FT Mini Guinea Build

[BridgeInspector]

The entire mount comes unglued. The pod stays in the mount really well. Its the mount that is the issue. I am going to pull them off with a heat gun and redo them I think. May add some gorilla glue in there as well for good measure.

Are you taping with extreme packing tape (or at least packing tape) across the front of the firewall too? Just like on the full size pods the tape helps hold the firewall on, or at the least catch it if it comes loose.

You can also use some extra hot glue into the inside of the firewall/pod connection may help

 

[nevenelestate]

The entire mount comes unglued. The pod stays in the mount really well. Its the mount that is the issue. I am going to pull them off with a heat gun and redo them I think. May add some gorilla glue in there as well for good measure.

Are you taping with extreme packing tape (or at least packing tape) across the front of the firewall too? Just like on the full size pods the tape helps hold the firewall on, or at the least catch it if it comes loose.
You can also use some extra hot glue into the inside of the firewall/pod connection may help

BI, I think he means the whole nacelle pod, the part that is glued to the wing, then you glue the "motor pod" into it. As I mentioned, I have had hot glue break loose from tape, but that should not happen with the paper(with DTFB)

Is this the part you are referring to DanTheMan?

 

[dantheman]

Sorry I was not explaining myself well. Yes, that is the part.

 

[BridgeInspector]

oh the nacelle is coming off. Ok now I think we have it. Do you have tape on the wing or nacelle, as nevenelestate mentioned?

 

[CrossedUpChris]

I'm knocking up a mini guinea at the moment. The smallest batteries I have are zippy compact 1600 4s. I have some small 1900kv motors so I was thinking the extra cell count would be beneficial. Do you guys think the mini can handle the weight of that battery?

 

[BridgeInspector]

I'm knocking up a mini guinea at the moment. The smallest batteries I have are zippy compact 1600 4s. I have some small 1900kv motors so I was thinking the extra cell count would be beneficial. Do you guys think the mini can handle the weight of that battery?

Sure, but it will effect the slow speed abilities as you will have to keep the speed up. Make sure you reinforce your wing inside at the joint and at the tips to avoid the wing folding under high speed maneuvers due to the weight.

Good luck!

 

[CrossedUpChris]

Thanks. I'm making the mini guinea after building a racer then realising that my flying space is not really big enough. Maybe I should get a small 3s as I don't really want another missile.

 

[nevenelestate]

I suggest going to Home Depot and buy one of their wooden yard sticks, it makes a GREAT wing spar.

 

[pakrat1022]

I've been following Nerdnic's idea, going to Lowes and buying the aluminium 3' strips for spars, sandwich them between the foam spar and never break another wing. works great

 

[CrossedUpChris]

Ok guys my guinea is good to go! All up weight with the battery is 720 grams. This is with some 4s 1000s I ordered especial. I hope this isnt too fat. That is with 1900 kv motors on a 4s though so it should fly maybe not that slow. I have used counter rotating 6x4.5 props that match the wheels beautifully. the motors can handle up to a 7x5 so I have room tonplay with.

I have blue arrow digital precision sub micro servos all round. They seem to have plenty of torque.

It's been an enjoyable build but it took me quite a while as was using parts that I bought a while ago and they were hiding around the house.

I have mounted the firewalls directly onto the nacelles as I don't really like power pods.

I can't fly it just yet as the whether is awful but I'll post about the maiden.

I haven't hooked up a door mechanism yet as I want to make sure it flies before I put anymore time into it. Also I used some wood from the local DIY shop for spars.

 

[CrossedUpChris]

It flies!! i just came back from a successful flight in the dying minutes of daylight. this wasnt the maiden however :black_eyed:

The maiden ended very quickly when the plane took off, barrel rolled a few times then faceplanted into the grass. luckily i had made it of the tarmac!

I thought it was maybe just too heavy and overpowered but when i got it home i discovered i had the ailerons the wrong way round... oops.

i had already printed off plans for an f22 to try and build by the morning when i realised the damage was not terminal.

a few squirts of hot glue later and she was good to go.

It was a little bit silly to go out so late. I had my car headlights on as i drove to the take of site, but I didn't want to have finished the day with a smash. After checking the control surfaces thouroughly multiple times and then once more, i rolled out for a take off.

Wow this thing flies nice. 3 clicks of right aileron was all the trim it needed. i don't know if it is the weight i have in it, the power, the airframe or all 3. but it flies so scale. i've never flown anything like it. - well maybe my racer but i was too terrified to really think about that as it thundered along.

i didnt go anywhere near full throttle. i must have been cruising around at less than half.

anyway, after doing a couple of circuits and trimming it out nice it was really getting dark so i brought it in for a landing. i tried to bring it in slow but nevertheless it rolled for about 25 meters! good job i touched down at the far end of the tarmac. ive never flown anything with landing gear before so this was all new to me.

anyway, last night i installed a servo operated hatch too. you can see it in the test video below.

I just tested in the house by holding the tail and aiming the plane upwards. it will try and climb out of my hands at half thottle! gonna be a fun flight tomorrow!

below is a little video just showcasing the plane and the motorised cargo hold. (pre nose dive)

https://www.youtube.com/watch?v=WIpb51ooeGY

 

[CrossedUpChris]

I love this plane. Ran about 10 batteries through it today. From 1000mah to 1600 in 3 and 4s. Can't really feel the extra weight.

The unlimited vertical, speed and acceleration is great. Theneed back it off a toutch and it flies so scale.

Had some parachute drops today as well.

Anyone thinking of going slightly heavier for a powerful build on this plane should do it. I've had so much fun

 

[nevenelestate]

This weekend I started my next mini guinea, not even sure how many of these I have made now. I want to have the MG to use for dropping things from the cargo area so the first thing I did was cut the fuselage parts and work on a cargo door openint mechanism. I wanted to try a dual door system using one servo so I did a quick bit of fiddling and came up with the design below.

With the straight linkage the servo couldn't really push the doors closed enough. Also with the straight arm, one door opened a bit more than the other, at full open.

I modified the linkage arm to the shape below and got better results. This allowed the servo to apply more force to the doors in closed position, the red dot being the pivot point, as well as making the movement of the two doors more uniform. The issue I had was getting the push rod lengths right. Due to the short length, and the small area to work in, it was hard to get a z-bend on both ends at the exact lengths needed, one door wouldn't quite close all the way.

I ended up scrapping the dual door design for this build, maybe on the next one.

I then built the bottom piece per the plans and used the same inner bay walls I had cut for the above project. With the servo already located on the front wall I simply placed a control arm on the door and added a push rod with linkage stopper.

I setup my radio to have the door on the flaps channel, this gives me two open positions, closed, mid open and full open. I then mixed in Button I on my radio to fully open the door on push also.

 

[CrossedUpChris]

Looks nice. I'd like to rebuild my guinea at some point as it lools pretty beaten up after the maiden but for now I'm just going to fly it as it still flies nice.

The door system looks good. I put my control horn over to one side and it twists the door a bit wh3n it opens causing the paper to delaminate. I strengthened it with some things ply but I don't think it will last forever

 

[Craftydan]

Neven,

Cute hatch linkages. . . but there's a reason bombers have their bays very close to the aircraft's CG. Are you sure you want your drop bay to be that far aft? Sure, it's one thing to mount the hatch aft, load up whatever you want to drop on the CG then nose up and pop it out the back, but the bulkhead ensures whatever you drop remains on the tail . . . adding to tail weight all the way up . . . which will be missing on the way back down. Unless you're dropping glitter or streamers you're virtually guaranteeing you'll either be badly tail-heavy on the way up or badly nose-heavy on the way down.

 

[LooseBruce]

Ailerons

I have made the mistake of reversed controls more times than I care to admit.
I no longer just wiggle the control surfaces before each flight. It only takes a second to actually think about and check the DIRECTION of control surfaces.
Haven't had a problem (with reversed controls) since I developed this habit.
LooseBruce

 

[nevenelestate]

The door system looks good. I put my control horn over to one side and it twists the door a bit wh3n it opens causing the paper to delaminate. I strengthened it with some things ply but I don't think it will last forever

I suggest a hot glue reinforcement of the hinge line, I actually peel the paper back a little to get extra glue under there for even better hold.

Neven,
Cute hatch linkages. . . but there's a reason bombers have their bays very close to the aircraft's CG. Are you sure you want your drop bay to be that far aft? Sure, it's one thing to mount the hatch aft, load up whatever you want to drop on the CG then nose up and pop it out the back, but the bulkhead ensures whatever you drop remains on the tail . . . adding to tail weight all the way up . . . which will be missing on the way back down. Unless you're dropping glitter or streamers you're virtually guaranteeing you'll either be badly tail-heavy on the way up or badly nose-heavy on the way down.

I have built a few MGs now and haven't had any issues with the CG while dropping stuff. I usually just drop small parachute men, or a homemade chute with a 808 camera hanging below it. Not looking to drop a full soda can or anything. The MG is such a good flier that a small shift in CG, especially towards the nose, doesn't impact handling that much.

I did build a bomber-style bay, under CG on one of my Sea Duck prototypes http://forum.flitetest.com/showthre...lSpin-Sea-Duck&p=176204&viewfull=1#post176204. In the video you can see that I didn't have the geometry right so they didn't actually open up all the way.

 

[LooseBruce]

Bottom of wing flat?

Hi Flyers,
Is the bottom of the mini guinea wing flat?
My maiden did not go well. I am noticing that the trailing edge of the wing where it meets the fuselage actually tips the wing a little so that the flat portion of the wing does not sit flat on the top of the fuselage.
I have no wheels as I hand launch in a hay field.

When I hold the plane in my hand and advance the throttle the nose pushes down greatly. Do you think this could be normal?

This is not my 1st mini guinea. I didn't notice this in previous builds.
Any help will be appreciated.Thanks,
LooseBruce

 

[CrossedUpChris]

Hi Bruce

My wing does tip slightly forward like you describe. When you say, "did not go well", what exactly happened?

My MG is a bit of a tank but at about 35-55% throttle it cruises nice and straight any less and it will stat to lose altitude slightly, any more and it will climb. At full throttle it will pull up quite severley to the point where if i want to do a high speed pass, i take it up high, point it into a vertical nose dive and give it full beans so that it goes straight by the time it is passing.

I imagine that the motors being slightly below the wing level will cause the nose to pitch up under throttle, essentially leveling off the wing. I'm no expert though

 

[nevenelestate]

cut a notch in the trailing edge to allow the wing to sit flat.