it requires about 20 gm of tail weight right now. The motor is heavy at 260 gms -- but it is a real piece of work in terms of quality. It is an inrunner/outrunner. An outrunner with an outer case that allows the power leads to exit the rear of the motor. I got it as much out of curiosity as anything and may ultimately change it to take a few ounces more out of the plane -- but not now. While the motor is a good fit, it was not an easy fit. While I own a bunch of Vladimir's planes for TD and electric flying and am always impressed with the quality of the workmanship, this plane had several large wads of epoxy splooge left in inconvenient places near the firewall which made the installation of these outrunners a bit problematic. After grinding out as much of it as possible, I ended up fashioning a spacer to set the motor back 2 or 3 mm. While this worked pretty well, it was a problem which solved itself when I put the nosecone on the dynamometer to do a final test on my motor/ESC/battery/prop system. The 17x8 Aeronaut propeller blew itself up at about 1000 rpm below its rated rpm and pretty cleanly separated the firewall from the nosecone. This allowed me to fashion a new firewall, grind out the splooge from the front and put everything together nice and neat and clean. Frankly, after going through this, I wish Vladimir would simply ship the nosecones finished without an installed firewall to facilitate final installation by the builder. Especially, for guys contemplating the use of outrunners, it would simplify things a bunch.

For a while here I had a separate thread with respondents trying to figure out the reason for the prop failure, and while we did not come to any conclusion, I have decided to be careful about running the Aeronauts on offset hubs (I do not mean "twisted" here but offset.). One of the respondents, an engineer, ran a simulation which suggested that there might be a significant increase on the bending load on the prop blade when using the offset hub. I'll be using an RF on the Supra rather than launching, biting my lower lip, and hoping that I don't blow the nose off of the Supra one fine day.

I have an older Neu 1105 inrunner being refitted with a 6.67 gearbox to get me to a 500 or so watt 567 Kv motor which will come in at about 135 gms. This will allow me to explore more or less the bottom end of power that I like for these size planes. The calculations tell me that turning a bigger prop slower with this little motor will not cost much in the way of performance -- although if you are starting from scratch it will cost you a fair amount more in the way of cash.

Based on my fiddling so far with the Supra, if I were to go with an outrunner, I would go with the 3025-08, 3S and 16x8. There is nothing wrong with the 3020 series, but it can't save more than one ounce over the 3025-08 (and maybe not that much if any noseweight is required to balance the plane with it) and there is nothing wrong with being able to get an extra 50 or 75 meters upwind when the wind blows. (I am kind of sensitive to this inasmuch as the final TD contest of the season last year was flown in a honker and I know every plane there would have killed for just a little more flying space to windward -- something that TD planes have no choice about, but which we do.)

Anyway,

Happy Landings,

Don

BTW: You can find good information on the Hyperions at : HTTP://media.hyperion.hk/dn/gs/
dharban is online now Find More Posts by dharban
Last edited by dharban; Jan 20, 2011 at 10:29 AM.
Reply With Quote
Old Jan 20, 2011, 10:36 AM
HyperFlight Support
Neil Stainton's Avatar
United Kingdom, England, Stratford-upon-Avon
Joined Feb 2001
3,893 Posts
Thanks for the epistle Don. All very useful info. I will be interested to hear how you like the smaller Neu powertrain.

Have you done a thread about your dynamometer? Can you use it to measure torque and thus calculate efficiency?

Neil.
Neil Stainton is offline Find More Posts by Neil Stainton
Reply With Quote
Old Jan 20, 2011, 10:39 AM
HyperFlight Support
Neil Stainton's Avatar
United Kingdom, England, Stratford-upon-Avon
Joined Feb 2001
3,893 Posts
Quote:
Originally Posted by mty View Post
What is the diameter of the electric Supra fuselage at the front? Could anybody please give me some outside diameter measurements together with the distance from the firewall at a couple of points? Also approximately what is the wall thickness?.
The outside diameter is 38mm. The inside diameter is probably about 36mm, but as Don says there are often lumps of epoxy/filler around the firewall/nosecone edge.

The firewall is about 3mm thick.

Neil.
Neil Stainton is offline Find More Posts by Neil Stainton
Reply With Quote
Old Jan 20, 2011, 01:15 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
2,604 Posts
Quote:
Originally Posted by Neil Stainton View Post
Thanks for the epistle Don. All very useful info. I will be interested to hear how you like the smaller Neu powertrain.

Have you done a thread about your dynamometer? Can you use it to measure torque and thus calculate efficiency?

Neil.
Neil,

I am preparing some materials to put on our ALeS forum to help with the unceasing concerns we have about power systems. The bad news in all of this is that it is a complicated distraction from what most of us like doing -- flying. The good news is that, while it is interesting (at least for otherwise lifeless geeks), it is not really important for ALeS type of competition. Within a very broad range of possibilities, power system selection is relatively unimportant -- other than getting a nice flyable plane together.

I have constructed both a thrust measuring facility and a dynamometer capable of measuring torque, horsepower, etc. It is all tied into my computer and allows some reasonably prodigious handling of data. And it will be the subject of some of my articles.

But as I have blundered my way through all of this I have discovered that most of the kinds of information which might be remotely interesting to even the most whacked out technoids can be easily obtained -- at least to the level of quality useful for what we are doing -- with data that can be gathered a number of different and simple ways. In the extreme, it is easy to gather much of the performance and efficiency data which would be useful to us with something as simple as the new Castle Creations ICE series of ESC's.

It turns out that there is a huge amount of data in readily usable formats on the loads imposed by the propellers we use. From there, simply knowing the amps, volts and rpm that a motor is using to drive the prop at a particular speed is adequate to estimate motor efficiency, etc. And it also turns out that there is free software online which will allow a person with a motor with unknown performance characteristics to be characterized using a handful of propellers (3 - 5) and something as simple as the CC ICE.

I will be furnishing additional information in the near future.

Happy Landings,

Don
dharban is online now Find More Posts by dharban
Reply With Quote
Old Jan 20, 2011, 01:54 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
2,604 Posts
Since my Supra is sitting beside me right now on the balance stand without a power system in it I decided to do some quick measurements to provide builders with a very, very approximate algorithm for figuring out how the plane will balance with your own particular combination of power system elements.

Start with the equation:

(Motor weight (gms) * 15.5) + (ESC weight * 12.5) + (Battery Weight * 8) - (Tail Servo Weight * 41) = 3867

If the sum of the factors on the left hand side ends up being less than 3867 you may end up needing additional weight in the nose. If the sum of factors on the left hand side ends up being more than 3867 you may end up needing additional weight in the tail.

A plane with a 200 gm motor, a 25 gm ESC, a 140 gm battery, and with one 9 gm and one 27 gm servo in the tail would come to a factor of 3425. It will likely need some additional weight in the nose.

This is approximate and I have prepared it under the influence of pain-killers for some recent neck surgery. Don't plan on suing me if it is wildly in error, but please let me know if your results do not comport with mine.

Happy Landings,

Don
dharban is online now Find More Posts by dharban
Reply With Quote
Old Jan 20, 2011, 03:40 PM
mty
Registered User
Hungary, Somogy County, Kaposvár
Joined Feb 2009
51 Posts
Thank you guys for the very good information.

So I'm afraid I won't use the Hyperion Gs30 or Z30 as I don't want to route the wires externally the fuselage.

Don, thank you for the balance equation. That really helps.
mty is offline Find More Posts by mty
Reply With Quote
Old Jan 20, 2011, 07:46 PM
Flying = Falling (Slowly)
dharban's Avatar
Tulsa, OK
Joined May 2004
2,604 Posts
This is a photo of the fairing I built for my AVA to accommodate the Hyperion outrunner. I had originally intended to come up with a more elegant way of attaching it and then considered that whether or not I attached a skid or a skeg to any of my planes that I always taped the "impact area" on the bottom side of the nose.

In using this I came to understand that it was actually better to tape it on in the reverse position to eliminate interference with the folding prop whenever I restarted it in the air.

It would be nice if Vladimir could mold a little nicer piece, mold a recess in the nosecone and cut the slot for the wiring in his kevlar nosecone for a somewhat neater operation. And as I said earlier, I found it easier to fit and attach the firewall myself to install the motor than it was to work with the preinstalled firewall.

Happy Landings,

Don
dharban is online now Find More Posts by dharban
Reply With Quote
Old Jan 21, 2011, 03:05 AM
Registered User
Manchester, UK
Joined Feb 2009
283 Posts
Hi Don

Hope you have a speedy recovery from your neck surgery (Stiff neck from staring high and far into the sky?)

You beat me to the punch regarding a simplified moment calculation for the Supra. I was intending to write one up for this thread when I completed my current measurements/experiments i n a couple of day's time.

At the moment I'm trying out one of the HET 2W 25 inrunners (2660kv) with 6.7:1 g/box on both 3S using 18.5 x 12 and 4S on a 17 x 9. The 2W 23 version also looks useful for 3S. Like you I had to clear out a load of gloop from behind the Supra firewall area before I could fit my mounting collar.

I've previously used a number of the MVVS in/outrunners and they were all delightfully smooth and sweet. My old Ava uses the same 5.6/690 unit you mention, but on 3S.

You might be interested to know that one of our scientific eSoaring colleagues here in the UK (@PainterS) has developed a useful formula for rate of climb (ROC). Judging from the comparisons with real model data it is giving darn good results over the range of pitch speeds we typically employ in HL electric soaring. You can read the original at www.esoaring.net/forum/viewtopic?f=3&t=928 . I'm sure he won't mind if I include the formula here.

RoC (m/s) = {Pin/(10xW)} x {D/(D+15)}

NOTE: Pin is input power to motor in Watts; W is all up model weight in kg; D is prop dia. in inches.

Converting to fpm and model weight in ozs gives:


RoC (fpm) = 694 x {Pin/Woz} x {D/(D+15)}


As an example, a 2kg model (70.5 oz approx.) using 500W input power to motor with an 18" diameter prop will produce a climb rate of 13.6 m/s or 2685 fpm. Figures well suited to a 200m height limit and 30s motor run with time in hand to get well upwind if required.

Enjoy building and flying

Skip
SkipT35 is offline Find More Posts by SkipT35
Last edited by SkipT35; Jan 21, 2011 at 12:23 PM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Skywalker FPV Motor Choice WEREE FPV Talk 0 Oct 07, 2010 11:55 PM
Question 1000mm hexacopter, motor choice dillema ikorman Multirotor Talk 4 Sep 23, 2010 09:38 PM
Help! Suitable motor for a Supra style E-glider century_series Electric Sailplanes 13 Sep 20, 2010 05:15 PM
Wanted motor gearbox supra Gavin Trussell Aircraft - Electric - Power Systems (FS/W) 3 Sep 07, 2010 11:04 PM