Photos of my new SC10 body in progress, along with the final result.
Test fitting the new body, and marking for the body clip posts: SC10 Body B - measuring for mounting holes.
Masked and ready for paint: Body masked for the first stage of painting (main color)
Primary color applied. This silver does not adhere well, so I had to apply 4 main coats: First few coats of main color go on.
After the 4 main coats of silver, 2 rounds of spot touch-ups were required: After 4 main coats and 2 rounds of touchup. Main color is complete.
Next the detail colors were laid down. First the Competition Orange applies to fenders and sides. Next was the black layer for door stripes, and finally, a small layer of white for the detail stripe down the door stripe center. My experiment in using Sharpie pens to add some line detail to the body, mostly failed. I was able to apply the lines with acceptable results, but contact with the paint caused the lines to start bleed, making them puff-up, which is what you see in the photos. Big, soft Stay-Pufft like lines. It was a useful experiment. Nearly completed result after 3 more colors applied.
After completing all the layers and a little touch-up in corners, all the masks are removed to reveal the bare painted shell. Paint completed and all masks removed.
Finally, the end result, at least for now. A small amount of decals applies to give it some visual interest. The challenge here is to resist the urge to over-do the decals. I have piles of them, and the temptation to turn the thing into 3lb. rolling bill-board is sometimes bothersome. Final Result.
A few of you may have noticed that this is not a Team Associated body, in fact it’s manufactured by their main rival. I selected this body for several reasons:
On the heels of the 4 hour Enduro race just 2 days before, turnout was pretty light for a Monday night. In fact, there really wasn’t enough depth in each field to run the normal Novice, Stock and Open class for each vehicle type. So, instead of being able to race in Novice class, I was pitted with the Stock and Open truck racers that have been doing this for a long time. It was going to be a learning experience!
This week I was prepared with plenty of battery power, a dialed in rear differential, upgraded toolbox and new carrier box too. My pit space was a lot more organized than last time. SC10 being prepped for the first race.
We ran 2 heats and a main event for “Truck” and “Buggy”. I held my own in the first two heats, finishing near mid-field, and certainly not last. I’d learned quite a bit in my first race the week prior, and it was paying off.
At the end of the first two heats, I have qualified 6th in a field of 10. Not amazing, but better than I had expected, considering I was not racing all Novice racers, and not all stock trucks (some of them were a lot faster on the long straight than my 13.5 powered sled).
We ran a 10 minute main event. It was chaos. Lots of vehicle contact, more a lot of rollovers. We kept the track marshals very busy. About 15 laps or so into the race I was starting to find my pace, and able to get all the way around the track without a running across the edges, without crashing out (without being crashed out by others) and hitting a pretty good rhythm on the double-double and double-triple jump sections.
To my pleasant surprise, I managed to cut a couple of very fast laps, that got the attention of the race caller and timer. What I noticed on the runs I did really well on, despite a sea of surging Lexan, if I put all the other vehicles out of my mind, not looking at relative speed to the other races, or where they were lining up their trucks, basically running like I was the only person on the track, I was much smoother and much faster. Sure, a couple of times I got pitted around by another truck, and I did t-bone another racer on who was much slower on the long straight, but, nobody got broken, and neither of us had to be recovered. It’s not going to be a strategy that will work 100% of the time, but I found that greater concentration on the line that is best for MY truck, my tires, my drivetrain and skill, I do much better.
In the end, the 6 1/2 hours I spent at the track testing, tuning and finally racing was so much fun, I was smiling for hours and hours afterward. And one of the test parts of all this, the 6 1/2 hours of entertainment, and friendship, cost me a grand total of $9.37. That’s a pretty good value, don’t you think?
SC10 ready for action. But not so pretty any longer.
This past Monday, I took the plunge and ran my first full race with the re-bodied SC10 truck. SC10 truck in the pits during Monday Races at Bremerton RC Raceway.
It was a real blast, but I have A LOT to learn about truck setup before I’m going to be competitive. The most challenging issue I’m facing right now, is the speed of the steering servo. It’s too fast! It makes the truck feel really loose. When hitting full throttle down the main straight, it’s very difficult to put in a little steering correction. Instead, I’m finding myself loosing control, needing to slow down, and often getting passed while trying to regain control of the truck.
The RC controller I have is made by Futaba. A well known, and respected name in Radio Control for decades. Checking through the manual, I was disheartened to find the radio I’m using does not have any ‘Expo’ (a configurable low-action or dead-zone) settings. It does, however have a Dual-Rate capability on the steering channel (#1), which might allow me to tone down the very fast steering servo. My concern, having not tested it, is that it might make the steering too slow, making the better servo a moot improvement. :/ Things you learn, right?
Even more daunting that the steering issue for me last Monday, was the fact that 45 minutes before the first heat race, I completely destroyed the stock rear differential I’d put after breaking the output shaft on the race differential that came with the truck. Ugh! With not much time, I had to rip apart the entire back end of the truck, remove the transmission, split it’s case and try to slam in a brand new Team Associated ball differential. With the cost of a rebuild kit of the stock costing $30, and a complete new competition ball differential being $40, the decisions was pretty easy. Go for the adjustable diff and learn to set IT up as well. Having been a racer for a long time (full-sized vehicles, that is), I’m well versed in the climbing of the learning curve. You just have to do it. Good racers have a lot of wheel time.
Upside for me, was that Brian (owner of BRCR) was kind enough to build the differential for me, while getting everything else ready for the race, so I could concentrate get the truck apart and back together in time for the race. Final 5 minute call to line up for the race came as I was putting in the last two screws. I selected one of my qualifier battery packs, ran from the pits down to the track and got in line, JUST in time for first heat.
I finished last, several laps down from the leaders, but it was great experience, a lot of fun, and I plan to race again this coming Monday, assume I’ve not broken the truck in the mean time. 🙂
The old Mod-class SC10's body shell.With a few days off, I finally got around to working on a new body for my SC-10 R/C truck. I bought the truck used back in November, and the body on it was trashed. Tires had worn through the paint in the tops of the fenders, every corner was ripped and flapping around, and it was about as visually exciting as a Keanue Reeves movie.
There were a number of options available for the truck from both the OEM (Team Associated) and aftermarket supplies. Prices ranged from $30-$50. There are likely differences I’ll never be aware of, but for me, I decided the $30 OEM body (a Ford) was just fine for me.
Now, the tricky part of working on these things, is the bodies are made of Lexan. Lexan, is a flexible, tough but a rather ‘oily’ feeling plastic, so you need a good paint. One that will adhere to the material, and is formulated with a lot of flex agent in it. These bodies take a beating!
$12 for two cans of spray paint and a couple of hours in the garage, and I was underway. The kit comes with masks for the windows, which were easy apply. This makes the production of a decent looking shell (body) a lot easier. It’s also supplied with a few of the standard Team Associated body decals. There are no sponsor decals in the kit I purchased.
One thing some readers might not be aware of, is that they shells (bodies) are painted on the insider, not the outside. This has a variety of benefits:
Durability – these things crash, A LOT and paint on the outside of the bodywork would not last long. The decals are very thick vinyl, and they still show the wear of normal abuse
Aesthetics – which is akin to the durability already mentioned, however, when one paints these shells, one can be, well, I’ll just say that one can be less than meticulous in your painting, and yet the appearance is always bright, shiny and smooth (at least until you send the thing sliding down the track on it’s roof, which you will do).
Others – there may be others, but at this late hour, I’m unable to consider them
Now, not only do you paint these on the inside, which requires some planning. You can’t simply paint over a mistake, it’s there, on ‘top’ of the paint, for all to see. You can’t just ‘re-paint’ over a mistake. So, plan wisely, paint the darkest colors first, then go to the lightest. Often it’s best to finish up with a white ‘backing’ color.
After the pain is applied, next you’ll need to get out another special tool, Lexan compatible scissors, to cut the vacuum formed shell to it’s final shape. Cutting out the wheel openings, wings (if it’s equipped with such), number boards, etc. It take a little time to get one of these things from this: Standard unpainted SC10 body.
To this: SC10 body painted and trimmed.
And finally this: Final result. Custom painted SC10 Championship body, ready for action.
From start to finish, it took about 36 hours (wall clock) to complete. Effort required, about 3 hours for masking, painting and trimming. And, a lot of waiting while it cured.
I’m pretty happy with the final result, and the old used SC10 looks right at home with it’s brand new stable mates, an Associated T4.1 Truck and an Associated SC10 Short Course (Makita RockStar):
Unfortunately, in the first lap running full-power with the Mod SC10, I blew up the roller-ball limited slip differential. But, that’s an article for another day: One broke truck.
Part of my latest toy delivery was a slightly larger heli than I’ve worked on before. Not wanting to get too far into this before I learned something about the 500’s, I purchases a basic intro kit.
The current plan is to build this kit, screws up, put together a full parts list and get a good estimate of what a real flying 500 will cost to build, with common spares, electronics, batteries etc.
So, onto the kit.
First, this kit arrived in a box smaller than my EXI-450 did. The way the packed the stuff in there was really something else. Here is what the array of parts look like once unpacked: Hobby King HK-T500 Helicopter Kit
So, just exactly how large is the main frame? Pretty big. Closer look at the 500 class alloy frame
Comparison to a fully assembled 450 behind it. Alloy frame and once piece landing skids. 450 Heli sits in background.
Landing gear is a one piece plastic affair. Checking the parts list on the higher-end HK-500GT shows that it uses a multi-piece gear assembly, more in line with 450 kit I have. A detraction, but one that can be solved with the purchase of a 500GT landing gear set (about $5.00). Once piece plastic skids in T500 kit.
Main rotor bearing block is plastic. I had a small issue on the plastic bearing block in my 450, and ended up replacing them with alloy. Checking parts I see that HobbyKing does sell an alloy block for the GT version, however it very clearly states that it DOES NOT fit the T500 model! That could be a major issue ongoing. When they say that it does not fit, I don’t know if that refers to locating pins only, or if the overall dimensions are different enough to prevent use. T500's plastic main bearing block.
The kit does arrive with a set of fiberglass main rotor blades (black / yellow). As you can see, these are not just a little larger than those of a 450 (middle) and more than twice the size of a 250 (bottom, shown for effect). These blades are not only big, but they are heavy! Fiberglass 450 blades I’m using come in at 18.5g each. These bruisers weighed in at 68.6g! Rotor blades, 500, 450 and 250 class.
Main gear set seems serviceable. Operation seems fairly smooth. The trail drive gear is a little wobbly, but that’s been the case on every gearset I’ve seen so far, including a factory Align unit. I’ll take it apart and re-oil the one-way bearing. I did notice that it has not ‘fan blade’ properties to move air like some of the other 450 gearsets I’ve purchased. Main gear set.
Tail boom, servo link, boom support rods and flybar are all in the next package. The tail boom support struts appear to be plastic with plastic ends. Tail boom is typical aluminum alloy. Flybar appears to be stainless steel and quite rugged. Tail boom parts package.
Servo link ends are plastic, but it does not look quite like the quality ball end links typically found in kits. Maybe it’s just the size of them. Closer inspection of boom parts.
Boom holder and tail gear set is a festival of plastic, right down to the cross tube/spacers that screws anchor into. Even on the cheapest of kits I’ve seen so far, that was metal (talking about the 4 bars near photo center). Is it ‘bad’, I don’t know, but I’d prefer to have seen some more metal in there, that’s for sure! Tail drive gear box.
Assembly looks pretty straight forward. Which is good, since they clone kits do not come with any sort of instructions. All the parts fit snug, and turn freely. The screws in the tail kit are allen-drive, but they are on the soft side. While test fitting the parts, without even torquing them down, one of the heads stripped out, requiring the application of a small vice-grip pliers to remove it. If it had been snugged down, it would have been a much more difficult task. I’m considering a trip to Tacoma Screw for a set of torx-drive replacements Tail drive gear box with gears and bearings test fitted.
The tail and tail boom fastening components are all in the next bag: Tail drive and boom fastening parts.
Tail gearbox, blade holders and pitch actuator arms are plastic. Bearbox is nearly completely enclosed, so I’m not able to see the tail drive pully gear, but it also appears to by a white nylon/plastic. Tail rotor drive and gearbox detail.
Knight head, tail rotor fin and tail servo holder are made of metal alloy. Tail boom yoke and servo boom holders are black plastic material. A lot of stamped alloy parts in this bag.
Probably the most important part of all, the main rotor head. One word comes to mind; PLASTIC!. Lots of it. First the overall shot: Main rotor head assembly.
Main head, it’s a beast. 132mm across (grip to grip) it’s 33% larger than the same part of a 450. And, aside from the feathering shaft and bearings, it’s all plastic. Having broken a plastic blade grip on a 450 recently, a similar crash might crack the entire fly head on this bad boy. Main rotor blade grip and feathering assembly.
Swash plate on this is part composite, part alloy. Linkages seems appropriately constructed on the head and swash. Pictures can be worth a few hundred words, so here is the picture. Main rotor head, swash plate detail.
Another of the links, washout arms and tracking links. Main rotor head details.
Flybar paddles. Plastic. I’m not sure what the deal is with the vents, and the pack of decals. Based on what I’ve seen on other photos, the decals are applied to the blades to cover the ‘vents’. Perhaps those are simply there to lighten the paddles, and the decals cover the holes to make the paddles work. I’ll have to look into this further. Flybar paddles and decals.
Anti-rotation bracket and canopy stays. Also….. (wait for it….. waaiiiiiiiiit). Plastic.
[PIC 20]
One last package of stuff. Hardware, blade holders and two different sized pairs of hook-and-loop straps. Also in the bag are two sizes of velcro adhesive pads, two bags of extra fastening hardware, servo horn accessories, balls and a pair of monster motor pinions. Of note in this bag, is also a bottle of purple 222 thread lock. I already have a monster bottle that I have used on all my kits. I just find it interesting because just about everyone is using the heavier duty blue which I’m certain is the WRONG type. Having more than a passing background in auto and motorcycle repair, you need to use the right locker for the right size fasteners. Blue (242) is really for much larger hardware. Purple (222) is the right stuff for small fasteners. Now I have a little validation (beyond what the TRex assembly manuals show) with the inclusion of 222 Purple in the kit. Good to know! Last general hardware parts bag, revealed.
Last is the canopy. And it’s BIG. The canopy stay holes also need to be enlarged to work with the supplied (white this time) rubber bushings. That is one of the first things I’m going to do, since I want to design at moderately nice looking canopy design for this monster.
It would be harder to send a cheaper canopy! It’s simple resin, like EXI-450 kit supplies, but in this case it does not have even have the ‘cockpit’ canopy detail on it. It’s just… all white. I put a spare 450 canopy in front, and my coffee mug in the photo to give some scale. T500 and 450 canopy scale comparison.
So, there you have it. Unpacking the HobbyKing HK-T500 electric R/C helicopter kit.
My latest toy box (or box of toys) arrived during the conference this week. I’ve had a lot of time to work on building this machine, but I did manage to get some HXT-900 cyclic servers and a general test/fix mockup completed. ! I still have to order several parts before it will fly.
250 / 300 class ourunner motor (400 won’t fit.. bummer)
Bent tail boom after crashRepairs are underway, following my flight yesterday, where I ran out of altitude. Breaking things is seldom enjoyable.
But it’s the risk you have to take if you’re going to fly these things, especially when there are gusty winds. There are plenty of YouTube videos showing real helicopters having trouble with wind, sometimes with tragic results. I
In the grand scheme of things, a little bit of bent aluminum is hardly much to worry about. Being grounded with a busted helicopter is still not the ideal situation.
I noted yesterday that the Blade 400 tail tube turns out to be remarkably similar in dimension to the one used on the 450. I really would have thought that the ‘smaller’ 400 class model would have a shorter tail boom, but it turns out to be about 15mm longer. Comparison of Blade 400 tube (top) and EXI-450 tube (bent)
Easy enough to rectify. A little cutting, sanding and filing is all it took.
The new tail boom, and new Sport alloy tail case are now installed on the helicopter. One of the advantages of the new Sport tail case, is an alignment pin (the original did not have, it uses the hole seen in the blade 400 tube) that keeps the tail case from rotating. An issue I had a couple of times with the original part. New tail boom installed.
A closer look at the alloy tail case, new tail rotor blades also installed: New alloy sport tail case.
During lunch I’ll be able to finish mounting the tail servo, knight head and support bars.
UPDATE:
I just checked on the status of the replacement parts and some other fun stuff I ordered from China, using the ‘slow-boat 7-45 day shipping’ option. I regretted not spending the extra $20 for faster EMS 3-5 day shipping, until I checked the shipping status this morning!
For a slow boat from China (OK, it’s air post but the website said expect 7-45 days transit), it’s already here in the states. I just needs to clear customs. Not sure who long that will take but, you know I’m going to post here when it does! Slow boat from China my ***! 🙂
Tonight, I’m picking up where I left off yesterday[LINK], while I listen to some awesome local High School Radio (KNHC).
Sunday nights from 6PM -> Midnight is Industrial and Alt music show called ‘On the Edge‘. Reminds me of a similar show that used too broadcast on KFJC out of Foothill College in the Bay Area. Most of my good German Industrial music collection was the direct result of hearing it on that show.
Back to the Overhaul
I’ve been doing some research today on blade balancing. Picked up a couple of new tricks, talked to a few of the local experts and I’ve come up with what I feel is a comprehensive, but not exhaustive (aka anal retentive) balancing strategy. Here is my take on this VERY IMPORTANT task:
First off, getting some good tracking tape has proven to be a major challenge for me. Today I solved that problem, thanks to advice of a local flyer. He’s been using Monokote (I’m quite familiar with the heat-shrink version of it, having first used it almost 30 years ago). I picked up a high-vis red and contrasting orange in the adhesive backed variety. Preparing to balance blades.
I don’t plan to balance the other 4 sets of blades I have tonight, just the set I’ll be using for the final run-ups once I have the bird back together.
The first step in balancing, is to find the COG (Center of Gravity) on each blade. I did this by rolling each blade on top of a spare flybar rod (it’s about 3mm in diameter) until I found the balance point. Once I did that I marked it with a permanent marker. This is done for both blades. The purpose of this is to determine how much balance weight you need to add to get the blades balanced our along each blade itself. Ideally you take the lighter of the two blades (if you have a scale that’s easier to determine, otherwise your normal blade balancing fixture will tell this tail), apply weight in the right locations to get both blades to have the exact same COG. I’ve done this already, the top blade has a little clear plastic tape used to weight it on the right side. Here the COG’s are in the same location on both blades. Locating the center of gravity on each blade
Next I’m going to take equal pieces of the adhesive backed monokote, and apply a different color to the tips of each blade. Make sure the size of the monokote you apply to each is identical. They must also be applied in identical locations. Here is what it should look like *before* performing the final balance. Adding contrasting blade tip colors. Critical to setting blade tracking
Next, set up the balancing rig and dynamically balance out the blades. Any weight, if required should be added to the light blade at it’s COG (which is why it’s marked across the pitch). Even though these blades are very close in overall balance, one blade does need a little bit more, to fully balance it out. Blades on jig for balancing.
Once balanced, I moved back to the process of rebuilding the head. I had a lot of experience with the V2 head, but not the older Version 1 head that I had to buy parts for (no V2 parts available locally or online from the plethora of vendors, odd really). Interwebs to the rescue! I found an original ALIGN 450SE (v1) build manual with the exploded view of the V1 head! ALIGN 450SE (version 1) exploded head view. (click image to enlarge)
Somewhere in the box of parts is the main head, and all it’s associated bearings. Box of 450 class helicopter parts
The most important bag today, the main rotor head and blade grip components
There are a lot of parts that go into the grips alone! That’s 6 bearings, 2 spacers, 2 washers and 2 bolts, not to mention the 4 o-rings (dampners) and the feathering shaft itself (already installed in head).
Having the instructions made assembly straight forward and quick. It took longer to write this pragraph and take the photo, than it did to put together, install, locktite and tighten the grips. They seem very firm and turn very smoothly. A HUGE improvement over what I was attempting with the hybrid V2 guts and V1 components. I knew better, but I wanted to see how close I could get. Not close enough. At any rate, here it is, assembled. Blade grips installed. This is a partially assembled main rotor head top-end.
The next step is to attach the rest of the upper head’s running gear. The flybar seesaw holder was a little problematic. Gunk in the bushings had it binding up. Finally resorting to application of some firearms cleaning techniques (and fluids) cleared up the gunk. Re-application of all locktites was of course required after being exposed to solvents. Added a little CLP to the bushings to keep the running smooth. Pitch arms were next and those when back together without drama. This is what I have now; This is a fully assembled main rotor head top-end.
It was finally time to bolt the head to main shaft, insert flybar, line up the washout shafts and block, hook up swash coupling links and get ready to finish the top-end rebuild of this bird. Upper, middle and lower sections of main rotor head assembled and installed. Swash Plate is that beast of link buttons on the bottom.
While upgrading parts, I decided to swap out the temporary Blade 300 flybar paddles (smaller, top) for the larger genuine ALIGN 450 parts. They are basically twice as thick, have actual airfoils and weight 8.8g, compared to the Blade 400 units which are 2.7g. The orginal EXI flybar blades come in at 4.7g. I tossed them out. One was not factory drilled for the flybar, so I just sorta hogged it out during original construction. Turns out that alignment of that bore is really important to the overall flight characteristics of the bird! They are gone, just in case I forget why they are no longer in use, and put them on something. I’m better off with the flimsy B400 paddles than one that is not drilled properly. Many lessons in these little things. Temporary parts (top) vs. the right parts (bottom). Flybar paddles are critical to all Bell-Hiller head aircraft.
Installed, centered, measured, re-measured, checked for square, re-measured down to .001″ inch. with dial calipers. I’m sure how to get it any more accurately constructed than this! With the blades installed, it’s time to perform the first run-up and blade tracking test. Really, about 9 hours of work comes down to the this moment of truth. Fixed, same or (gulp) worse? Assembled and ready for ground tests. Stand by for....
This video contains the first run-up, before blade tracking was adjusted. Next was post-tracking adjustment. Overall vibration has been reduced significantly! With the replaced bearings and slightly slower head speed the entire things sounds healthier too. Another view in the video displays the blade tracking, and finally a fully assembled bird is run up to 3/4 throttle. A test of the throttle cut and auto-rotation flare action is also examined for function.
Everything looks great and ready for another test flight! Local time on the Pacific Coast here is 23:07. A little too late for test flights. The plan is to give it some air time after work tomorrow.
One other thing I noticed, was that flybar action is much smoother since I completely tore down the head and rebuilt it.
The upside of all this, is that I’m 100% confident I can repair any damage done during a crash, including a full frame up-reconstruction. At some point this fall I’ll probably swap out the metal frame for a V2 carbon fiber setup (about $30). That will drop quite a bit of weight off, and going to a CF tail boom will also shed some weight. The less the entire thing weighs, the less power it will use to remain aloft, which equates to lower operating temperatures for bearings, and longer flight times with the same batteries.
Since I was not 100% certain of the proper method of blade balancing, I’ve started up this page. You see, until 9:00AM this morning I was certain how to properly balance blades. However, after reading the ALIGN Trex450SE instructions, which contain this diagram, I’m not at all certain. Blade Balancing instructions from the ALIGN Trex Instructions.
Up until now, I had placed the blades trailing edges flat on a table, then tightened the balancing tool, and placed it on the jig. The objective was to have the trailing edges of the blades perfectly level. Here is what it looks like: My orginal blade balancing method.
I hope you can see the difference in how I placed the blades together, compared to to what the Align manual suggests. Here is a closeup to help illustrate how I used to do this: Closeup of my balancing method.
Compare this to using the ALIGN documented method: Using the ALIGN balancing method.
As you can see here, not only does it appear quite different, so is the result! Using this method, my blades are out of balance. Or, are they? ALIGN balancing method
Now, I’ve gone out and searched and consulted with the great oracles on this subject (the R/C discussion groups) and found the following:
On one of the most helpful sites I’ve found on the web, Mikey demonstrates the blade balancing using the same method, that seemed intuitive to me. Here is a screen shot from the video: One balance method seen online.
Checking another forum, I found the following this post that discusses first locating the COG (Center of Gravity) on the blades and marking them. Or balancing the COG on the blades so they are the same blade-to-blade, THEN getting them in dynamic balance:
http://www.rcgroups.com/forums/showthread.php?t=878885&highlight=blade+balancing
Hm. there seems to be MUCH more to getting a really great balance on your blades than meets the eye! With the vibration issues I’ve been happening, I’m going to do everything I can to provide as stable a main blade balance as possible.
What is most clear at the point, is that I have A LOT more reading to do. PART 2 will follow once I decide on exactly how I will be balancing my blades. The question of the afix orientation of the blades perists, even after I find the COG of the blades.
This link here looks to be the most concise explaination of a balancing method. [LINK]
I’ve had a few good flights, and few bad flights with the N450V2A. After locating a nasty wobble and some incorrectly manufactured parts, I’ve torn the bird down to just about the bare bones and have started a re-construction.
Starting here with this picture, I have already performed the following.
Replaced the Main bearings in the main bearing blocks. One of the old bearings had a bit of a ‘notchiness’ to it so I tracked down some replacement parts, including two pairs of original Align factory main bearings (5x11x5mm). $6.49. Old EXI main bearings (red) and new Align main bearings (nude)
They are installed at the top of the frame, and in middle, just above the main gearset (in blue). The main gearset has already been replaced with at genuine factory Align part AGNH1218$22.99 Mainshaft and main gearset.
The original Pentium 30A ESC (Electronic Speed Control) was showing signs of overloading and causing in-flight resets! In defense of HobbyWing, it looks like I was running too steep a pinion on the main motor (I’ll get to that later). Regardless, I wanted to make SURE I did not have to learn auto-rotation landing in my first few weeks of flying. So I purchased a new genuine Align 35A ESC with Governor, PN 35ABLESC GOVMD5VBEC RCE-BL$53.99. It’s installed high on the frame now, where the battery would normally be located. I did this to help ensure good air flow along it’s heat sink. New ALIGN 35ABLESC GOVMd5vBEC RCE-BL Speed Controller
As mentioned, it turns out the that original 13T pinon which came with the EXceedRC Alpha 400 63N18 motor is not an appropriate selection. It was suggest that I run either an 11T or 12T pinion by several people online. The local hobby shop had a pretty knowledgeable flyer behind the counter, and suggest a 12T would make a big difference. It’s also the suggested pinion for the factory Align Trec450 V2 (of which mine is a clone). Having already ordered an 11T pinion, I purchased the 12T. Original 13T is on the right, new 12T Align part on the left: Main drive pinions. New 12T ALIGN part (left) and original ExceedRC 13T part I'm replacing, on the right.
The motor itself might be OK. I’m going to re-use it for now. Another is on the way from Hobbypartz.com price about $20.00. The pinion is only firmly mounted on the shaft, since it will have to be precisely adjusted for main gear engagement once I re-install the motor in the frame. Motor re-mounted and gear mesh very carefully set.
Next I went about trying to get the main bearings and main shaft running as true and consistent as possible. The bottom bearing has some manufactured in lateral play, nothing I can do about that. But I did manage to snug up the shaft to bearing interface with some very light knurling of the main shaft where it contacts the lower bearing. Additional play looks like it will come out with a slight ‘cocking’ of the upper bearing. Just enough to produce a natural tendancy to run straight. I have plenty of bearings now. One of my next objectives will be to take the extra bearings I have to an expert bearing distributor and see if a higher-quality bearing is available in the same dimensions. Mainshaft re-installed for the umteenth time.
After all that work, the main shaft finally looks like it’s running true. The dial indicator is still picking up some movement, but it’s about 1/2 or perhaps less than it was originally. I think I managed to take at least a little play out of the main drive system, and that makes very hopeful for some major flight improvements. Rechecking main shaft runout.
Taking all these parts off, I think it wise to re-check the swash plate level, just in case it something got bent, twisted or otherwise tweaked. Placed the 450 swash leveling took on the plate, and it was dead on! I ordered the tool from XHeli.com (it’s an EXI too) for around $3.50. Well worth the investment. When I checked my ‘by eye’ leveling with the tool I found I was pretty far out. Sure it’s a fair bit more labor to tear down the head to use the tool, but having such a core component as close to perfect spec as humanly possible seems like a wise use of one’s time. Maybe it’s not, but I did it. Carefully re-checking swash plate angle with swash fixure.
Having conquered my fears of the main shaft, time to rebuild the rotor head from the swash pate up. First thing I want to tackle is the top of the head, sort of going in reverse order. It turns out my latest blade grip purchase, to replace the broken grip, wss of the WRONG PART. My model is a Version 2, and the parts I got, unbeknown to me, were Version 1. Barely close, certainly not the cigar. Now today I did pick up a full compliment of Version 1 parts. Combined with the plastic Version 1 head ($7.99) and 2 pairs of grips($13.99) from the other day, I should be able to assemble a very tight and very functional main rotor head. My ideal scenario would be to re-use the original allow EXI head (left) instead of the new Align plastic Version 1 head (right). Main Rotor head types. EXI Version 2 (left) and ALIGN Version 1 (right).
It turns out the the V1 head (right) and the alloy V2 original head (left) are identical in width, and the ID of the feathering shaft ($7.99 for three) holes are also identical. The only difference (beyond material) is a more pronounced shoulder in the V1 head. Fit wise though, they tested out (to the best of my abilities) the same! This is very encouraging! All I need to do now is figure out how the V1 head systems is supposed to go together! Confirmation of compatibility. Rebuild is a GO!
It’s about 1:00AM now. No need to work all night on this thing. I’ll pick this another day, maybe tomorrow, maybe I’ll go ride a motorcycle instead.
