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Old Mar 26, 2011, 03:56 PM
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Midvale, Utah, USA
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so you had control of the throttle and rudder, but not elevator? I dont use the stock servos, but I cant imagine just a little extra weight and speed would be to much for them, even if they couldn't quite move it as far as you wanted, you would still see SOME change... after the crash did you test the controls?
Try gently pressing down on the elevator when giving up elevator command and see what happens, maybe the control horn is loose or the rod is flexing?
I use spektrum s75 servos in mine, definitely not high end servos, and they work fine with my brushless setup....
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Old Mar 26, 2011, 04:11 PM
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Tested the controls after crash ... All responded fine with full throws and no strange sounds ...

Searched for the specs on motor and prop combo on a French site ... A guy there flew a simular kv motor on his MM with AUW 780 grams ... He claims he got 80 km/h out of this combo ...

My MM sure wasnt flying that fast (more than missing bolt that would be )

Maybe better if i get a new motor/esc combo for the MM, more lightweight , and save this 1 for a bigger bird ... the MM isnt made for speedrecordbreaking i guess ?!?

Hope i can control myself
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Old Mar 26, 2011, 04:46 PM
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Had my spycam attached to the MM ,watched the clip and it seems the MM was leaning to the left a lot when in flight, think the heavy spinner and prop must have something to do with that (and the lack of great wingspan ofc).

In combination with some serieus speed + left turn with a dive to gain more speed ...

Another lesson learned : If you wonna go faster, be sure you get the right plane for it ... Not only the motor
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Old Mar 26, 2011, 06:54 PM
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A 3536 motor on the MM. Yikes! They are often used to improve the performance of a PZ Corsair or similar. On a MM I'd say the result would be too heavy and too much torque roll to the left.

A good power system in my opinion is the Turnigy 2200kv inrunner with 7x5 APC prop and 2s lipo. It bolts straight in. For higher speed the same motor on 3s and 6x4 is good.
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Old Mar 26, 2011, 08:52 PM
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BoonVegas, Indiana
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sounds like the bolt wasnt screwed in very far at all and when you turned back into the headwind it finally came completly out.
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Old Mar 27, 2011, 04:26 AM
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Actually the wing (and bolt) came off by crashing it nose-first to the ground ...

No way it came off in flight, it was screwed in correct !

I guess its the combination mentioned above : motor and prop to big ...

Like trying to put a Bentley-motor in a mini cooper
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Old Apr 16, 2011, 12:31 AM
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Australia, New South Wales, Sydney
Joined Jan 2011
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Is the tailwheel all that necessary?

Hello from an excited new Minimag owner! It's my second plane, after the EZ*, and I'm looking forward to the build

I'm a bit uncertain about the tailwheel. At first, I was all for it, but having seen the rather fiddly setup that the manual recommends, I'd just as soon save a few grams and wait for the next plane (probably a FunCub) before I go the tailwheel route.

Am I likely to miss out on anything by going without the tailwheel? I realise that there'll be no rudder either, but I'm building the Minimag strictly as a parkflyer without floats in its foreseeable future.

Looking at one of Jurgen's earliest MM posts, there used to be a pre-formed channel through the foam for mounting the tailwheel (or maybe I misunderstood and Jurgen cut that channel himself?):

http://www.rcgroups.com/forums/showp...7&postcount=28

My MM kit does not have that channel, and I'd have to poke a hole through the tail. The idea is unappealing, given the potential for alignment issues.

What's the concensus - is the tailwheel worth it?

Cheers,
Andre
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Old Apr 16, 2011, 12:48 AM
Heli's rule!
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Midvale, Utah, USA
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I built two minimags, one for me and one for my brother, he wanted a steerable tailwheel, so I built his with the tailwheel, and yes I had to poke a hole through the foam. I built mine without a tailwheel.

basicaly, when taxi'ing, his only advantage was he could turn at a lower speed than me. I would have to goose the throttle a little to turn on the ground.

IMO a tailwheel on a taildragger is unnecessary. Nice to have? sure, but not having one doesn't mean you cant turn on the ground, just that you need to be going a little faster to turn, or goose the throttle.... I say, the less to go wrong the better.
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Old Apr 16, 2011, 05:44 AM
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Andre I agree with Dacaur. I also built one with and without. While I do like that the steering is better with the tail wheel it does put a lot of stress on the rudder foam on hard landings. For the effort I would only bother if floats are going to be used. Good luck with it.
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Old Apr 16, 2011, 11:30 AM
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Quote:
Originally Posted by dacaur View Post
I built two minimags, one for me and one for my brother, he wanted a steerable tailwheel, so I built his with the tailwheel, and yes I had to poke a hole through the foam. I built mine without a tailwheel.

basicaly, when taxi'ing, his only advantage was he could turn at a lower speed than me. I would have to goose the throttle a little to turn on the ground.

IMO a tailwheel on a taildragger is unnecessary. Nice to have? sure, but not having one doesn't mean you cant turn on the ground, just that you need to be going a little faster to turn, or goose the throttle.... I say, the less to go wrong the better.
Quote:
Originally Posted by jewfish View Post
Andre I agree with Dacaur. I also built one with and without. While I do like that the steering is better with the tail wheel it does put a lot of stress on the rudder foam on hard landings. For the effort I would only bother if floats are going to be used. Good luck with it.
Thanks guys. A Minimag without tailwheel it shall be then.

Taxiing isn't something I'm used to, seeing as the movement over ground options are rather limited for a stock-powered EZ*, so if I manage to slew the Minimag sideways a bit, that's more than enough for me. I'd actually bought a pair of HS-65MG servos to use for the rudder and elevator, but I'll save 'em for the next plane and go with HS-55s in the Minimag.

Now I have to work out how to arrange the equipment inside - ah, the agony of choice
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Old Apr 16, 2011, 02:57 PM
Lou
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Quote:
Originally Posted by H2SO4 View Post
Thanks guys. A Minimag without tailwheel it shall be then.

Now I have to work out how to arrange the equipment inside - ah, the agony of choice

The HS-55 are more than sufficent for the task, they will work fine. Which motor have you gotten for the plane and what battery do you intend to use?

For some good ideas on what to do and not to do to a MiniMag, select Thread Tools and then select Show Attachments in this Thread. You will then see numerous pictures of what owners have done to their MiniMag.

One of the better mods is to place a piece of velcro at the rear of the wing, on the bottom side of the wing. Then place the mate velcro at the top/rear of the wing saddle on the fuselage. This will raise the trailing edge of the wing and take out the extra positive incidence that MPX built into the plane. Having done this mod, the plane will fly a somewhat better in the sense that when applying a lot of power at once, the plane will not want to rapidly climb.
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Old Apr 17, 2011, 07:59 PM
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Quote:
Originally Posted by TestUser01 View Post
The HS-55 are more than sufficent for the task, they will work fine. Which motor have you gotten for the plane and what battery do you intend to use?

For some good ideas on what to do and not to do to a MiniMag, select Thread Tools and then select Show Attachments in this Thread. You will then see numerous pictures of what owners have done to their MiniMag.

One of the better mods is to place a piece of velcro at the rear of the wing, on the bottom side of the wing. Then place the mate velcro at the top/rear of the wing saddle on the fuselage. This will raise the trailing edge of the wing and take out the extra positive incidence that MPX built into the plane. Having done this mod, the plane will fly a somewhat better in the sense that when applying a lot of power at once, the plane will not want to rapidly climb.
Thanks for the suggestions. I've got 4 motors lined up for experimentation - the stock Permax 400 with a 20A HK ESC, as well as 3 different 28mm outrunners - 1600, 1200, and 1130 kv. I ought to buy shares in HK.

If the cheapies don't work out, I'll probably end up with a 2212 AXi at 1200 kV or so. My intention is to swing the biggest, slowest, quietest prop that will still let me land on short grass without being a lawnmower.

Battery? My high-tech test rig (hold the motor mount in my hand to gauge the amount of pull, and try not to scream loud enough to wake the baby when the 8x3.8 slow fly raps me a good 'un across the knuckles) indicates that 2S may be sufficient for starters, probably at 2200mAh, 25C, 137g, since that's what I've already got for my EZ* and it appears to be the right ballpark weight. If it turns out that it's too asthmatic, I've got some 3S 2350 packs lying around also.

The wing saddle Velcro mod does seem popular. I'll probably end up going that route after a while, though I'll try it au naturelle at first - just to experience the Minimag as the gods of RC intended.
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Old Apr 18, 2011, 12:16 AM
Lou
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H2SO4 .... give the 1600kv a try. I have flown the MM with inrunner and outrunners from 1400kv to 2200kv. For me, the plane was the most enjoyable with the 1400kv motor. By mounting the outrunner on the inside of the plane, you will be able to maintain the designed CG without needing to move things around or add weight to the tail.

If I recall correctly, when using landing gear, the largest prop size I was comfotable with was an 8x. Much larger than 8x and you run into prop/ground/grass clearance issues.

Eventually, I ended up removing the landing gear and hand launching the MM. With the gear off, the plane handles much differently. What ever you decided to do, you will enjoy the plane. I have two of them and have built two more for others. It is a fun plane to build and fly.
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Old Apr 18, 2011, 02:16 AM
Heli's rule!
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Midvale, Utah, USA
Joined Mar 2005
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I use an 8x4 prop on mine, 1200kv outrunner on a 3 cell 2000mah pack... I also have 2 1/2" wheels on it, so no danger of mowing here, prop is a good 3" off the ground.... The way my motor is mounted actualy helps with the CG, since my motor is so light... I cant remember exactly, but I think this motor setup is about 2 ounces lighter than the stock brushed motor + mount....


You can see the down and right thrust in this pic, there is a lot of it, but it flies great....
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Old Apr 18, 2011, 07:52 AM
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firewall

For those of use that fabricated the aluminium motor mounts, looks like multiplex agrees with the need to do this for a brushless upgrade.
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