What should we build a bike?
I went to this topic for two long years. Now I can’t even believe that so much time has passed, but his run is implacable. Perhaps Habr is not the most suitable place for such publications, far from IT, but I want those who are interested in the topic to not repeat my mistakes. And, perhaps, based on my experience, someone interested will get something much better than mine. I will only be glad. The topic of electric transport is very popular among IT-users, and for good reason.
TL; DR - in two years, a small team of 2 people (I as a “builder”, and my Moscow friend as the chief designer) managed to design the frame and mechanics of a road electric bike, and also built its first prototype. Actually, on the CPDV - this is the very prototype, yes. Video test pokatushek - at the end of the article.
If you are interested in the story of its creation - please, under the cat.
A long time ago, in a distant faraway galaxy ... In general, it has always been difficult for me to come up with something big that I want to tell you about, well, to hell with it. 3 years ago I brought my life to a rather remarkable community, in which, on the one hand, people gathered together, sober and reasonable enough to think about global changes, and on the other hand, as usual, very lazy and long on the rise. In general, everything came up against a banal fact - everyone spoke, discussed, decided, argued, built intrigues, scandals, investigations, quarreled, reconciled, proved something to each other, but did nothing, absolutely nothing to ensure that ideas global change of life for the better at least somehow began to be implemented.
But, on the other hand, in every community there are good people with similar interests. It was there that I met my current friend and, as it now happened, a hobby partner. Common points and extensive, interesting topics for discussion were quickly found. My friend, like me, has already come to the conclusion about the “righteous inaction” of all those around him, and little by little, like me, he began the process of moving away from active participation in the community. In general, everything was just in time.
One of those old evenings, the sudden idea came to me to create something with my hands, and not just a “something”, but a four-wheeled, self-propelled vehicle. Such a lightning, from constant thought “How long will we sit?” Instantly translating thoughts into the mainstream “Damn! Its cool! This is what needs to be done! Without delaying a second! ”Colin Chapman’s books on Lotus Seven replica construction were found quickly enough, the necessary literature was purchased and I went into great thought, how and what to do, where to start, what tool I needed. By the way, it will be said - at that time I had several screwdrivers and pliers from the tool. All. With such a set, it's not like a car - it's hard to twist two wires at home. Yes, and I myself am never a piece of iron. The most ordinary pogromist
Of course, after a few weeks of active thinking, selecting a donor, designing and modifying various variations of the spatial frame, suspension arms, spacing all systems, replanning, reading smart books that advise you never to take up building something of your own (and I, if honestly, now I absolutely support this opinion, but, on the other hand, thank the monster that I couldn’t find a second one 2 years ago who could dissuade me) I began to carefully inform my thoughts about the need to move somewhere comrade with whom at that moment, we were in touch almost every day and often called up. There were even funny moments when my wife started jokingly jealous of my “Moscow friend”.
Oddly enough, my proposal to do something was met with enthusiasm and we, headlong, rushed into research.
2 Years before release
Our plan was simple to the point of madness - to build something that could be controlled by man and move thanks to his own power plant. Just at the same time, in our team of geeks in the office, similar moods began to wander, the benefit of almost everything - either with cars or dreaming of buying. The wonderful book “Build your own sports car on a budget” fell into my hands, therefore, as a basis, I and Roma (my Moscow friend) chose just such a layout: a spatial frame based on the Lotus Seven roadster, a power plant from any donor, debugging and starting. But, no matter how good our plan may be, the harsh reality every day laid its paw on all our efforts. After we finished the formation of the frame, we selected the right donor, calculated at a minimum all costs, we came to the conclusion that we’ll just not pull the construction of such a serious unit for money. It’s a joke, only hinged heads of suitable strength cost $ 30-40 a piece, and they needed, without taking into account losses, at least 8 pieces.
Another massive problem, which the two of us faced in full growth, we had a catastrophic lack of experience. Now I am well aware of why young engineers were sent to the workshop for several years, working with craftsmen, looking at machines and absorbing production. The reason for this is the banal lack of any skills in the mechanical and thermal processing of metals. On my own, I noticed for a very long time that in the editor, looking at the blanks, there is practically no feeling of the difficulty with which these details will then be manufactured. The whole model seems like a typical cardboard, which can be bent, broken, changed as your heart desires, and the angles, say, 15.28 degrees - easy! How many times after I found myself thinking that I didn’t ask the uncles at the service station for nothing, just to look and try ... Fingers of all hands and feet are not enough.
And the maintenance of ICEs for me and Roma was a dark forest. No, of course, we quickly enough found the necessary theory and literature, but there was absolutely nothing to train and look at the results. At the same time, it frightened me that, acquiring basic knowledge, the subject area for each engine is a separate song developed over the years, and we absolutely could not afford it. Too hot heads and young hearts, we needed a result, and the faster the better!
One of the first samples we wanted
Of course, almost every day we were in the phase of an active search. Crazy heads even considered any exotic type of hydrogen cells ... And it was at that moment that one of my comrades threw me a link not evtv.me. The electric drive produced the effect of an exploding bomb in our heads. Without even listing all its advantages, we, first of all, were pleased with the minimum of necessary details, the minimum of maintenance and the possibility of Direct Drive, i.e. direct connection of the engine to the rear axle without a box, only through the gearbox. And the two of us were very impressed. Nobody knew that after that we would stop thinking about ICE and get infected with an electric disease until the end of our days. But this disease, in fact, is very pleasant.
But the problem of price and the problem with batteries added to this has not gone anywhere and has not disappeared. We still lacked money and experience, and something had to be done about it. Having found several calculators in the network for the traction calculation of transport, we quickly found out that, depending on the weight and cross-section of the transport, the required power and moment differ quite significantly. And in some magical way, both I and Roma came to the conclusion that you need to start completely not from the car frame and not from the roadster. To get the most elementary experience working with metal, we decided to assemble a reverse trike. They abandoned the spatial frame, leaving a flat truss, they decided to test the first samples with ordinary gel batteries from the UPS, quickly found the “suitable”, as it seemed to us,
We spent a total of several winter and spring months on all the preparatory stages, and by April of last year we reached a project that was ready for about 80% of the base necessary for construction. It remained the case for small.
Let the show begin
A month went in search of a suitable garage. As a result, they found a two-story box for two cars, however, without any repair. Naked sand on the floor, heh. However, we are not very demanding and this was enough for us. We purchased a welding machine and flux-cored (fluxed) wire to it, and for another month or more I buried myself in a shallow garage design, arrangement, assembly of all kinds of tables, chairs, purchase of the necessary tools and consumables. In general, our kit, assembled at the moment, is not so large in volume. Drill, small grinder, sharpener, pipe cutter, welding machine, Chinese "milling" hobby machine and hand tools. At the same time, one of my friends gave me his old sofa with an armchair and a coffee table, so that even a small soft sitting area appeared in the garage. In the same month I studied welding. YouTube is truly a great thing for this, so many educational materials and people who are willing to share their practices on video, I probably could not find anywhere else. I’ve been told for a long time that at the core of their training in labor specialties and tyrotrub are just made for each other, that either you watch a video or you are looking for a friendly and tedious master who will be ready to mess with you until you learn at least something, but I waved it off. And he turned out to be wrong. On a personal example, I myself have confirmed that you can cook in video tutorials in the least. either you are watching a video, or for a long and tedious search for a benevolent master who will be ready to tinker with you until you at least learn something, but I brushed aside. And he turned out to be wrong. On a personal example, I myself have confirmed that you can cook in video tutorials in the least. either you are watching a video, or for a long and tedious search for a benevolent master who will be ready to tinker with you until you at least learn something, but I brushed aside. And he turned out to be wrong. On a personal example, I myself have confirmed that you can cook in video tutorials in the least.
Along the way, Roma and I completed the Mit course 6.002 and became a little more savvy in the matter of electrical circuits and load analysis of all electrical insides. The electrical circuit itself was simple - 8 batteries connected to a 4s2p, 48V, 18Ah, 18kg unit, all this is fed to the input of the controller, and the output is a connection to the engine and accelerator handle. The engine itself, the controller and everything that was attached to it - the Korean kit for converting a bicycle into an electric bike (http://www.cyclone-tw.com/order-1chain.htm, at that time we took the most powerful one available - 1200W / 48V, now there is a version on 1650W). For testing - that’s it. Since the end of June, we plunged into the construction of the frame, ordering turned parts (by the way - an insanely expensive thing compared to the price of iron, then), teaching all the wisdom of cutting, welding, steel processing in all possible and impossible manifestations, preparation of improvised tools and devices for myself (both desktops with steel worktops in the garage are welded by me). A suitable metal with delivery was found at one of the metal depots with delivery by a cheerful driver Ashot on a broken-down gazelle.
Towards the end of construction, they came to the conclusion that flux-cored wire is complete, expensive flippers and ug, it is better not to cook anything with it, or if there is absolutely nothing (in the field near the birch from the generator). I bought a refilled carbon dioxide bottle from local uncles in the garage and agreed to bring it to my garage. About how my friend and I dragged him upstairs to the second floor - this is a separate song, which I had to crank out this year as well. Pleasure is not the best. For a long time I suffered with steering - it was not possible to accurately and correctly cut and then weld the steering knuckles and for almost a month I was waiting for the cantilever bushings on the "front" axle. And after that, I was looking for a bicycle shop for a long time, in which they are spoken. But I still earned some respectful views,
Along the way, I had to solve minor conflicts at home, I managed to pretty much feed my wife, since I spent almost the whole weekend in the garage. Now I am sincerely grateful to her that for the time being she tolerates all my tricks and steadfastly endures my absence at home. Everything spun tight enough, and I no longer paid attention to a billion minor problems. If before it seemed to me that driving to the market at the other end of the city and buying some necessary trifle was a feat, now I have started the trip almost every Saturday. Constantly there were not enough fasteners, bolts, nuts, small sheets of iron, bits, wire, wood, pipes, rods, adapters, fasteners ... This list goes on and on. As soon as you start to do something - always, always some little things will not be enough and you need to either put up with it,
The steering structure then caused the greatest confusion for me. I learned how to cook exactly, and the steering assembly process was more like hell flour and persuasion of a bull to give birth to a kitten, but we did it. With the brakes, it was decided not to bother too much and the Avid Juicy 5 pair settled directly on the front wheels, mounted directly on the steering knuckles through the plates welded to them, the suspension was absent as a class. The not-well-thought-out design of the engine mount assembly caused me just a monstrous storm of emotions, after which any mistake in the project I began to firmly associate with the phrase “Sharpener modeled, #% & # @!”. The decision to use the BMX wheel turned out to be a mistake - the engine torque was not enough with a gear ratio of 7/9 teeth, so that the driving dynamics were at least somewhat acceptable and we did not burn the engine, so we had to change the rear hub from the BMX driver to a regular overtaking clutch (freewheel) with 24 teeth. Having increased the moment in this way, consider almost 3 times, we were able to achieve acceptable results. The final chord was the welding of the stand for the chair, the installation of the chair itself and the final assembly and connection of the electrical circuit of our device.
On September 22, after an evening ride attempt, a slipping of chain links was detected under load. The next day, in the morning, I quickly milled a mount under a chain tensioner from a piece of steel corner, we successfully welded it and went for a test. And now the test was a success.
A couple of days with Roma, we were just in euphoria. What we have been discussing, designing, remodeling for so long, because of which we have argued and quarreled, has finally begun to live! It was simply indescribable. The whole next week I devoted to fine-tuning and skating in the surrounding yards. Frightened grandmothers and mothers walking peacefully with stupid polls on how to get to the school stadium, or where you can turn around. But it was very fun and unforgettable! I don’t even know what it looks like ... The pristine joy of creation, when it starts to work what you thought about for so long and what it took so long, pride in the work done, albeit not very high-quality, but strong and whole, the pleasure of simple pokatushek, adrenaline explosions on the slopes ... Uff, you can describe the whole range of emotions endlessly. But you need to try it, no words will convey that
Brace yourself! Winter is coming!
Gradually, we nevertheless returned to their normal working course and, as a result, found a very, very large number of problems that practically put an end to the further refinement of this particular frame. First, and most importantly - just a huge weight. The profile pipe 60x30x3 was not just heavy - it turned out to be monstrous and slow, it was very difficult to raise the frame itself, and when the batteries were added, write was lost. One I even lifted my trike by the tail with an effort. We tried, as much as possible, to compensate for the lack of suspension with a double layer of thick foam rubber on the seat in a faux leather cover, and this helped. At least the fifth point and back after pokatushki hurt not so much ^ _ ^ Well, the problem is in the power plant. She was clearly not enough for that weight, the engine overheated and turned off several times,
The final characteristics that we have achieved:
Max. speed: 40km / h
General description of the design
From this moment begins the story of the bike on the CPDV. One evening, after another re-planning of the frame and when we added the suspension and were actively looking for a new power unit, I came across a link to American Stealth electric bikes. “Roma, damn it, I have an idea! We can freely make the same bike in just a couple of months! And I will be very torquey transport ride to the market. I need to do this, by golly! ”Of course, Roman, already then quite strong on trikes and having learned past mistakes, took my idea without enthusiasm and was generally against it, but I insisted on my own and I managed to convince him to do a sketch project for me . And our goal, in the end, was not just building a bike. We decided to build a bike powerful enough to
By this moment, I had buried quite a bit in reading endless-sphere.com and already knew very well what exactly we needed in terms of the power unit. Despite the sky-high cost, we opted for a solution that, at the moment, is the most powerful of the available for bicycles. We decided to build our bike on the basis of the Greyborg Cromotor Motor Wheel, aka Hubzilla. The mk2 version, which was on sale at that time, was announced as an engine with a maximum constant power of 6KW and a peak power of 10KW. In general - for the eyes. For greater discrepancy, we decided to try the Chinese NCR18650B batteries, fortunately, I went to a reliable supplier.
We put off the idea of making a trike fairing until better times. The unheated garage absolutely did not allow doing anything inside, just the wildest cold. Therefore, all winter time we were engaged in planning and fundraising.
Around the winter, Roma and I were visited, it seemed to us, by a brilliant idea - what if we take it, and the battery blocks are not just ordered, but printed out by ourselves? 3d-printers are already quite stable and common thing, printed ABS-plastic is strong enough for our loads. In general, why not? Of course, the one who does nothing is not mistaken, but now I know for sure that I will contact RepRaps only because I studied their design with my hands up and down. But I would not advise starting my acquaintance with printers, being aimed at a specific result. Will not work. Just as it did not work out for me.
Having purchased an assembly kit at Blomker Industries and assembled our MendelMax accurately enough almost from the very first days of printing, we ran into problems that we have not been able to solve so far. Any large workpiece strove to stick out at the edges and bent into an arc. Our blanks were long enough - 176mm long, and it was the holy faith in the “work area” that brought us very much. Details deteriorated, even when glued with cyanoacryl directly to the table on which they were printed. At the same time, it’s not a quick one, it’s not very pleasant to spend a few hours to get a marriage in the end. I earned unfinished printing syndrome and started waking up at 3-4 in the morning, checking the printer, and went to bed further. All weekend passed before this bad piece of iron in the hope that the next change in settings would help something, but all my hopes and tactics, advised on forums just didn't work. The printer, as it was printing samples that could not be used, continued to print, completely ignoring all my efforts. Along the way, I managed to completely grind the bolt with the thread in the extruder, soldered the contacts several times, spent almost 2 kg of ABS plastic, caught software glitches for macros ...
One of these glitches put an end to further attempts to use the printer. One night, when I got tired of waiting for the result and went to bed, my printer turned on the table to heat the workpiece and ... Pronterface fell into the bark. At the same time, the printer itself stopped printing, but did not turn off the heating circuits. In the morning, I sat down to count the losses. The losses turned out to be mainly electronics - one of the stepper motors jammed from the temperature, 2 control loops burned out, the extruder turned into a fused mess. An Epic Fail worth nearly $ 900.
The remnants of the printer went to the cabinet, but this failure did not stop us. Starting in March, we began to collect all the necessary components, since part of the design and general calculation was already almost completed. We managed to buy an engine, bought all the necessary batteries in two batches of 100 pieces with a difference of 2 months, waited for the controller to arrive from the United States, and at the end of August, finally, it was time to assemble the entire kit that we purchased. During the same month, we waited for a wide rim and rubber for it from Germany and for about another week we were looking for a master who could correctly spice the engine onto the wheel. More than a dozen craftsmen in different stores simply refused, motivating it with anything. But I did find a store where they helped me, even if it cost 3 times more than usual, but I was ready to pay more if my wheel were spokes. From these same masters he subsequently acquired all the parts for assembling the steering and assembled the front wheel.
The remaining bicycle components (fork, shock absorber, brakes) were purchased through the x-bikers.ru flea market. Problems with the purchase and receipt did not arise in principle, but rather, it is the merit of those who sell.
In general, everything was assembled and I began to spend more days off in the garage. Having picked up the entire groove (the steering glass and the sleeve under the bearings for fastening the pendulum), I marked and cut all the segments under the frame, welded it, set to work on the pendulum ... And after welding I realized that the engine just could not fit in. We literally made a mistake by 5mm, without taking into account the flanges for the overrunning clutch and disc brake, and because of this we had to “reinvent the wheel” in a new way. Having discussed the problem with Roma, I carefully cut the pipes, bent each 5 degrees and boiled what I cut, simultaneously adding two stiffeners passing through the weld seam. The reciprocal mount for the engine was decided by the same folding of a 5mm thick sheet. At the same moment, I ran out of gas, which slowed down the assembly for another week or so and the pendulum was completed after refueling.
Having worked out the frame and adding fastenings for the shock absorber, it was determined that the 350x3.25 spring was weak, and something more was needed. Threw an ad on the same x-bikers. A very strange situation, but there are no springs for bicycle shock absorbers at all in Ukrainian bicycle shops. There are only shock absorbers already complete with springs, which, in the presence of amortization on my hands, did not suit me at all. A suitable spring had to be ordered on the kettle (slang name chainreactioncycles.com). But the right spring, thanks to the kind people from the forum, was found about a month after I threw a message about the sale and exchange of springs. She set it up for now.
According to the numerous advice of friends and acquaintances who evaluated the frame, I added additional scarves in the pipe joints to increase strength, pressed the bearings into the pendulum mount and received my axis from the turner, which I then had to finish with a file and 1000th sandpaper, since it was just I didn’t want to enter the bearing assembly as I had planned. It was up to the small thing - to assemble and secure the battery packs. For this, I prepared a small manual welding machine for spot welding on alternating current, successfully tested it and welded all the batteries into blocks of 14 pieces.
Along the way, I purchased a Hyperion 720 Super DUO3 charger, suitable in all respects for all my parameters, in one of the hobby shops, I also went to the daughter of the Zaporizhzhya electronic devices factory and took a test sample of the laboratory power supply unit 30V / 40A from them. After that, I realized that such a powerful power supply needed to be purchased, but during the acquisition I still doubted much. As the first charge showed, the total charge current of 32 amperes is not a joke.
Separate remarks are worthy of American sellers of parts and components. So detailed description of what I get, with all possible and impossible schemes and descriptions, I have not received anywhere before. Not only that, when I ordered the controller - the seller shot a small video with my controller testing before sending it, posted it on the piping tube and sent it to me as a confirmation of operability. I was at that moment, to put it mildly, surprised at this level of service. Upon receipt of the controller, I checked the serial numbers from the video - everything coincided. And, most importantly, the guys selling over the hill are very responsive and ready to help with the problems that arise during the setup and launch process.
During the assembly process, another unpleasant news was waiting for me. No, not even two news. The first, not the saddest, but rather unpleasant one - the nickel tape 5 mm wide turned out to be too narrow and thin, therefore, as a transitional solution, I decided to solder the thick conductor under high current, which gave rise to the following problem - the batteries simply did not fit into the batteries prepared for them forms. Yes, I cut the forms themselves in one of the Kiev advertising agencies from transparent ABS plastic, then glued them together and got a fairly strong structure. All blocks had to be separated by spacers 5 mm thick - they had to be milled to 3 mm so that the conductors could be freely placed and still made it possible to assemble the entire compound.
We found out the second news after we assembled the entire structure in a combat state. I’ll make a short remark about how we came to the NCR18650B batteries. In order not to mess up and not to wash the seat after the first tests, Roma and I decided to start using the engine in the most sparing mode - 48 volts. At the same time, according to the passport, the engine consumes up to 40A on a flat surface and up to 60A for a 10% rise. That is, it turns out that through each of the 14 blocks a maximum current of up to 60A should pass, which in translation to one cell is 4.28A. The maximum allowable current consumption for the NCR18650B is 2C, i.e. up to 7.5 amperes. We had less, which pleased, as the batteries would not undergo significant degradation during operation. But the main ambush was that each of the cells had its own protection circuit, limiting the current through the element to 1, 5A. After the first tests, my friend Dima and I, with whom we often hung out in the garage and who helped me with all my hobbies, felt a clear smell of burned electronics, after which all the blocks had to be sorted out and this protection removed from each element. By the way, on some cells, burned-out circuits simply closed the circuit, dropping the battery to almost zero. I had to replace them from the "repair kit" with 10 cells, additionally purchased in reserve.
At the same moment, I still found a Ukrainian seller of nickel tape, which I was extremely happy about. Literally the day after the order, a whole kilogram of 175x0.1 tape fell to me, which was quite enough to completely cover the entire battery pack and leave the language to connect to neighboring batteries. In general, this is how I assembled this compound by throwing away the spacers and simply gluing the entire plastic box with cyanoacryl.
The final cut
Stages of the final assembly
The first tests passed just a couple of days ago. Just during the final assembly, my friends drove into my garage to sort out one of them RS-ovskuyu plug, and at the same time see what happened.
Version 0.12 alpha did go, and went very cheerfully. About the same as I expected. Not very playful, like a motorcycle, but for training and primary tests - just perfect. We did not reach the year since the launch of the previous prototype. It didn’t work out in a couple of months, but it was already and it didn’t matter. The main thing is that we did succeed, our bike went on its own, and after testing and running through the garages all Sunday I walked as happy as an elephant after a good washing and polishing.
As a summary - electric transport can and should be built, tested and look to the future.
Approximate performance characteristics that we now have on hand:
Weight: about 50kg (engine weight - 14kg, battery weight - 12kg)
Power reserve: 80-100km (about 45Ah with recovery)
Max. speed: up to 50km / h on a flat surface
Suspension travel - 160mm at the rear, 120mm at the front
Batteries: 200 NCR18650B, about $ 1700 in two deliveries from China
Engine: Greyborg Cromotor Mk2, $ 565
Controller: LYEN 18Fet, bought with it programmer cable and accelerometer - $ 265
Fork: RockShox Argyle 302 2009, new, $ 280
Shock absorber: used Fox Van R $ 130
Brakes: Avid Elixir 5R, front + rear kit with rotors, $ 180
Rear wheel: order on custom-cycles.de, instead of with knitting needles $ 200
Front wheel: $ 80
Steering equipment: $ 60
"Sources" of the frame: $ 50
Turning Details: $ 120
Cycle Analyst: $ 170
Charger: $ 375
PSU for charger: $ 300
It seems that I forgot nothing.
The final cost came out, to say the least, sky-high. Spouse is better not to show ^ _ ^. And all this is due to the fact that we tried to take the best of the available and did not stop at half measures. There are many ways to make a bike cheaper and more practical, but for this you will have to adjust the performance characteristics - reduce range, adjust power. In general, to move away from the original idea of an “ultra-long bike”. And this, one way or another, will have to be done, since you don’t even have to stutter about such far-reaching plans.
An inquisitive reader has already managed to look into the post tags and see Open Source there.
And not in vain. Pondering for a long time with Roma our plans for the future, we came to the conclusion that it is still worth taking a course on openness and free distribution.
Therefore, after the final, the so-called The "pre-production" sample will leave our penises - we will publish all the drawings, calculations, assembly diagrams, plans for our welding jigs and the entire process map on github under the MIT license. All this will be abundantly flavored with our advice and remarks, so, I think, putting together a replica of such a bike in the garage on the knee will not be a problem.
At the moment, our small team is testing what happened. I need to get out on a flat surface and check the range data, set up the Cycle Analyst, glue the fairing from fiberglass and protect the bike from rain. The plans are a little further - assembling a new frame, moving the batteries below, training in argon welding, replacing batteries, increasing voltage and changing the main components. At least I want to put a fashionable two-sided fork. Without her, it’s not at all good.
And yet, yes, I cannot now objectively evaluate what we have achieved. So far, we have received a very, very expensive toy that needs refinement, like air. But we have something to build on, and it makes me very happy.
If you read up to these lines - thanks. The sheet was impressive, yes. But I really wanted to share my joy with the geeks, whom I read with pleasure every day. Once again, many thanks to my partner Romka, although you are bad, but very cool, and to my wife Lenochka for titanic patience.