Scorpion Outrunner power in my Rigger

[yurkanip]

Hey all, I have been tuning my rigger now for a few weeks, as some of you may have read my post on the 6s rigger only going 37 mph...more and more testing KNOWING this hull should be able to run in the 60s...I have narrowed it down to the magnets in my feigao being the problem. Rather than tearing apart my 1/8th scale buggy for a brushless motor, I decided to go way out on a limb here and order a very high powered outrunner for testing. It is the Scorpion hk 3026-1600kv motor to be used on 6s. Max Watts about 1470watts at 70 amps. Magnets capable of 392 degrees F. and only $74.
I have been on many heli and airplane threads, and all of the users call these little motors, torque monsters. The 1/7th and 8th scale unlimiteds have been running the hk 4035 series on 8s with great success and no water cooling (since it is an outrunner). I thought I would give it a shot. since spec wise, it is higher amps and watts than the feigao xl series....take a look at the pics...at the size difference. If these motors, can push a 43inch hull...the smaller version Has to be able to push a light rigger. Testing tonight...can't wait. The kv and amps/wattage of the motor I am testing is similar to that of a 10xl. Only difference is the size...but there really is no comparison between an inrunner and outrunner based on dimensions alone. I ran it in my shop for a few seconds last night and this thing whines!!! it has a very unique spool-down action and sounds MEAN...again not what I expected out of an outrunner....it almost coasts...not an abrupt stopping action like an inrunner.
Will give results in the morning.

[Ub Hauled]

I have been using the 4035 on my 1/8 scale and it is a torque monster... the thing pops wheelies at almost any throttle position... I'll probably have to add weight to get her to stay in the water.

[yurkanip]

Thanks Ub hauled...good to hear others on this forum using them with success. What timing are you using? The only thing I have read is the heli/plane guys are running them with success at 15 degrees timing. Heard the motor stutters at 7.5 degrees and doesn't like 0 degrees at all. also on the other end of the spectrum..24 degrees it doesn't do well either. Guess its due to the fact that it has soo many more poles than an inrunner.
Let me know what you run at. Thanks.

Patrick

[Ub Hauled]

I have no idea, I cannot remember... I'll have to check to be sure... I am using a Phoenix 110HV, it has a lot of options... I am leaning towards 8 degrees, she has not stuttered but I'll get back to you on that one.
I think 12 degrees will generate too much heat.

[Raydee]

What size is that rigger? I am really liking the outrunner idea.

[yurkanip]

Raydee. the Rigger is just about 34" sponson tip to rudder. 17" wide. This model outrunner has potential. The hk 3026 also has a 1400 kv, and 1900kv..(which I originally thought would be a good 4s motor). I might still try that, if this motor works well in my testing. The quality of these motors is the best I have seen out of the motors I have used. (have never owned a neu though, to compare to).

[Raydee]

Nice to see a manly sized rigger for a change
Keep me posted on how that boat does with the outrunner.

[yurkanip]

OK...did some tests today. results not bad, but I was expecting more. The motor literally was a match exactly with my feigao 11xl performance wise and speed. BUT it was cooler after a hard 3 minute run than the inrunner, by a bit. Speed was right around 40mph still...not faster nor slower. Running cooler must be due to the built in fans, moving around air past the motor. Everything is still tight and turning well. I am thoroughly impressed with this little powerhouse to compare equally to a 74mm inrunner, but was hoping for more speed. going to do some cog adjusting and run the next 2 evenings after work and test test test. altogether, this motor was worth every penny. speed wise, craftsmanship etc.
still waiting to hear back from others on their timing...mainly the guys running them in electric unlimiteds that are becoming a popular boat here in the great northwest.

[Ub Hauled]

There is something wrong... on 6s you are getting only 40mph?!?!
Do you have a video? can you post some shots of the profile of the strut?

[yurkanip]

ubhauled...yes, after last nights tests...something is still wrong. This motor is MUCh better quality and equal power to the feigao xl, but still not into the 50-60 mph range..which it should be. I was hoping that with the motor change, I would be right up to those speeds...apparently there is a setup problem still. I am stumped. Will take some pics of rear end, and side shot, to show angle of attack etc. Hopefully someone with a good eye, can pinpoint the problem. Love the motor though, not going to give up on the idea of an outrunner in my rigger and reaching 50-60 mph.

[FRED]

Scorpion outrunner

Lipos for power; considering the lenght of rigger, your rear is dragging its***. Why i say that is when using nimh which weigh in at 14 oz. for 6-pack and lipos weigh in at guesstimate 9 oz.. Now if the depth of rigger between the 2 sponson supports was deep enough to slide one lipo halfway under the front lipo would help in cg arena. Now from pictures, i would guess the whole tub bottom is dragging which needs air under to get your speed. I have built quite few riggers and cg was close to 50% of lenght with turn fin right at 1-2" behind the right sponson. My turn fins were made adjustable, so i could slide fin back and forth with my waterpickup on the left sponson which you only need for esc in this case. Beautiful rigger BTW. Now with all that torque, how about a bigger prop as your rpm will be down due to a outrunners low rpm. I found this out going from brushed to brushless using 7.4 lipo. My brushed was a 12/2 Sonic II motor with a 632 prop with 7.4, it flew, due to higher rpm. Then i put a 28-45-3600 on 7.4 and a 632 and couldn't get on plane. Answer was lack of rpm due to less voltage. I then put a Grauper 1.4-37.5mm cf prop on and hang on.

[yurkanip]

Fred, thanks for the compliment and for the insight. I was thinking that a larger prop might be in order. Also...I can double stack the lipos either in front of the motor, or between the sponson booms. (its not pretty considering how thick the lipos are, stacked...but this is testing right now). From what I gathered in your post...you think not only the rear is dragging, but the whole tub? I have the strut as low as I can make it. ( next rigger will not use a center ski. I will use two adjustable rear sponsons) The rear ski I have on it now. limited my dropping the strut, from beyong a point. Which is where I am at now. I think that moving both lipos way up front, will cause a heavy nose....and probably would not turn very well...but I am not sure if that was what you meant.

The outrunner is great...now I have to just keep tweaking and make this thing fly. I am also going to try it in my other rigger that is in the paint booth right now(same hull, only a narrow nose like the sgx) This hull is about an inch longer and has a more aggressive angle of attack, a tad bit more than the hull I am running now.

I think you are right with needing more lift overall. maybe adding rear sponsons, will create that? OR could make it run hotter, due to more drag...not sure. I have a set of sponsons drying from clear coat..so might just stick them on with double sided tape...for the hell of it. I am at the point of trying ANYTHING to make this hull run at the speeds it is designed for (being a nitro 70 mph hull, this coming from the designer of the hull himself who gave me the set of plans)

[sailr]

I'm encouraged to see more people trying outrunners. Don't be fooled though about the need for cooling! They will run hot also. You may be getting by with the scorpion because of the fan but don't think that all outrunners will last without some sort of cooling. Even in aircraft applications with that big old fan on the front, proper cooling is critical!

I am convinced that when enough people start using outrunners we will see a whole new paradigm in boat propulsion! We were one of the first to use them in a production boat and it rips. BUT we water cool it also. Regardless if you're using an outrunner or inrunner, excessive heat will demagnetize the magnets, burn up the windings, etc.

[FRED]

Scorpion Outrunner

No reply on whether info reached it's destination.

[Brushless55]

I do not remember who, but someone builds an outrunners that can take 395*f without issues.