skinut

Just built a sig wonder with .25fp and I'm in the process of covering. Can anyone recommend what servos I should use? Need to order some but have little experience with mini servos. Thanks

rcguy59

My Feedback: (8)

Hitec HS225BB or 225MG will save some weight, but standard servos like Futaba 3004 or Hitec 425BB will be fine. It's a small bird, don't get carried away.

skinut

Thanks. I have a pile of spare standard futabas but figured I would save weight and wanted to be sure to order something that would hold up. Thanks again

Crazy4Flight

My Feedback: (540)

Hitec HS-81 on the throttle to save weight, HS-225BB will be fine for elevator & ailerons.

To get more power (RPMs) put a .40 FP carburetor on your .25FP it will fit I have done this. The bore in the barrel is larger.
Also take the baffle out of the muffler and then drill/ream/dremel out the taper in the exhaust exit.

To go completely BONKERS install the O.S..25FX or O.S..32SX

skinut

Hs-225 it is ...What battery pack would you recommend? Where could I find a .40 FP carburetor? How much would really be gained from it?

dbacque

My Feedback: (3)

Skinut,

You sir, are going to have a blast! I've got a Wonder with a Jett .25 on it that I fly almost every trip to the field for the last season. In a word, it is Fassssst!

I just opened mine up to get the exact servos and I have Hi-Tec HS85-MG's on control surfaces and an HS82-MG on throttle, just because the local HS only had 2 85's. I don't know how fast it is but on the first flight it was clocked at 120 mph. That was before the engine was broken in. After breaking in, then switching to speed props and then doctoring the props, it's lots faster than that. Your FP should get you some pretty zippy speeds and if these servos have stood up to the abuse I've put them through, you should be good to go.

Be aware, that I had a problem with aileron flutter in dives. As I've done on planes in the past, I added some aileron counterweights and it's all cleared up. Fly fast, fly hard!

As for the battery, I'm not sure what I've got in there but it's a 4 cell NiMh pack from Radical RC. They appear to be full size AAA cells, so with the current lineup at Radical, that would be 720 mAh. I thought it was smaller than that but I can't pull the battery to check it. However, you're going to need to stop and breathe after a flight. Personally, 2 or 3 flights on this thing after flying something else is all I can take. And I've hardly touched the batteries at that point.

Be aware that putting a .25 on the Wonder means you're going to have to do some serious work on balance. I mounted my battery to the interior fuse wall, right at the very tail end of the plane. The elevator and throttle servo are mounted right in front of that, entirely behind the wing. I made a nice little hatch, wait... I'll take a picture ...

So here's a couple of shots for you, one showing the hatch and where my servos are. The battery is actually behind the servos and the receiver is in the bubble wrap you can see in front of the servos. My engine is heavier than yours, but with all this mass shifting, I only needed to add 1 ounce of lead to the tail for perfect balance. Move things around to suit the weight of your engine.

Don't mess with the counterweights unless you really need to. Fly it and if there's flutter, it's probably aileron flex. Then add the weights. Mine are 3 3/4" from the outer end of the ailerons. They're just fishing weights soldered to music wire and I can now fly the plane in full power dives without flutter. While I usually hang these below the wing if I need them, these are above the wing since it's a belly lander. I didn't want them to act like tail hooks.

Dude, you're going to have a blast! After you get things settled in and trimmed, after doing big, long passes, start zooming it around in figure 8's right in front of you. Endless loops. Pull hard, it can take it. Wow, what fun!

Dave

dbacque

My Feedback: (3)

Duplicate post.

skinut

Yea I cant wait!! Hearing that has me excited... One thing i did to aid in placing the battery and servos was to bolt the stab down. (pic attached) Simply removing it gives access to the entire fuse. I also added front wing bolts. I read that the dowels and f2 were a weak point. F2 actually broke rather easily on me when i installed the tank. So i opted to bolt the front of the wing down. Just need to get it covered now..Thanks again for the pointers.

rcguy59

My Feedback: (8)

For your RX battery, use a 700mah 6.6V LiFe battery. They are very light, compact, reliable, cheap and can be charged very quickly. The voltage is low enough that you don't need a regulator. Every one of my planes, 1/2A to turbine, use this type of battery and I've yet to have a failure. Fire hazard is virtually nil with LiFe batteries.

Crazy4Flight

My Feedback: (540)

I gained about 600 Rpm. Look here in RCU or Ebarf for whole or parts motor or R/C swap meets. I was thinking it was a 40D carburetor. But that was the 40/46 LA carb which is a rear needle valve.

dbacque

My Feedback: (3)

Skinut, very cool what you did with the stab. You'll have a much easier time getting to the battery if you need to mount it as far back as I had to.

Now that you mention it, the LE dowel mounts were definitely a weak point. I filled that entire area with block balsa, then put the dowels in. That worked too. No doubt the stock version of the dowel mounts wouldn't stand up to our kind of abuse.

Best wishes. Your plane is going to be loads of fun. I fly mostly pattern but I've got lots of other planes. Ever since I built the Wonder, it's the only secondary plane I bring to the field anymore. Practice pattern, then zoom around like a maniac. Man, it's fun! I never expected to enjoy this thing this much. It was just supposed to be something silly to throw together.

Here's a shot of mine if you missed the earlier thread. Note that this shot is from before I added the aileron counterweights.

Dave

MJD

My Feedback: (1)

Well, if it fits the Jett .25, it will fit the Jett .35. That would be about as wild as you'll get in a .25 case. Stands to reason somebody has done this already.

p.s. HS-225's are plenty strong. They'll work in a .40/.46 Demon.

Crazy4Flight

My Feedback: (540)

My third Sig Wonder built with .25FP a with 40 FP carburetor. Had a Front wing bolt as well as a bolt on stab. The hatch on the bottom of the fuselage was eliminated and fully sheeted with triangle stock in the corners. Long ago I post this mod as well as several others, like dual rudders, and a change in the way i did leading edge. I used 3/16 spruce in place of 1/4 balsa and the wing sheet went on top of the spar instead of the butt joint. Also pictured is a Lanier Shrike OS .46 FX after a year of flying with stock muffler I added a tuned pipe.

The second picture is my "Wonder Stik" named for the covering scheme and a friend Wonder bot Had OS.15 FP

Crazy4Flight

My Feedback: (540)

A better picture of my Wonder Stik. Also Is a SIG Kommander with powered By OS.46FX

JPMacG

My Feedback: (2)

I have had two HS-225MG fail. I no longer will use a HS-225MG anywhere but throttle. I'm not saying yours will necessarily fail. This was about 10 years ago. Maybe Hitec has changed the design. But that is my experience for whatever you want to make of it.

Mikie 1

Hey skinut, glad you asked. I've built and flown the same airplane and really enjoy the 25 size engine, it really zips around. About the servos, for me I've put the HiTeck HS 82 MG servos. They are small, but strong enough to do the job very well. I've intentionally used the "MG" servo because of the metal gears. The gears are strong and hold up to abuse. Powering the Sig Wonder with a 25 size engine is going on the upper side of power for that plane, so I opted for the stronger servos. I've never had any troubles with them. Good Luck!! Merry Christmas!! Mikie

Strykaas

OS .15LA + hs81 here. No issue.