I knew going into this that the Nimbus was no SAB in terms of quality, I didn't expect it to be bad or overly problematic. The goal was to build a relatively simple budget copter of the 550 size. The main difference is that SAB thinks of everything. There is nothing in those designs or builds that is out of place. The opposite is the case with the Nimbus however. There are a lot of small design quirks and build issues that on their own are not serious problems, but when you put them all together it creates a problemcopter.

The biggest one being the issue of standard servos versus mini servos on the cyclic. If you are thinking on putting in mini servos because you will save money, don't try it. At least on Helidirect and I think also on XLPower's website, they only sell a model that has a servo mount for standard servos. If you want the mini servos, you have to go buy new servo mounts, a main shaft block and bearings (if you accidentally stuffed the standard one like I did). This adds another $50-$60 not including shipping. Worst of all the servo washer that comes with it is only for the standard size and they DON'T MAKE SMALLER MINI SIZED ONES FOR MINI SERVOS. So you have to either modify the existing ones or source other ones from another craft. The manual does not mention any of this BTW, you are just simply supposed to know better. Secondly, the spindle shaft dampers are two piece and are slightly different sizes. If you manage to put the wrong one in the blade grip you will never get it out without destroying it or the blade grip. If the damper is in wrong it may cause the spindle shaft to not rotate as freely as it should. There is nothing in the manual or even the videos about this, since the manual is for an older version of this kit. Thirdly, the canopy mounts tend to vibrate apart and disintegrate in flight which is a problem because they are relatively expensive compared to most other parts. Fourthly, the battery tray width is strict and you should be careful what battery you put in there. If it is too wide, the straps will catch preventing the tray from going in. If you do a lengthwise strap, be careful that it does not slip off the battery or it will launch out because there is no bottom. Fifthly, the tail boom sucks. There is a screw that punches into the metal to hold its location, take your time setting it up because if you screw up you will have to buy a new tail boom since adjusting it will be next to impossible. Sixthly, the published lengths of the ball link rods given in the manual are for the standard servo layout. If you are doing minis, you have to guestimate a length so that your leveled servo arm will give zero collective. They do not mention this nor do they publish lengths you just have to figure it out yourself. Seventhly, there were some bad threads in some of the parts. I nearly got a screw stuck because they didn't clear the chips out of one of the holes on the center plate. It could be a fluke and I have seen this sort of thing in other kits but it's still not a good look. Be ready with some metric taps if you buy this kit.

The flight characteristics are as good as people say it is. It seems to do well at low rpms and is very agile and scary fast at high rpms. It has lots of power and autorotates well. With a battery loaded, the weight is roughly 2.2kg. They do not publish any recommended headspeeds or max headspeed. I guess you will blow out your tail out on the low end and blow the rotor head apart on the high end. I had a bit of a vibration issue at 1500-1600 rpm where you can see the skids move and 2500 it rattled one of the canopy mount apart; between 1800 and 2200 it seems fine. I don't know if it was the blades being out of balance (Vulcan blades) or the rotor head not being assembled correctly. I also don't know how much vibration I should expect from a 550 size heli. I have a 420 size SAB that flies infinitely smoother than this but then again it's smaller.

This heli may have a lower parts count and a better acclaim than some but it is definitely not a beginner machine. This is for a pro who knows what he is doing, has extra parts and want's a cheaper practice flyer or a beater copter. Do not buy this expecting to save money, do not buy this expecting it to be easy to build. I probably should have bought an OMP M5 or even an Align Trex 550X. It appears my expectations were just not aligned with reality. All that being said, there are no major design flaws with the powertrain, head and tail. It flies as good as you would expect a modern helicopter to fly.

After checking it out on here and a friend getting this kit I decided to get one of each kit the electric and the nitro. I really like the parts compatibility between them and the fit and build went fast and well. I can't wait to fly them both. Going to be my everyday machines to learn more 3D on. Parts are very reasonable too. Canopies are a work of art.

Nice time putting this one together. The instructions has a few mistakes that didn’t coordinate with newer parts. Other than that it was all good. Be careful to check loctite and retaining compound on preassembled parts.

Cant wait to open and put together

There was no manual included with the kit. I had to go to the XL website to download a copy, then print it. The kit looks great.

This is my 3rd nimbus having 2 nitros I wanted the electric version also. Was not disappointed, excellent kit and they fly very well.

Easy to build and I appreciate design is carefully thought through. It flys silky smooth and great for beginners or under a skill pilot it can handle any thing you throw at it. A 550 size heli that flies like a 700. You won’t be disappointed.

The head did not fit on the main shaft. After consulting with my friends who have the same Heli, I contacted Heli Direct. Patrick sent me a new head in a couple days. Problem solved. I have built over 90 R/C Helicopters and never had a part that didn't fit.
The Heli build was easy, and it flew well.

Amazing product, shipping was packaging was good. Got up in the air , flys amazingly

The kit is amazing quality for the money and it needs to be judged for what it is. The kit was designed to be a practice machine for hardcore 3D pilots that could be crashed and fixed quickly and for less money than other brands. That being said, the parts quality, fitment, and hardware are amazing. The canopy is very nice too, the quick connect/magnet system should be the standard with every manufacturer these days. Top quality materials are used. The company is able to deliver these kits at such a good price point because they are saving money elsewhere. You don’t get fancy packaging and a great manual like SAB kits. There aren’t as many complicated design features like a belt tensioning system, turnbuckles for each cyclic servo, or any cool little free tools. What you get is a well designed, easy to maintain, simple to build and fix machine that is designed to shred. It’s a baby sister to the Specter V2 and flies like it, giving you a familiar feel and visual experience. I would recommend XGuard magic dampers (as with any rigid head POM dampened system) to rid the machine of any low RPM vibrations during spool up/spool down. I haven’t don’t any autorations on the machine yet, but there are a few videos on YouTube. To me, it looks like the best autorotating 550 size machine yet.
Pros- machine quality, hardware quality, simplified design, PARTS COST, ease of build, flight performance, ability to run up to 580mm main blades, rigid frame, large battery compartment able to fit up to 8s packs, inexpensive 650 stretch kit available, hang time on autorations (stellar for the 550 class), nice canopy with magnets and quick connect. Let’s not forget the 1:1 ratio for the head geometry! You get a nice, precise, predictable/natural feel that’s easy to adapt to, especially with Azure Power blades.

Cons- digital manual (does ANYBODY like those?!) instead of nice quality paper manual. The manual is pretty vague; if this was your first kit build you would be left guessing on a few details. The canopy for both the nitro and the electric are the same, so there is a hole for the starter wand on the electric model. This doesn’t actually bother me, I think it’s a clever cost-reducing tactic, but some may not like it. There is only one option for head dampening included in the kit, and the POM dampeners needed a tiny bit of de-burring to remove some plastic left over from manufacturing. The main gear and tail belt may be mechanically sound, but I prefer the beefy look of thicker main gears and wider tail belts found on other models. There is only one battery tray included and you don’t get real battery straps that have a buckle to leverage the strap through, instead you get a wider version of their hook a loop tape roll to secure the packs to the battery tray. The Velcro that’s included for mounting batteries to the trays is not awesome. Just buy real, heavy duty Velcro brand tape. No turnbuckles for cyclic servos, although the swash-to-blade grip turnbuckles seem like they would work fine if you were to buy more and use those. Ironically, they are not that inexpensive at $10 for the set of two, meaning you would need two sets to get the 3 turnbuckles you need for the servos.
My biggest gripe is that the tail boom is not keyed for alignment. This would be such an easy feature to incorporate- just cut a slot
In the boom that aligns with the tail fin mounting holes and add a small block of material to inside of one of the boom mounts. It would make belt tensioning so much easier- I hate trying to square up a boom while pulling on it to get the correct belt tension, and simultaneously needing a magical third hand to tighten the hardware.
If XLPower would address these small issues, the kit would be even more amazing. Overall I would highly recommend the kit. If you’re aspiring to be a competition pilot (or just crash a lot learning or pushing the limits) or just want a really solid modern machine with great value in parts cost and parts availability, I would say this is kit to get.