Electrifying Sig Riser 100
 

Do any of you have any recommendations for converting a Sig Riser 100 to electric. Any suggestions as to prop, motor, control, batts. or your experiences would be appreciated.
Fred123;)

RE: Electrifying Sig Riser 100
 

What does it weigh now?

How steep of a climb do you require?

Thermal soaring I presume.

RE: Electrifying Sig Riser 100
 

Mine does well with a KDA 22-20, 11-8 prop and 2200 LiPo. Dave

RE: Electrifying Sig Riser 100
 

Kit is on order, but expect a flying weight of around 70 oz. I have been building and flying GS gas for a number of years and thought I would like to try my hand at an electric sailplane for thermals and general open field flying..Fred123

RE: Electrifying Sig Riser 100
 

Lockley's got it about right. any motor capable of 250 - 350watts. and under 1000rpm/V. I'm lifting a 3meter, similar home built. At 170watts, and up. 300watts is a lot for a 2 peice wing. 11 X 8 folding prop is a good start. Make sure you program in a soft start, and brake, this will save a lot of wear on your folding prop.
Hope this helps, -Snuts-

RE: Electrifying Sig Riser 100
 

One of the ways to size this is using watts/pound.

At 70 ounces you will be 4.5 pounds. If you target about 70 watts/pound you should get a strong climb. So something in the 300-350 watt range should work very nicely.


Using the Rimfire configuration too:
http://www.electrifly.com/config/

Performance Trainer
Motor 35-36-1500 / GPMG4625
Gear Ratio N/A
Gear Drive Not Required
Propeller 12x6 in., Electric
Battery 3200 mAh, 7.4v

ESC SS-60 / GPMM1850
ESC Motor Adapter GPMM3123
Motor Mount Medium / GPMP1255
Current Draw 47 amps
Approximate Speed 44 mph
Approximate Thrust 47 oz.
Weight of Power System 10.5 oz.
Approximate Flight Time at Full Throttle 4 minutes
Watts per Pound 79.54

This would work

RE: Electrifying Sig Riser 100
 

aeajr:(or others)

Thanks for your quick response. I see that tower has discontinued the 35-36-1500. I was considering an AXI 2820/10 with a CC 45. What are your thoughts, especially on the prop and which would fit best, a 2s or 3s battery?
Fred123;)

RE: Electrifying Sig Riser 100
 

Good choice for the motor. KDA 22-20 is another option from Hobby City. Same with the ESC.
3s 2200 mah li-po. 10-6 to 11-7 folder. Will give you some pretty good times and climb rates.
Past experience with a Riser 100 and an Oly II with similar setups have been excellent.

No worry about the battery fitting. Plenty of room in the fuselage.

RE: Electrifying Sig Riser 100
 

I have ordered the AXI 2820/10 with a folding, 40mm spinner for a 4mm shaft . Any thoughts on whether the engine needs to be mounted through a new firewall or radial (surface mounted). Fred123

RE: Electrifying Sig Riser 100
 

Fred123,

I believe tht the guys that i know just used the stock plywood motor mount (bulkhead) to mount the motor. Just make sure it has some reinforcements to beef it up a little. It will be fine. See if I can find the pictures from the builds.

RE: Electrifying Sig Riser 100
 

This is my effort at mounting the AXI 2820/10. I have located a new 3/16 in. firewall at the location shown on the plans for the original. I have installed with 2 deg. of right thrust and 5 deg of down. In order to be able to round the nose down to accommodate the 40 mm spinner, I faced the firewall with a 1/4inch pice of soft balsa. The holes in the sides and top are there for motor cooling. My only question at this point is where the CG will fall with the motor mounted this far forward.

RE: Electrifying Sig Riser 100
 

Fred, is that plywood on the mount? CG will be the same as on the plans. What I use is 1/8 light plywood and triangle stock a short distance to be able to sand a rounded nose. Dave

RE: Electrifying Sig Riser 100
 

Lockley: I used 3/16 plywood (not lite ply) faced with 1/4 inch of light balsa for the firewall. I put 4 small square pieces of baswood (about 1"long" in each corner behind the firewall. This allowed me to sand off the corners of the light ply sides and bottom to round the nose. Wouldn't have needed to round off so much if I could have found a turbo spinner larger than 40 mm. This is my first electric, so I am probably building it much stronger than necessary. My last two planes have been a TF GS P-47 and a Balsa USA Spad XIII.. What I meant by my CG comment, was I was afraid it would make it nose heavy to have that much weight in front of the CG. I do hate to add lead..FRed123

RE: Electrifying Sig Riser 100
 

That's a 5mm (shaft) spinner right? I mounted the battery under the wing , servoes up front. Used the bec; no aux. battery. No lead required. Assuming riser is similar to Spirit 100

RE: Electrifying Sig Riser 100
 

Very good Fred, you should be set up well. Let us see the bird when you finish.

RE: Electrifying Sig Riser 100
 

I expect to also put the batt. under the wing and use a bec.. Yes KMR1, the motor shaft is a 5mm. Question. Do you install a switch to turn off the batt supply to the ESC to stop batt drain between flights? Would be a lot of trouble to remove the wing each time. I have heard that some use an automotive spade fuse as a disconnect. The CC ESC is rated at 45 amps. Any thoughts..Fred123

RE: Electrifying Sig Riser 100
 

fred123

You can use a switch if you like, personal choice, but most just plug the battery into the ESC before flight an unplug after flight. Just make sure the connections are under the canopy hatch. This is so that you are not constantly removing the wing and reinstalling every time you need to change the battery.

Are you bolting the wing on or using rubber bands?

Got to agree with Lockley. You guys are doing a great job so far. Looking forward to the finish and maidens.

RE: Electrifying Sig Riser 100
 

The wing will be bolted on.. The connection under the front hatch is a good idea. That would only require removal of one screw... ...Thanks..Fred123

RE: Electrifying Sig Riser 100
 

Try using a a couple of rare earth magnets or a canopy latch in place of the screw to hold the canopy on.
Either would be better then a screw, where you could slip and cause damage to the plane.

RE: Electrifying Sig Riser 100
 

Attached are pictures of the completed Riser 100. My worry about being nose-heavy was unfounded. I ended up locating the battery in the compartment ahead of the leading edge and moving my servos forward to just behind the leading edge bulkhead. Total flying weight was 58 oz. The AXI 2820/10 should really make it climb.I plan to try to fly it tomorrow (Friday) if the weather permits. I will report back after that. Fred123

RE: Electrifying Sig Riser 100
 

fred123

Great looking model. Job well done. Good luck on first flight.
Think you are going to enjoy this one.


tink

RE: Electrifying Sig Riser 100
 

Maiden flight: Got to the field about 1:00 pm . Weather was about 60 deg, wind at about 7 or so mph. Range check ok, but on loss of signal motor started to run at about 200 rpm. I wasn’t able to figure out why. Xmitter was set on fail safe and should have cut the throttle. Oh well, time to fly. Plane climbs like a rocket, cut back to ½ throttle and that was plenty. The flight went like clockwork. Second flight also was good. Wind has picked up some. On the third flight, the wind aloft is getting fairly brisk. On the climb out, increased to full throttle and suddenly got a violent , right wing flutter. I immediately cut throttle just in time to prevent a complete wing failure. Landed and inspected it, but no damage. Looks like full throttle in windy conditions is a no-no. On the last flight, the wind has continued to increase and on the landing, I got too slow, letting the wind get under a wing, putting me into a cartwheel. The nose cracked just in front of the leading edge. The advice in the forums to reinforce these bulkhead areas is correct. Just wish I had done it. All-in-all, the day was successful. The damage is an easy fix, and I won’t make that mistake again. The flutter was a scary thing. Have any of you had a similar experience? ..Fred123

RE: Electrifying Sig Riser 100
 

I repaired the damage last night and flew again today. The wind was just as brisk, but I was a lot smarter. Here area couple of pictures..Fred123

RE: Electrifying Sig Riser 100
 

Great job there Fred123. Looks good in the air with the colors and contrast.
Now you need to to get that 1 hour flight in. Thanks for sharing the pictures.

RE: Electrifying Sig Riser 100
 

Tink: Thank you and the others that have so freely given me advice on this project.. It sure helps avoid those first time mistakes..Fred123