SackOHammers

Gludobber, like woodbender said, take a look at post #1396.

After Doc and other guys tested and played, thats a working combination they came up with. I think they played with Torque as well, I don't remember.
If you go to adchobbystore.com you can find most of the parts there.

Fliprob17

Sorry for the delay.

Ya, just stick with the defaults for 3s. It is ready to rock right out of the box. Just verify that the brake is off, make sure the prop. continues to spin once you kill the throttle. Programming is not that bad, you just have to listen for beeps, that's the only bummer.

Fliprob17

There are a few brands of LiPo's that you can get away with saving a little $$'s on and not sacrificing performance. Personally, I only fly Thunder Power and have never had a problem. They flat-out just perform for me. We are just now looking at a slightly lower pricepoint of LiPo's to carry in the store. Around $55 or so for a 20C 2200mah 3s, should be testing them this week. If the performance is comparable, we will be carrying them. But still, when it comes down to it, I will always go back to Thunder Power when I really want the highest level of performance.

Motors and esc's - The Torque and Airboss stuff is really solid, again all I am flying right now, a tad cheaper than E-Flite, shoot me a PM or E-Mail if you are interested in a Motor & ESC combo. Castle Creations stuff is pretty bulletproof as well, but you will pay for it.

altamash_rah

Woohooo, I have been eyeing the Mini Pulse XT for awhile now and I finally got it today!!!! I wanted to be up in the air faster so I got the PNP version, Seen alot of complaints about the servos, ESC, etc.. that comes with the PNP, so i had a few questions I hope someone would be kind of enough to answer

1) so my first question is anyone have any experiences with the PNP, good and bad???

I am going to change the 22A stock ESC with my PZ t28 trojan 25 A ESC pro, maybe it will be a good preventative mod

2) Anyone get that Yellow slip of paper with their PNP version from E flite saying that it would be a good idea to add a seperate BEC in the unit?? If so, what is a good hassle free BEC to get??

3) any other preventative mods that you could suggest would be great!!

I will maiden this bad boy once the weather becomes a little dryer, right now it is wet in good ol Houston, TX oh well...............I will post some more pics and vids soon

bertsirkin

I think I had a servo go on my PNP. on the 3rd or 4th flight it fllew fine for a minute or do and then took a dive and hit the ground on the wheels. The only damage was to the wheels which basically destroyed the fusalage. One of the servos was "stuck" in a position a full 90 degrees from the midpont.

I added the "ParkBEC" (http://www.dimensionengineering.com/ParkBEC.htm) - before I few it, but kept the original ESC. It's pretty stupid that they sell a plane and then put that little yellow slip in there telling you it's basically no good the way they sell it!

As everyone says, the wheels are the weekest point. I really need to do something about it. I have 2 MPXTs - one with the stock (PNP) engine, the other with the 480. I almost like the stock engine better. The 480 is too fast (for me)!

bert

Fliprob17

If you will be swapping out the PNP ESC for the 25amp Pro Brushless you should not need an additional BEC. The 25amp Pro is a much better unit than the PNP version.

I would highly recommend reinforcing all of the stress/wood joints with thin CA and/or 30 minute epoxy. Landing gear plate and blind nuts, all seams at the firewall and motor box, etc. and check the elevator joiner wire to make sure it is completely secure. The one issue that seems to pop up is there is not enough "factory glue" applied to all seams throughout the kit. If you will be going without the wheel pants, nylon bolts would be a good bet, but with the extra reinforcement applied in and around the landing gear plate, if you leave the wheel pants on you should be ok. Plus if the nylon bolts break, the wheel pants will put a hole in the wing covering.

Welcome to the club, good luck!!!

Toker41

I have been flying the PnP version of the MUS for a couple years. Never had a problem with it. I took all the electronics from another PnP MUS, and put them in the Mini Pulse. Ended up switching the motor to a 480, but still using the PnP ESC, and servos. Just crossed my mind that the ESC could be the reason that I'm not getting the speed from the 480 that I feel I should be. Servos are not the best, but they do just fine.

altamash_rah

Thanks for the tips !! I will definitrly start working on reinforcing the critical areas

I will be using the parkzone 1800mah 11.1 V LIPO from the PZ trojan in the pulse, I also purchased a 2200 mah 11.1 PZ battery for the trojan, are there any electronic issues I should be concerned about before I start using the 2200mah powerful battery?? (electricity/electronics is not a particular area of study I know much about..please forgive the noob questions!)

Does using a more powerful battery place any types of loads on the ESC???

Also, What is the best way to check the CG, the current method I use is not that precise at all, I basically lift the plane with two finger tips at both ends of the plane at the recommended CG for the pulse, I know there are machines out there that test for CG, but is there a cheaper method to do this???

Thanks for the help guys, I really appreciate it!!

woodbender

[/quote]
Also, What is the best way to check the CG, the current method I use is not that precise at all, I basically lift the plane with two finger tips at both ends of the plane at the recommended CG for the pulse, I know there are machines out there that test for CG, but is there a cheaper method to do this???
[/quote]

Doc Austin suggested a way to do this that works very well for me. I made a balancing block using two dowels mounted on a wooden block. The dowels are far enough apart to clear the fuse and tall enough to allow the plane to balance upside down.. yes, that's upside down.

I sharpened the dowels to dull knife points so they don't interfere with the plane's motion. I marked the measurement on the top of the wing, inverted the plane, moved the battery around until it balanced on its marks.

This particular plane seems very touchy if it's not balanced just right and very forgiving if it's just right. I'm having very good luck with it balanced just where the factory says.

bertsirkin

I'm not sure why, but I have a very difficult time determining if the MPXT is balanced. I've been balancing it righ-side up and no matter where I test it, it seems to lean forward AND back. Do you test it upside-down??

bert

woodbender

Yup, upside down, Bert.

There's a logic to it. The actual CG is different from the fore/aft balance point. The CG is up from the wing root I'd guess somewhere around the top of the blue stripe. Since the CG is UP from the bottom of the wing, it stands to reason the plane won't sit still even if perfectly balanced right side up on supports since the CG is above the supports. Upside down, the CG is below the supports so the plane, once on the balance point, will sit there very nicely. You can tip it one way or the other and it returns to level just like magic. Hat's off to Doc Austin for suggesting this whole notion.

Bottom line, this plane seems temperamental until you do all of the stuff Doc and others suggest; power up, reinforce the landing gear, get the throws just right, balance, etc.. it all seems trivial, but once it's really set up, the plane is simply amazing to fly. It's fast, maneuverable, lands like a dream and quite predicable.

bertsirkin

Hi Lon,

Thanks for the great explanation. I've only been flying since last September and haven't had a lot of time to do it here in Connecticut. The flying field here has very poor access and is impossible to get to if there's snow on the ground.

But, as you say, it's the little things (that aren't so little) that count!

I'm going to check the CG now!

thanks,
bert

ZX11

I put the eflite 450BL on my PNP and run the rest stock. I have seen two other planes with the PNP motors and they seem to run well. The 22A ESC's onboard BEC works fine for me. I take off the gear and hand launch in tall grass. Otherwise, I use nylon screws for the gear.

SackOHammers

Yeah folks, a CG "machine" is basically a piece of plywood with two holes drilled in it... then you put two sticks in the holes.
Build one, you will be rewarded with better flying planes.
Here is the guide I used to make one:
http://supercubclub.proboards78.com/...ead=1170341301

woodbender

Seeing the photos in the link SackOHammers posted, it reminded me that a high wing plane (Piper Cub type) will have a CG below the wing so a right side up balancing method works fine. A low wing plane (Mini Pulse XT type) will have the cg above the wing so this type is easier to balance upside down.

It's worth noting, that the term CG is often used in place of the more accurate (in my opinion) fore/aft balance point. These two points are different, but only in a technical sense.

Textanker

I just maidened mine yesterday morning. It currently has a Hacker 400 (low power, I know, but it's what I had), a 2100 MAH pack, and a 10x4.7 prop. I balanced it at the recommended point, but it seems very "twitchy". I have lots of glo-powered flight experience, but this thing isn't giving me any real confidence. Can you guys give me some setup tips? I can't really get anything from the number of posts. I am curious if it migh be the CG, and if so, what is ya'll's method for moving it, since my Lipo pack can't really move much. Thanks!

altamash_rah

MPXT-PNP issues

Alright, so let me provide an update on my new MPXT - PNP...

I bought the mini pulse PNP a few days ago and am in the process of prepping it for flight, (reinforcing joints, checking cg, checking all servo throws etc...), during my testing of the motor, i noticed that the motor was twitching/pulsing at certain low speed throttles percentages around 15-20%. So i took the cowl off and inspected the 3 wires, and lo and behold!!!..........the black wire had not been soldered on correctly, as you can tell from the pictures, their is a clean break of the wire and the solder!!!!!! I have also noticed that the top panel of the motor box has a funny angle that makes the motor lean to the right a slight bit,

the motor box issue is not as big as the issue with the motor wire, i just wanted to let the pnp users know what other issues to be aware off, off to my LHS I go!!!

S.C.C.

Thats correct, it's your thrust line.

bertsirkin

It';s kind of strange, especially the first time you notice it, but the prop is supposed to be angled slightly down and to the left (when looking at it from the front). I work at a small airport and when I first noticed this on my RC planes, I took a look at the real small planes at the airport and they had the same skew, except for the fact that the real planes props turn in the opposite direction so they're skewed to the right instead of the left.

The way it was explained to me was that the prop actually turns faster on the down-swing than on the up-swing. That skew to the side compensate for this.

bert

altamash_rah

Thanks for the insight bert!! i really did not know that at all, and i feel much better knowing that it may be something that is part of the design of the MPXT rather then an error in cutting the front motor box plate.

Well, my LHS replaced my motor with a brand new one, and I maidened my MPXT today so let me give a visual description of the flight since i have no video to show

Here is my setup

TX - DX6 Spektrum parklflyer
RX - AR6000
Servos - Stock PNP, eflite 9 gram (4)
Motor - Stock Eflite 450 BL
ESC - Stock eflite 22a ESC

I flew at the local fortbend rc air field, you can see an aerial picture of the field in the attatchments
No clouds, bright and sunny day
wind:12-15mph
-it was a little windy but i figured it was the best way to learn plus the wind will help with slowing the plane down for landing

So I taxied the MP out to the runway, raised the throttle up to about 70% and she started to float up, the strong headwind was making the MP look like a helicopter so i gave it 100% throttle to fight the wind, i banked to the right and started heading the opposite direction....that wind made the little MP fly like a jet!!, made about 3-4 laps and attempted a roll, the plane rolled very nicely!
So now after a few minutes I was satisfied that the plane flew well and wanted to bring it in for a few minor adjustments,
the fear of crashing was creeping in now.........strong head winds plus beautiful new plane could mean disaster
I lined her up on the run way and about 15 feet up from the runway, i cut the throttle to about 20 percent, she started to float down exactly the way Eflite shows in their videos!!, cut throttle down to about 5-10% and she didnt show any signs of stalling, she floated right on in and touch softly on the runway!!!

Final thoughts
Thanks to Doc Austin for the explanation of testing the CG on the plane while it is upside down, I did that and feel that it was one of the big contributors in making sure the plane flies well. It was a great maiden flight and the plane behaves exactly the way I wanted it too, Initially I had setup up the MP using my 4 channel 72mhz TX system with a Berg mini receiver, I noticed during testing that the throttle and servos responses were a bit sluggish, I decided I would use my new DX6 TX, I used the ar6000 RX with the dx6 and noticed a great improvement in throttle and servos response!! I highly recommend this DX6 or the new DX7 remotes for this plane or any other airplanes, i really feel it made a big difference! I will have video of my flight next time.
The MPXT is a great step up from an aileron trainer, this is how i progressed:

1) PZ J3-Cub (3 channel system with BL motor)
2) PZ T-28 Trojan (4 Channel system....great way to learn how to use ailerons!!)
3) Eflite Mini Pulse XT-PNP

Thanks to all the people who contributed helpful information in this thread, I think my first maiden would have been quite different if it wasnt for the useful information i found here! happy flying!

GoldKraft

Good job altamash _rah ! Nice looking facility to fly at too !

bertsirkin

Awesome flying field and it sounds like a great first flight!!

I'm still having some stability problems with mine, but I haven't checked the CG the way it was described here yet. I have to wait till the snow melts before I can fly again.

bert

altamash_rah

Thanks gold!




yea, check the cg while its upside down

you could attatch some skis and fly

SackOHammers

Yep, balance her upside down because you're closer to CG when you balance upside down. I balance mine right on the spar in the wing. (that is the cross piece of balsa in the wing that runs the length of the wing)

If your plane is twitchy... well... thats because this plane can respond very quickly. To start with, put your plane on lower rates... only allow 75% of throw travel until you get used to the plane. But what helps even more is "exponential". I use a DX7.. but basically any programmable radio will let you use expo. I put mine at 25% (if you're using Futaba then that means -25%). Expo makes it so when you're moving the sticks near the center.. you have to move them farther to get the control surfaces to react... but as you get the stick towards the edge, then it moves the control surfaces more. It helps make things less twitchy and can certainly be great when landing.

Also, some folks flip their switches to low rates when taking off and landing, but switch to high rates during the flight.... something to consider.

I lucked out on my plane when I built it... I put it together, and when I put in my 2200 mah battery and put it on the CG machine... I didn't have to do anything... just make sure my battery sat 1/8 inch back (from its forward most position). When I flew it... I didn't have to give any trim at all.

Play with the to get it right CG, THEN trim it out.

altamash_rah

Yea, the programmable radios with the ability to set throw rates is a great help, i do my take-offs and landings at 100% throws and my landings at 70% elevator and aileron

I have not messed with the expos yet but it seems like a great tool,

i have the dx6 which has that function as well, so i will probably give it a try, so you say 25% is good??? on both elevator and aileron???