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Old Sep 21, 2013, 01:22 PM
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Gaui X3 Build Thread

Following not so hot on the heels of my Gaui X4 build I've decided to add an X3 to my stable. The idea behind the X3 is mainly to replace my 250 DFC as my practice heli and to try to eliminate some of the headaches that tiny CNC parts create in crashes. I've really decided that I'm willing to deal with more damage in a crash so long as it's easier to repair and less temperamental. To that end the X3 seemed like a good move with bigger shafts and a good dose of plastic.

First off are a few pictures of the X3 unboxed. Initial impressions are good. It certainly can't compete with it's big brother on size but parts quality seems very good. The canopy fit and finish seems just a bit of a step down from my X4, thinner material and thinner paint I think. As you can see I'm doing a 6S build with 350mm blades. Don't let the Hyperion motor fool you, it's actually a rebadged Scorpion 2221-1630kv motor. For $26 bucks (vs $79) I was OK with blue and silver anodizing over black and gold I've still got servos, ESC, pinions (12T and 13T), AR7200BX and a few odds and ends on the way so I'll update when those are in and ready for install.

Step 1! Bearing blocks! This is my first exposure to the plastic fantastic that is the building blocks of the X3. Initial impressions are an A+! The blocks are fiber reinforced plastic of the high quality sort, tolerances are very very tight. Everything fits perfectly. The RCMainia build shows gluing the bearings in place but honestly I'm not a fan of that. The bearings fit quite snugly and take a hefty squeeze to get in, also the arrangement of the blocks ensures their retention, glue is superfluous here and just gets in the way if you ever want to replace a bearing in a good block.

Step 2: Bearing blocks and frame. As you may notice I don't have any servos in the subframe between the bearing blocks. This is because I haven't got them in the mail yet. For those wondering I've got a set of Savox metal geared servos on the way. I'm only a decent pilot so mid range will do just fine for me. Anyways, even minus servos the bearing blocks practically snap into the side frames the machining is so precise. The CF side plates, per Gaui's usual are nicely cut and have nice smooth edges. It's important to note that the lower bearing block has slightly slotted holes so no need to completely tighten the screws just yet. As with any screws into plastic, they only need to be snug. This plastic takes screws very well but no need to try and muscle it.

Step 3: Landing gear and boom block. As you can see the landing gear is one piece, it's fairly flexible but just for good measure I boiled this set. I'm pretty easy on landing gear but a little extra give never hurts. Now we come to the first questionable design choice I've seen: The landing gear screws into plastic. As Gaui, how hard would it have been to do a bolt into a captured nylock nut to hold the gear on? I just see the possibility of wearing out the holes in the bottom plate after a few crashes where the gear needs replacing. It's a small gripe, so far so good! The tail block goes in nicely, again no need to tighten anything down yet. There is an additional bolt to allow the boom to be pinned.

After the frame assembly I test fit one of the batteries. It's a snug fit between the frames as these batteries are right on Gaui's maximum dimensions. So, pay attention to the battery dimensions, there's no fudge factor in there. I'm going to mount the batteries using tape since I don't think there's enough room for a Velcro strap... that means Gaui needs to get on with putting just battery trays up for sale.

Next up will be the main gear and OWB assembly steps! I need to actually do them first so I should get on that.

Speaking of the OWB, a small point of discussion of the issues some folks have had gluing the OWB shaft. I've heard scuffing the shaft is needed and cleaning is needed to get a good bond. I'll be doing that and adding a key inspired by the RCmainia instructions. That OWB sleeve isn't going anywhere!

To be continued when I get some more time!
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Old Sep 21, 2013, 02:44 PM
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Excellent! Is it done yet?
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Old Sep 22, 2013, 05:59 AM
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Does the plastic boom clamp on the frame have a spot, by default, to pin the boom?
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Old Sep 22, 2013, 11:22 AM
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Nope, not done yet, but I'm working on it!

Quote:
Originally Posted by IntegrityHndywrk View Post
Does the plastic boom clamp on the frame have a spot, by default, to pin the boom?
Yep, it does have an extra hole on one side of the boom clamp for pinning. I circled the pinning bolt in the pic I'm attaching, it's a bit tough to see, black bolt on black CF and all that. I'm not sure if the boom is pre-drilled for pinning , I haven't looked yet.

One bit of advice for anyone planning on getting this kit, if you don't have snap ring pliers, get some. Trying to put on the OWB sleeve snap ring without one would be a total PITA.
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Old Sep 22, 2013, 11:57 AM
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Hi Tom,
Well see you went all the way uptown with Helis. Gaui are very fine birds. I have been flying Micos 100 size and couple Master c/p's. Ready to go for 450's and getting couple ready. Most of my flying has been indoors but out side laterly. Fall is nice here in Tucson, as you well know. It would be nice to ask you in person some question as kinda doing this heli thing on my own. Doing ok and flying alot but need to expand my horizons as they say. Never hurts to learn as much as possible about our little whirly birds.
Anyway best with your X3 buils and good flying with X4. I have flown X5/ X7 on 6.5 G/P sim and tollay awesome, but thats not real life. Even on sim birds are velvet smooth. I have 300X/ 450D and for later 500 D on its way.
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Old Sep 22, 2013, 12:09 PM
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Quote:
Originally Posted by TucsonFlyer View Post
One bit of advice for anyone planning on getting this kit, if you don't have snap ring pliers, get some. Trying to put on the OWB sleeve snap ring without one would be a total PITA.
Oh yeah, this is a crucial tool for Gaui drive systems. I'm surprised your X4 didn't require one to access the OWB. Both the X5 and X7 use them. Except the "strengthened upgrade" auto hub and OWB on the X7 do not. I picked mine up at Anythingheli.com for like $7 or $8. http://www.anythingheli.com/c-clip-pliers-w-4-attachments-5-piece-set/
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Old Sep 22, 2013, 05:41 PM
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Quote:
Originally Posted by IntegrityHndywrk View Post
Oh yeah, this is a crucial tool for Gaui drive systems. I'm surprised your X4 didn't require one to access the OWB. Both the X5 and X7 use them. Except the "strengthened upgrade" auto hub and OWB on the X7 do not. I picked mine up at Anythingheli.com for like $7 or $8. http://www.anythingheli.com/c-clip-pliers-w-4-attachments-5-piece-set/
Surprisingly because the X4 OWB is sandwiched between two bearings on it's own shaft there's no snap ring. I do highly recommend picking up the correct tool for anyone planning on going Gaui.

Hey Dan, good to hear from you! I'll PM you soon and we should try to work out a time to get together and fly here in Tucson.

Onwards with the build!

Step 4: OWB sleeve assembly. This is an important part to get right on this bird... I sure hope I got it right! The sleeve on which the crown gear mounts is glued onto the OWB sleeve. This is my second gripe with Gaui's design here. In my opinion this should have been either machined in 1 part or have some sort of pinch clamp construction. Instead we have glue.

I decided to make things a little more secure so in addition to cleaning and roughing up the surfaces I also took my handy needle files and carved a keyway between the two parts. This took a little while to do right but in the end I had my sewing pin "key" in the sleeve key and with the help of a deep socket tapped the crown gear hat over the key while also gluing it in place with green Loctite. After inserting the key I was unable to turn the crown gear even applying a lot of force by hand so the glue is really now just in case rather than the primary support.

After assembling the main gear and OWB onto the sleeve and securing the snap ring it was on to installing the main shaft. The kit includes spacers for the top of the OWB sleeve to go against the bearing block. If you use one, I recommend using a smear of grease to stick the spacer on before you slide the gear assembly in. Also remember that we left the lower bearing block loose in it's slotted holes for this moment, so tighten up the lower bearing block to take up any slop.

Step 5: The head. Honestly, the head is super easy to assemble. One gotcha, the inner thrust bearing race is pre-installed in the grips so don't panic if you can't find it in the bag The 5mm spindle is extra burly and should take some punishment. Plastic grips felt good and assembled there was no slop at all, just like it ought to be. I do wish that Gaui had gone with normal two bearings rather than one on the grips plus the thrust bearing. Then again at the 450 size it might not be needed.

Step 6: The swash. This is where the kit begins to feel more like a builder's kit. Not to worry, assembly is really simple here too. The plastic swash arm assembly is very well made so the bearing and retaining screws fit perfectly. The X3 swash is nearly the same width as my X4 for comparison. The CNC bits are red, and shiny. I hope that in a crash if one of the plastic arms breaks off that you can get just the plastic part and retaining screws. That would make the plastic worthwhile and save some $$.

Step 7: Swash driver arms. Lots of bearings and washers to keep track of here but nothing to worry about. 4 bearings per arm is nice and they move nice and smoothly. If you're thinking that 'gee those ball links are big' it's because they're the same size as on my X5. Very convenient and it meant that I could use my handy ball link wrenches and save my fingers. All in all the manual is clear on the build here, just pay attention to the direction the arms go because one bearing holder is shallower than the other.

Ok, if you're following along in the manual, I'm skipping a step here. I'm not assembling the head, swash and servo links just yet. I've got servos, ESC, pinions and FBL unit all coming Wednesday so I'm going to hold off till then.

Step 8: Canopy mounts and swash guide. If you look closely at the pics you'll see that I've only just started the screws for the swash guide. That's because I'm going to have to remove it when I install and adjust my linkages so I just started them in there so I don't forget later on. Canopy mounts are normal, no surprises. I might have liked a CNC part here, mainly for the screw down hole you usually get in CNC ones. Also the tiny hex key in the kit is weaksauce, it barely is up to the task of inserting the stubs without stripping.

Test fitting the canopy seems like everything's good so far, but there's no electronics or anything on the nose so we'll revisit later. As I mentioned I didn't feel that the canopy was quite up to the same quality as my X4's lid and I was right. The trimming on the back wings of the X3 canopy is mildly uneven and the molding is a bit off too, but only at the very back. I'm going to come back to this one once I get all the electronics installed and then likely take some sandpaper and a heat gun to the back of the canopy to even it out. I know I'm being OCD about this so it's not a big deal but please have a look at my pics and see what you think.

I'm going to keep plugging along on the tail. Let me know if anyone has questions or comments!
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Old Sep 23, 2013, 08:41 PM
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Onwards with the build!

Step 9: Tail Box. The tail box goes together like any other gaui X series tail box, just in plastic. This is one of those places where precision in manufacturing is important and gaui doesn't disappoint. The gears are a bit on the tight side but apparently they need a bit of running in according to other folks who've done the build.

Step 10: Tail grips and slider. These come pre-assembled, I did dis-assemble and re-check the grips but only checked the slider for Loctite. Everything fits nicely onto the tail shaft and The dog bones all have bushings. The pitch arm is the next part to go on. Now, a bit of warning, this is a somewhat spindly part and there aren't a lot of thick walls on the plastic so it's important to be sure the bearings go in square and that the screws on the arms don't get over tightened. All told I'm really liking the X7 style dual point slider far more than the old style slider, it's very very smooth and should give this thing a nice solid tail.

Step 11: Torque Tube and tail boom. This, I feel, is another questionable design decision, gluing on the TT ends without pinning is a mistake in my book. To do it properly we need to again venture away from the manual. First, I grabbed my faithful needle files and roughed up the mating surfaces on both the ends and gave them a good cleaning. Next I used green Loctite to glue the ends and let it cure for a few hours. So far so good, and honestly I tried breaking them loose and wasn't able to by hand but that's not going to cut it. Out came the drift punch and drill. I pinned the ends with a couple of spare 1.5mm bolts glued in with green Loctite and then trimmed the excess flush with the TT. No loose TT ends for me!

Step 12: Assembling the tail. So all the parts come together here. First the front TT gear and the TT are added to the boom and then inserted through the boom block. The front TT gear is axially supported by a bearing at the front which I really wish had been a feature on my X4! This makes setting the tail mesh very easy. Next the tail box and fin went on the back and I tightened up the boom block. The tail box is only on gently and can be adjusted since I may have to do some tweaking as I install the servos. Also an error in the manual shows a hole for the pinning screw on the tail end, there's no hole but you can apparently screw the self tapping pinning screw right into the boom. I also plan to pin the front of the boom but that will wait for last.

That's it for today, I have a few more pics with mocked in blades and with the canopy on and I have to say she's looking really good. I don't get the remainder of my electronics and pinions until Wednesday so the build will be on hold till then. I've got a couple of adjustments to try for gear meshes and the tail so if they pan out I'll add an update! Until next time...
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Old Sep 24, 2013, 01:33 PM
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Heli sure look purdy !! Really outstanding build. May you have great sucess with this and other Gaui. Feel bad as I passed up a basic Gaui X4 kit. Had a trade and deal was more than fair but passed. I have an Exi pro carbon kit and plan on using good electonic in. Nothing great but bird looks fine and have no desire being best heli flyer Ever. Anyway a very complete and well organized build.
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Old Sep 24, 2013, 08:20 PM
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Old Sep 26, 2013, 11:34 AM
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I'm glad you guys are enjoying the build! I know I am. The FedEx guy brought the rest of my electronics yesterday, so now all I have to do is put all that stuff into the frame and do setup. Apparently I need to make a run to the hardware as well, I ran out of heat shrink, solder and JBweld on the X4 build and promptly forgot I was out
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Old Sep 26, 2013, 08:38 PM
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Quote:
Originally Posted by TucsonFlyer View Post
I'm glad you guys are enjoying the build! I know I am. The FedEx guy brought the rest of my electronics yesterday, so now all I have to do is put all that stuff into the frame and do setup. Apparently I need to make a run to the hardware as well, I ran out of heat shrink, solder and JBweld on the X4 build and promptly forgot I was out
Are those 0257MG servos? Looks like Savox has cheapened the packaging, but probably not the price tag. They used to come in nice plastic box which becomes a useful storage device. I hope they still give you the 3 sticker sheets in there at least.
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Old Sep 27, 2013, 12:37 AM
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They're the 251MG's, when I was looking the 257's and 263's were both out of stock or in 1's and 2's wherever I looked. We'll see how they do, if it's not up to snuff I'll snag something nicer when they come in stock.

I'm also finding out that the Castle 50 lite is not as flat as it looks in pictures, it's actually fairly thick and weirdly shaped. No worries though, I'm just going to have to do a bit of modifying to the ESC plate to make everything fit OK. Both my ESC and batteries are at or near the limit of the size that can fit under the canopy so it's no surprise that it's going to take some finessing to make everything fit.

Also, it sounds like Gaui is listening and will be offering revised parts for the OWB sleeve, TT ends and also offering battery tray 2 packs for sale. Not sure if they'll be free to early batch owners but we'll see.
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Old Sep 30, 2013, 04:59 PM
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Hi all, I just got back from traveling over the weekend so I haven't really gotten to any work on the X3. I'll do some tonight as soon as I get some time.

I did do a little fiddling with the ESC and it turns out the 50 lite will actually fit the ESC plate without modification, the trick is to get it low on the plate towards the nose and to route the motor wires on the outside of the frame. I'll take some pics this evening but it's looking like I won't have to mod anything. The canopy fit is still pretty snug but not canopy crackingly so.

I'm not sure if I mentioned but I did get all the soldering for the build done last week. EC5's are my standard connector now for 6S and I feel like I did a much better job with them than on the X4. I also picked up a new soldering iron with some oomph to it which made a huge difference in ease of soldering.

Things are moving along nicely tho, once I get the ESC position finalized I'll be able to test servos, the FBL unit, route wires and set up my swash links. After that the plan is to set up the FBL unit and mod the front of the frame for the battery wires and then we ought to be ready to go flying!
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Old Sep 30, 2013, 07:14 PM
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Originally Posted by TucsonFlyer View Post
Hi all, I just got back from traveling over the weekend so I haven't really gotten to any work on the X3. I'll do some tonight as soon as I get some time.

I did do a little fiddling with the ESC and it turns out the 50 lite will actually fit the ESC plate without modification, the trick is to get it low on the plate towards the nose and to route the motor wires on the outside of the frame. I'll take some pics this evening but it's looking like I won't have to mod anything. The canopy fit is still pretty snug but not canopy crackingly so.

I'm not sure if I mentioned but I did get all the soldering for the build done last week. EC5's are my standard connector now for 6S and I feel like I did a much better job with them than on the X4. I also picked up a new soldering iron with some oomph to it which made a huge difference in ease of soldering.

Things are moving along nicely tho, once I get the ESC position finalized I'll be able to test servos, the FBL unit, route wires and set up my swash links. After that the plan is to set up the FBL unit and mod the front of the frame for the battery wires and then we ought to be ready to go flying!
Sounds a lot like how the ESC mounting is on my x7. It makes for what i consider to be a high liability mounting position for the ESC. Also if i didn't mount the ESC low enough it pressed against the inside of the canopy and made pressure dents that were like little bumps you could see from the outside of the canopy.... But i don't have to worry about that anymore since my canopy fell off while flying the other day! Yippie!
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