??Centre of Gravity for Easy Glider??

[Jack_Chen]

To experienced glider fans, especially for Easy Glider owners, noob question on centre of gravity for the Multiplex Easy Glider Electric.

Usually I will refer to the manufacturer's specs for the Centre of gravity. The recommended centre of gravity for the Easy is 70mm from the LE along the wing root. I measured and mark it with a line.

It is somewhere on the cover of the wingspar.

I am using the stock motor and gear setup, HS-82MG servos instead of HS-81. Feather HS-55 for the wings. 2250 mAh 3s1p Lipos with a 25A Brushed ESC from Electrifly. Obviously the LiPo battery cannot fit into that tiny space for the stock battery. I carve into the foam to slot my LiPo in. The good news is, I haven't CA the fuse yet.

So I dry fit everything together with masking tape and the electronics the plane was nose heavy by about an inch. So I carve a bit more into the plane to push the battery back more. Still nose heavy. And so it goes along the battery slope until the end of the battery is barely 1 cm from the bottom fuselage surface. The best position I got to is nose heavy CG just at the wingspar cover opening (about 1.5 cm away). Now, I think I exhausted the option for battery shifting and am thinking of adding tail ballast to correct it. I already added that ball bearing behind.

Just to note, I got 8 LiPo batts and 7 of them are about same size/weight and all 2100~2250 mAh. So I can't change the battery.

Question 1. Is tail Ballast advisable? Although this plane can fly with quite some weight, RTF at 32 oz~910g and some flew even more at 36 oz~1020g and heavier.

Question 2. What should I use for tail ballast? Got some left over hideous plasticine from GWS kits.

Question 3. Any allowance on the CG point? Some forums I trawl through recommend instead an alternative CG 5mm in front. So I guess it's either 70mm from LE to 65mm from LE. Not much allowance.

[DL8698]

To experienced glider fans, especially for Easy Glider owners, noob question on centre of gravity for the Multiplex Easy Glider Electric.

Usually I will refer to the manufacturer's specs for the Centre of gravity. The recommended centre of gravity for the Easy is 70mm from the LE along the wing root. I measured and mark it with a line.

It is somewhere on the cover of the wingspar.

I am using the stock motor and gear setup, HS-82MG servos instead of HS-81. Feather HS-55 for the wings. 2250 mAh 3s1p Lipos with a 25A Brushed ESC from Electrifly. Obviously the LiPo battery cannot fit into that tiny space for the stock battery. I carve into the foam to slot my LiPo in. The good news is, I haven't CA the fuse yet.

So I dry fit everything together with masking tape and the electronics the plane was nose heavy by about an inch. So I carve a bit more into the plane to push the battery back more. Still nose heavy. And so it goes along the battery slope until the end of the battery is barely 1 cm from the bottom fuselage surface. The best position I got to is nose heavy CG just at the wingspar cover opening (about 1.5 cm away). Now, I think I exhausted the option for battery shifting and am thinking of adding tail ballast to correct it. I already added that ball bearing behind.

Just to note, I got 8 LiPo batts and 7 of them are about same size/weight and all 2100~2250 mAh. So I can't change the battery.

Question 1. Is tail Ballast advisable? Although this plane can fly with quite some weight, RTF at 32 oz~910g and some flew even more at 36 oz~1020g and heavier.

Question 2. What should I use for tail ballast? Got some left over hideous plasticine from GWS kits.

Question 3. Any allowance on the CG point? Some forums I trawl through recommend instead an alternative CG 5mm in front. So I guess it's either 70mm from LE to 65mm from LE. Not much allowance.

I'm not really so experience an Easy Glider. Recently lost my E Glider up a "plane eating tree" at the slope.

However, after about a couple of months of fooling around with my E G Electric, if I'm not mistaken the stock motor, which you are using, should use "2S" lipo, not "3S" lipo, (pls see http://plawner.net/4/easyglider/easyglider.html). This is also what my mentor told me when I built my E G under his guidance. Perhaps the "3S" is way too heavy resulting in "nose" heavy.

My E G was flown with the motor not installed and the weight substituted by 100 gm of lead (which was the weight of the motor). The balance was spot on the specified CG as per the instruction manual, ie at 70mm from the LE, which puts it just at the rear edge of the CF wing rod. On top of that, as advised by my mentor, I added approx 50gm of lead weight at the CG position (behind the battery compartment) for additional high wind penetration ability.

I was using the normal 4 NiCad cell pack which came with my Futaba Radio Control set.

My E G flew very well as such, so much so that I got so carried away throwing it around all over the sky, I finally lost sight of it behind the trees, and that was the end of it. Managed to retrieve the wings and the electronics but the fuselage is still up that tree, too high to retrieve!

Regarding the tail ballast (the provided steel ball), I did not use it as the above mentioned reviewer said it was not necessary. Trying to get the correct CG location on nose heavy plane by ever increasing tail weights does not sound advisable, as gliders are supposed to be light to maximise its thermalling, or soaring ability, up to a point. I believe the culprit here is the weight of the battery you're using. Try using a 2S lipo and see what happens.

Also if you're using masking tape to hold the plane together while balancing, be aware that due to "moment arm" effect, the same length of tape at the tail (far from the CG) can have much more effect on the CG location than for that same length of tape at nose (nearer to the CG). So that could throw everything out of whack when you finally glue the fuse together and discard the tapes.

[Jack_Chen]

Thanks to DL8698 for your sharing. I didn't want the stock motor but it came with the plane. I wanted a brushless replacement to just pop it in but unable to find any suitable locally. Not sure where to get, what to get.

Even at NTC that day when I went to ask, the lady forever only shaking her head when I ask got this or not, got that or not, Not in stock, don't have. What to do?

Should I get some 2S Lipos? Which will cost me at most $100+ (for 2 lah).

Or I look to dedicated glider websites for a 3S LIPO replacement BL motor?

Any EZ expert can recommend a locally available BL motor (can use with 3s Lipo) that I can just pop into the gearbox, together with the recommended spinner, prop adapter and folding prop?

I am frustrated but this hobby take time and patience . I need to take more deep breaths , meditate on this for a while .

Sorry for all the excess smileys.

[mave]

NTC has this direct drop-in brushless replacement for easy glider. you do not need any mod for this replacement.

But i think it is a bit expensive.

Thanks to DL8698 for your sharing. I didn't want the stock motor but it came with the plane. I wanted a brushless replacement to just pop it in but unable to find any suitable locally. Not sure where to get, what to get.

Even at NTC that day when I went to ask, the lady forever only shaking her head when I ask got this or not, got that or not, Not in stock, don't have. What to do?

Should I get some 2S Lipos? Which will cost me at most $100+ (for 2 lah).

Or I look to dedicated glider websites for a 3S LIPO replacement BL motor?

Any EZ expert can recommend a locally available BL motor (can use with 3s Lipo) that I can just pop into the gearbox, together with the recommended spinner, prop adapter and folding prop?

I am frustrated but this hobby take time and patience . I need to take more deep breaths , meditate on this for a while .

Sorry for all the excess smileys.

[Jack_Chen]

after mediation and looking at the brushless 'combos' replacement prices . It's easier to just get a large capacity 2S Lipo to power the stock brush motor. If burnt out, no biggie . Just get a few more brushed motors. Pretty affordable compared to the brushless .

[DL8698]

Looking at your signature, seems you have problem balancing your other planes too (your P51, Beaver). Sure you're doing the balancing procedure correctly? I just use the tip of one finger each hand, place at specified CG location under wing, just outboard of the fuselage, and lift. If the plane is lifted up in horizontal orientation, the CG location is correct. And be sure to do in still air, not under a ceiling fan, for example.

[Jack_Chen]

The GWS Beaver was my first plane ever. Let just say that I supposed the plane flies well with the stock items and in good building hands. I do a lot of guesswork and the equipment I had, OBL, 40A esc, lipo batt, all not the recommended standard materials.

I didn't build the P-51 Mustang. Got it cheap off another forumer. Just want to try fly it at a whim.

The Tiger Moth was sweet. balanced at the correct CG. Was doing nice turns and a slow figure 8 before coming down for a grass landing . It was slightly banking right about 1.5 feet above ground while facing me. Had a disoriented moment.

--- What I should have done, nudge left, level off, ease back on throttle, pull a little elevator to flare for landing ----

What I did, nudge right, wing kissed the ground, left wing swung around like a clumsy cartwheel and the fuse broke into 2 halves.

So I am guessing I didn't do the math properly. And the 180g lipo didn't help. It flew because of the motor strength. Got a bunch of 2000+ lipos, should have kept them for the helis. Foam flyers, I realised now, goes for light loads. Breezy setups. Very sian. Got motors that are suited for heavy planes, like .15 to .32. Got Batts that are also suited to heavy planes/helis/large sailplanes. Guess I was too greedy, capacity means longer flight.

well, back to research again. By the way, anyone did spreadsheets of hobbyshops/parts/pricing? I did a simple one for my lipo batt pricing research. If you put it in a pivot chart, wah, best part at best price can be matched.

Yes, now I got a CG issue with the Easy Glider. Because I know how to mark and gauge the CG, I have realised the problem.

On the other hand, sidetracked, got a Easy Glider lookalike at Jet known as Easy Fly. Accepts a OBL straight into the nose, not sure got mod or not. Sian. The motor option for that one seems easier.

[Jack_Chen]

CG can solve, quite ok.

well, after mulling around forum threads both here and elsewhere.

Bought some 2S lipos, pretty good deal if you buy 2 at Jethobby.

To correct CG, there are stick on weights in quarter ounce or about 7gram sizes available at NTC. Produced by Great Planes, I think, if required, I will stick some to make sure the CG is around there.

On the other hand, I got the Easy Fly off JetHobby as well to see how they do the OBL mount. They have this plastic looking or fibreglass firewall piece wedged by the fuse which you just attached your OBL to. The jethobby combo motor is too big actually, so the boss recommended one with diameter slightly smaller. He also recommends a 11x6~11x8 folder prop though I have to go down to NTC to get it.

while I was there, he sells those lipo batts for TX but when I asked him which is suitable for Hitec Optic 6, he don't know. I got the tx batt off another forumer second hand. this is what I found out.

1. The DN Power Tx Lipo fits nicely into the Hitec Optic 6.
2. Before plugging in, check the polarity. If you had the NimH batt previously, look at the wires, check where is the red/black and then when you plug in the lipo, use the same polarity/colour. I think it's the JR connector, the small white one.
It plugs in sweet, you may want to tape it to secure it. OR, you can get another connector or even cut off the old one and solder on. Anyway, I plug it in, turn on the tx and sweet voltage 12.4v comes on.

Lesson learnt from overhearing Uncle Mike in conversation while at Rotor. Apparently Uncle Mike charged his lipo until it became hot, I guess he overdid it. And when he used it with his tx, it got fried. Therefore nowadays he adviced customers, if required, just buy another Nimh.

As a lesson learnt, possibly when I charge my own Lipo, I will charge until about 12v thereabouts . No point going 12.4v when it's not for a plane or heli but the tx.

[DL8698]

Lesson learnt from overhearing Uncle Mike in conversation while at Rotor. Apparently Uncle Mike charged his lipo until it became hot, I guess he overdid it. And when he used it with his tx, it got fried. Therefore nowadays he adviced customers, if required, just buy another Nimh.

As a lesson learnt, possibly when I charge my own Lipo, I will charge until about 12v thereabouts . No point going 12.4v when it's not for a plane or heli but the tx.

I wonder how Uncle Mike and you are charging your TX Lipo batteries? Do you charge "through" the TX using the supplied power supply that the Radio set came with, as if you were charging your original NiMH batteries?

Is this advisable? Charging through the TX is "non-stop" if I am not mistaken. That is, the TX will NOT cut the charging current when the Lipo reaches its full charge point, and you may end up overcharging the Lipo which is not advisable and could possibly cause your Lipo to catch fire.

I just bought a Lipo for my Futaba TX and have not yet set it up into my TX but I intend to do my charging strictly via an external Lipo battery charger through the Balancing charge port on the battery. To balance charge may not be so critical on Lipo used for TX but I think it is more convenient than pulling out the power plug from the TX every time I need to charge the battery.

[Jack_Chen]

Dude, it's a LiPo battery. use only chargers for lipos to charge. I read about LiPos and the safety requirements. I was given a lecture on LiPos when I bought my first one. Not to mention lipo safety is a common sticky thread in RC forums. The most sian thing about lipos is I have to be around when they are charging.

Just to note: At last count I now own 11 lipo batts. 7 x 3S-2000+mah mostly for helis and large planes, 1 x 3S-1300mah polyquest (my first). 2 x 2S-2100mAh courtesy of Easy Glider and Brushed motor. The tx lipo is my 12th Lipo batt. A lot of second hand lipos gotten during all-in deals.

I have seen how the batt reacts when you overcharge it in Youtube. The bag expands, vents, then the aluminium starts to ignite and burn. Aluminium is pretty dangerous. That was the aluminium coat burning with a bright orange glow on the Hindenburg. Powdered aluminium is used in solid fuel boosters. Not to mention the large electricity discharge when the batt goes funky.

If you ask me, I will use the Align lipo balancer-charger I got from Rotor to charge the Tx batt which comes with that red plug for 2s batts.

As for how Uncle Mike did it, I don't know, I overheard him in a conversation. Someone was buying a 9channel tx, I think JR. The price quoted was either close to 1K or 1K+. The customer asked about Lipo TX batts. Mike spoke of his experience. The guy knew more about lipos and also offered that no Lipos should go beyond 12.6v. Since it's conversation between 2 oldbirds, I just kept quiet and listen to their wisdom lah.

What I do know after that conversation is Uncle Mike said he preferred to just buy another Nimh for his tx and showed the guy the Nimh they carry. Around $60+ I think.

The good news is I got the tx lipo second hand at $40 which is a pretty good deal I reckon. Works fine and pretty longlasting. I used to turn on the tx after an overnight charge to troubleshoot settings and test the servos and angles of incidence after a build. Just barely 10~15minutes later, you see the voltage on the LCD start to drop. I plan to fly gliders which hopefully will last a lazy afternoon of use.

Anyway, when not using the tx, unplug the batt and store it properly like the rest of the lipos.

[simonwoo]

I don't know why, but this thread always gives me an uncomfortable feeling haha

You get a lipo batt for your TX, you charge it like you would charge all your other lipo batts. No cell is supposed to be charged beyond 4.2V, yep. Your charger should take care of that. If you are worried about your 1xTX batt, then I think you should be worrying about your other 11xbatts as well.

I'm not sure where all this talk about overheating and overcharging and explosion is coming from.

[Jack_Chen]

Finally Maiden.

Hi all, maiden my EZ on Saturday. Thanks to Uncle Rosman for guiding my first few minutes with the glider. Also thanks to him for giving me a lift home after my sandal got stuck up the tree while we were trying to get my glider down.

EZ Glider flies very well. Control and response is good. The wing span is big so it gets blown off course easily when banking into the wind. Plus the stock motor is not able to run against the wind. That pretty much summarized how it got up the tree.

Next time, I must move more to the centre of the open space. Anyway, thanks to all the enthusiastic RC flyers who were assisting me. No joke being up in the tree until late evening.

Came back the next day with 5 bamboo poles and a roll of nylon rope to lash the poles together. Climb halfway up the tree and used the poles to nudge the glider loose. Glider came down in a spiral because the wing came loose and was hanging by the wing spar rod.

Anyway, assessment of damage. Tail part broke loose. Rudder ripped clean off but recovered. Wings came apart when I got it off the tree but its a 2 piece wing in the first place, it only came loose. Except for the right wing aileron, a small square broke off but also recovered. Mostly some good tape will do the trick. Have to inspect the 2S lipo though. Since I can't unplug it and I have to turn off the tx, the lipo being running throughout the night.

[plug&fly]

Hey man

Glad to see that both pilot and glider came back to earth safely, just slight damage on the glider and some bruised ego on the pilot. Can't wait to see it flying again.