Thread Tools
Sep 25, 2019, 06:38 PM
Ldm
Ldm
Ldm
Ldm's Avatar
Thread OP
Discussion

Sig Hummer -electric power suggestions


Hi All
Just picked up an old kit from my past ! I would like to build this as an electric model, any suggestion on power ?
Thanks

Specs

SPECIFICATIONS
Wingspan: 34" (864mm)
Wing Area: 212.5 sq in (13.9 sq dm)
Wing Loading: 13.5 - 17.6 oz/sq ft (41 - 54 g/sq dm)
Length: 30.75" (781mm)
Flying Weight: 20 - 26oz (567 - 737g)
Airfoil: Full symmetrical
Sign up now
to remove ads between posts
Sep 25, 2019, 06:51 PM
I just want to go fly!
walter3rd's Avatar
I’m building a 35” twin and I’m using dual 50watt himax motors. Not sure of my finished weight though. You can zoom In To see it on the plans. 223 sq- inches
Sep 26, 2019, 01:39 PM
Pro Hoarder
turbonut's Avatar
Any thing that makes about 200 to 300 watts and it will scream...Use a 6 to 8in prop . And a KV that will turn 15 to 25k rpm depending on the prop size
Latest blog entry: In flight
Sep 26, 2019, 01:55 PM
AndyKunz's Avatar
My son Ian has one with a either a Mega 16/15/4 or E-flite EFLM2000 (similar motor). It's a rocket. APC 7x5E prop on it.

Andy
Sep 26, 2019, 02:29 PM
B for Bruce
BMatthews's Avatar
As a guide the TeeDee engines make around 100 to 110 watts of power. Hot reed engines 80 to 85 watts.

If you want to fly it similarly to how it would have been with a TeeDee then I'd aim for around 120 to 140 to ensure hot performance when you want it but not so over the top that you end up only using the lower half of the throttle lever movement most or all of the time.

For motors on a 3S pack that means propping them for around 10 to 11.5 amps max. So a pretty small and light motor will do the job.

Equally important will be to find a motor with the right Kv that will give you this power with a 5x4 or 6x4 prop so it works with the landing gear height. Or maybe a 7" prop? This seems to mean that you want to use a motor with a Kv up around 1500 to 1600 give or take.
Sep 26, 2019, 05:10 PM
Slopin Eh!
Funny this thread popped up....literally pulled one of these kits from my stash the other night. Was considering going twin engine.. I'll be watching .
Sep 26, 2019, 06:29 PM
Registered User
Ian Kunz's Avatar
Slight correction on what I have in mine. It’s a Himax HB2815 spinning a 6x4E APC on 30A ESC with 3s. 70-80 mph speed range.
Sep 26, 2019, 08:35 PM
Ldm
Ldm
Ldm
Ldm's Avatar
Thread OP
Would an elfight park 450 work ?

Ohhh correction I think you guys are more in line with the
E-Flite Six-Series Motor Brushless 2000Kv (28mm) EFLM2000
Last edited by Ldm; Sep 26, 2019 at 08:40 PM.
Sep 27, 2019, 12:27 AM
B for Bruce
BMatthews's Avatar
I'm using a Park450 on a somewhat larger model. An older Eflight PT19 with a 44" span and around 28 oz. I hardly ever use full throttle with it even for takeoffs. It normally lifts off and climbs out in a nice scale like manner at around 2/3's throttle. And it also needs a 9 to 10" prop due to the low Kv value of the motor.

Power wise and Kv wise you'll want a smaller and lighter motor and one with a high Kv value. And in fact I think the Park 340 with Kv of 1700 would be a better match. The Specs tab shows an input power of 145 watts. So nicely a bit over a Tee Dee. So perky for sure. And the prop information lists the options on a 3S pack at 6x4 to 6x5.5. I suspect the 6x4 would get the motor running at 100 or a bit more watts and make the model perform smartly like they did when using a Tee Dee. There won't be any vertical climbs off this much power though. But it'll be a pretty steep climb if you manage to keep the weight of the model down to around 16 to 17 oz.

That EFLM2000 would be way over the top in many ways. First off it's a 3oz motor where the original glow engines were 1.5oz for a TeeDee and 1.8 for a Medallion ( I just weighed a sample of each). So it's a heavier motor than the Cox engines the model was designed to use. Next up is that at potentially 26 amps continuous on a 3S pack you're looking at a power input of around 300 watts. Potentially three times the power of the TeeDee. And even on a 5x4 small size prop I suspect it would be a total hotrod. And that for other than short bursts you might never use more than the first half of the throttle stick movement.

Now of course there's always the old saying that "nothing succeeds like excess". And if you want the performance of a lightly loaded Super Hornet on full afterburner then fine. You'd certainly get it with that motor and an 850 to 1200mah pack.

But if you're going to end up flying most of the time at a power level of 80 watts with occasional bursts for fun that are totally over the top then what about one of the racing quad copter motors? They are really small and light but are rated at up to 400 watts for at least short bursts.

For example, HERE IS ONE MOTOR that is very likely to run well for you at better than TeeDee levels on a 3S pack and with a 6x4 prop. Unfortunately their test data is all done on a 4S pack so I'm sort of guessing that it would be around 100 plus watts on 3S with that prop. You MIGHT want to go with a 6x5 to pull a bit more. Or if you're brave enough go with the 4S option and experience up around 500 watts of power at full throttle..... Don't blame me though if the wings instantly flutter and fly away....

Best of all the motor is not expensive and it's only 1 oz. 2/3's or just over half of what the original suggested glow engines weighed. If you go this route be sure to order the CCW motors so they work with the "normal" model airplane props.
Sep 27, 2019, 07:29 AM
Ldm
Ldm
Ldm
Ldm's Avatar
Thread OP
Wow -GREAT INFO ! THANK YOU
I will follow your advice , also keep the model super light!
I built this model years ago as my second model after a Hal Debot Live Wire Champ !
Talk about going from a Sunday flyer to a rocket lol !
Sep 27, 2019, 07:59 AM
AndyKunz's Avatar
Quote:
Originally Posted by BMatthews
That EFLM2000 would be way over the top in many ways. First off it's a 3oz motor where the original glow engines were 1.5oz for a TeeDee and 1.8 for a Medallion ( I just weighed a sample of each). So it's a heavier motor than the Cox engines the model was designed to use. Next up is that at potentially 26 amps continuous on a 3S pack you're looking at a power input of around 300 watts. Potentially three times the power of the TeeDee. And even on a 5x4 small size prop I suspect it would be a total hotrod. And that for other than short bursts you might never use more than the first half of the throttle stick movement.
Like I said, Ian's is a rocket!

Andy
PS - He flies it like it has a latching throttle switch. What's this "short bursts" stuff!?!?!?
Sep 27, 2019, 09:40 AM
I just want to go fly!
walter3rd's Avatar
Yeah I don’t do the short burst stuff either
Sep 27, 2019, 01:48 PM
B for Bruce
BMatthews's Avatar
I won't deny that full power and "damn the torpedoes" does not have a lure of its own. It's all about what we actually want out of our models. So I try not to be biased but offer up different flavors.

I'm planning on a healthy building time this winter and hope to build a hot quad copter motor powered 4S crazy model as one of the builds. Something very "jet like". Should be a real giggle if I can keep up with it...
Sep 28, 2019, 08:26 AM
Ldm
Ldm
Ldm
Ldm's Avatar
Thread OP
I am sticking with the suggestion guys making sure I get the plane version so I emailed the site.
In the time being I happen to find this motor in my spare box and it’s geared, any thoughts ?
Himax HA2025-4200 Electric Inrunner Motor, 175 Watt

Himax Brushless motors are manufactured to high standards for the discerning modeler. Designed for lightweight, high efficiency, and durability these Himax motors are sure to make today’s radio controlled models perform. Please read the entire operating manual to ensure correct functionality and best performance.

The HA2025 series motor is suitable for small models weighing 12 to 18 oz. direct drive or up to approximately 30 ounces when used with a gearbox.
HiMax
Ha2025
4200

Features:

High Efficiency
High Power
Lightweight
Replacement for 370 - 400 Motors
Specifications:

Weight: 65 grams (2.3oz)
Motor Only Max Power: 175 watts
Max RPM: 60,000 RPM
OD: 20.0mm, (.79”)
Length: 42.0mm, (1.68”)
Shaft Size: 2.0mm, (.078”)
Mounting Screw Thread: 2.5mm, max depth 3.0mm
Mounting Pattern: 16mm (.625”) bolt circle.
Sep 28, 2019, 11:21 AM
B for Bruce
BMatthews's Avatar
Depends on what size of prop is needed to make the motor draw the amount of power you want to use.

I found THIS WEB SITE that lists a variety of Himax motors. Your 4200 version is the last one at the bottom of the page. Looks like the gear ratio is wrong for what you want to do as the suggested prop size is 10 to 12 inch diameter because of the gear ratio. What this would be good for is something more like a big light old timer or with folding blades a light 2 meter powered glider.

The listing for the motor by itself shows a max size of 5x3. And that might work for you. It may also not be too far off the money to use an APC 6x2. But the 2mm shaft would scare me as it's likely easily bent. Strike anything at all with the prop such as in a nose over and it might well result in a bent motor shaft.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Plans search for the original SIG 1/2a Hummer... Danoman812 Sport Planes 3 Jun 08, 2016 11:22 PM
Build Log SIG "WONDER", conversion to Electric power & battery hatch modification!! NewZee Glow to Electric Conversions 33 Apr 16, 2016 08:31 AM
Video Electric SIG Hummer Maiden jasmine2501 Electric Plane Talk 7 May 02, 2008 12:00 AM
SIG HUMMER Glow to E-power conversion. genovia Parkflyers 23 Dec 09, 2002 03:32 PM
power sys for sig hummer conversion jcrazyflyer Sport Planes 0 Mar 04, 2002 09:35 PM