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Aug 18, 2019, 07:33 PM
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uncookedlentil's Avatar
Quote:
Originally Posted by Woodbender
When I was rebuilding mine, I cobbled all the parts together with masking tape several times.

Doing this, I was able to check the over-all weight and c/g.

Since I had an AUW goal, adding weight to get the c/g right was not an option. This notion led to LOTS of other mods like taking length out of the front end of the fuse.

I lost count on how many times I mocked the pieces up before I got both the weight and c/g where I wanted it.

Regarding props:

It really bugged me that the prop did not fold properly.

The culprit, IMHO, is the length (width) of the yoke.

It's too short to allow the prop blades to fold along side the fuse.

I wound up fabricating a new yoke which isn't perfect by any stretch, but at least it at allows the prop to fold like I wanted it to.
I sanded the fuse until the prop lay flat when folded.
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Aug 19, 2019, 12:50 PM
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Markran's Avatar
I just ordered a U-Glider kit! Very excited to finally get a lighter, floatier glider.

I'm definitely going to do the mod for aileron servos in the wing and I'm also going to try to rig a way for the wings and tail feathers to separate again for travel. Could someone please recommend engine, ESC and servos that you like for this plane? I'm looking for decent performance and durability more than cheapest price and I need parts available in the U.S. from a vendor like AMain, Amazon or the U.S. warehouses of HobbyKing or Banggood. Thanks!
Aug 19, 2019, 02:18 PM
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I run some Turnigy 3.7g as ailerons, like them allot. Stock motor and esc - works but dont like hard wind.
Aug 20, 2019, 06:26 PM
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Markran's Avatar
Quote:
Originally Posted by Woodbender
When I was rebuilding mine, I cobbled all the parts together with masking tape several times.

Doing this, I was able to check the over-all weight and c/g.

Woodbender,


I've been following your posts about your cool ultra-light build. My U-Glider kit is on the way and I'm ordering parts. I'd like to target an ultra-light build similar to yours and had some questions.

1. What diameter of carbon fiber rod did you use for your new "spine"?



2. Do you remember the diameter of the alumimum you used?



3. I found the motor you linked to (BTW your AliExpress link died but I looked up the AliExpress product code from the URL). For others the motor that Woodbender linked is a Sunnysky R1408. Did you get the 3200kv or 3600kv version?

4. I can't find that motor in stock in the U.S. now and am wondering if you could explain how and why you chose it? Sorry, I don't know a lot about motors. I'm guessing that the higher KV than stock is because you're running it on 2S and that reduces the KV down from 3200 back to the ballpark of stock? Since my glider is on the way from a U.S. warehouse, I'd like to source a different motor that's in stock in the U.S. Any advice on how to pick one?

Thanks,


- Mark
Aug 20, 2019, 07:19 PM
pull up -- PULL UP!!!
If you're thinking ultra-lite you might be interested in what I'm working on for weight savings on a 3D foamy. Instead of a conventional esc I picked up a multirotor esc that weighs nothing. Okay, it weighs 1.5g, almost nothing. That doesn't include wires, connectors or a bec.

I'm running with no bec -- 2S direct to all components. The rx is rated up to 10V, and the servos are rated up to 7.2V. They will be slightly overstressed -- so be it. People say it works. If you search ebay for 7.2V micro servos, you'll find some 3 and 4g available. Mine are 5.6g. I'm also using minimum wire lengths and direct solder in place of connectors.

Plane is not together yet, but I already power tested all the electronics -- works great on a test stand. We'll see.
Aug 20, 2019, 08:15 PM
Is it coming or going??
Woodbender's Avatar
Hi Markran,

For the 'spine' I used the square carbon rod that came with the glider.

For electronics, I'd go with what hard line suggests.

hard line could you post a link to that esc please?

As for aluminum tubes, I just bought several sizes making sure they would 'telescope.'

Believe me I know less about motors than you do. Go with whatever hard line suggests.
Aug 20, 2019, 08:27 PM
pull up -- PULL UP!!!
The one I actually bought isn't listed any longer. But this appears to be the same (or very similar) item except it has the wires installed. And heat shrink tubing which the other did not. Just bought two more since it seems to be working out.

https://www.ebay.com/itm/Rctimer-Sup...ty!93555!US!-1

BTW, it says it's from RCTimer. When I looked there I didn't see the wired version, but this one looks exactly like mine. But I paid way less on ebay. Who knows? Oh and it says the chip version weighs 1.8g not 1.5. I lied.

http://www.rctimer.com/?product-1320.html
Aug 20, 2019, 08:45 PM
Registered User
Markran's Avatar
Quote:
Originally Posted by hard line
The one I actually bought isn't listed any longer. But this appears to be the same (or very similar) item except it has the wires installed. And heat shrink tubing which the other did not. Just bought two more since it seems to be working out.

https://www.ebay.com/itm/Rctimer-Sup...ty!93555!US!-1

BTW, it says it's from RCTimer. When I looked there I didn't see the wired version, but this one looks exactly like mine. But I paid way less on ebay. Who knows? Oh and it says the chip version weighs 1.8g not 1.5. I lied.

http://www.rctimer.com/?product-1320.html

Hard Line,


Thanks for the tip on the ESC. It looks good. What motor would you suggest?

Edit to Add: I looked into 7.2v micro servos. The ones listed on EBay as 7.2v and 4.3g in their headline description actually say 6.0v and 7g "actual weight" in the spec table. This is identical regardless of the reseller. Since these are no-name generics only available direct from China (no U.S. sellers), I'm going to assume the specs may be less than accurate.

Are the servos you have the Turnigy TGY-D56MG? Those look ideal but appear to be out of stock everywhere at the moment. I think it's a cool idea to get these but it'll also delay my build to wait for out of stock parts... I may just build it with standard parts and look at the ultra-light build as an upgrade.
Last edited by Markran; Aug 20, 2019 at 09:23 PM.
Aug 20, 2019, 10:02 PM
Is it coming or going??
Woodbender's Avatar
I used these servos. Sure are spendy (they cost more than the plane!!), but smooth and powerful
Aug 21, 2019, 10:53 AM
pull up -- PULL UP!!!
Sorry, I don't have a motor to suggest. I love my SunnySky 2204/1450kv & 1800kv and use them for all my small planes. But too fat for a U-Glider. I'm still using what came with it. whatever that is.

These are the servos I had in mind. I would have to test them some before I trusted them. No risk trying them in my 3D plane. For some reason it seems to fall out of the sky on a regular basis anyway. I didn't see any mention of other than 7.2V (maybe I missed it.) The discrepancy in weight I believe is claimed weight is bare servo and actual weight is with wires and connectors. Not recommending these particular servos -- just what I would try. Quality probably sucks, but as long as it works...

https://www.ebay.com/itm/Mini-4-3g-M...0AAOSwxMRbnMo5

Woodbender, those look like nice servos, but I'm guessing low voltage from the write up. I'm barely okay with using 7.2V servos with the opto esc.
Last edited by hard line; Aug 21, 2019 at 11:04 AM.
Aug 24, 2019, 01:19 AM
Registered User
I used HXT 500 through out mine, including in the wing foe ailerons. It puts so little loading on them they are still fine after many hours.
The stock motor with a 450MaH 3S battery will go vertical no problem, No heat problem as the thing is gliding more than motoring.

In fact one of the hardest things I had to do was get some washers behind the motor mount to give some down thrust to stop it trying to loop if given full throttle. Not as dextrous approaching my 80Th birthday as I was.
Aug 24, 2019, 09:24 AM
pull up -- PULL UP!!!
Update on my 2S-direct plan. One of the 7.2V servos failed. So out of caution I replaced the opto-esc with a small 12A esc/bec for now, and ordered a 1.5g Buck voltage regulator chip which will serve as an adjustable bec. I also found a 12A esc/bec weighing only 6g including wires. Ordered one to see if they lie.

There are "high-voltage" servos available specified to work with 2S-direct but I don't have any.
Aug 24, 2019, 06:47 PM
Registered User
Markran's Avatar
Phil W and Hard Line,

Thanks for your respective updates.

Mine plane hasn't arrived yet. Any day now!
Aug 28, 2019, 07:59 AM
Registered User
I am thinking about putting my second one together. I got lucky & caught the sale when Hobby King were clearing the last few after discontinuing the model. Got it for US$ 60

I figured they are so light they would not stand up too well. Wrong, they are really quite tough, mine's been flying for almost 3 years. My only problem was seeing it in cloud. I painted just the tail bright red. Not great for aesthetics, but it is easy to find in cloud.
Aug 29, 2019, 04:26 PM
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uncookedlentil's Avatar
I've got an old one also, leaning towards hot flaming pink as it's getting kinda tatty looking! Just need to figure out how to semi permanently install the bell motor to its' post as the grub screws keep chewing their way off, no matter how I tighten them.


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