Floating battery

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Since the only one in the family who didn’t have an electric bike was my wife I of course had to build one for her as well. When asking what the battery should look like the answer was “It should look like it’s kind of floating in the frame”.. Well..

I had to use the mill for this one, milling 10mm acrylic spacers to hold the edges of the battery pack. Since my beloved wife doesn’t do much offroad racing this’ll be plenty strong enough.

Designed a box shape that follows the frame with an offset. This is a test fit of the outer casing, seems quite ok.

So, after welding a 13s5p pack of LG MJ1 cells the bike turned out quite ok.

The bike is propelled by a BBS02 motor using an eggrider display and performs real good. This motor previously had a problem with the controller where it would say the battery was depleted when it was almost full, but with the eggrider this seems to work just fine.

El Avant: Rivningsarbete

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Så..

Efter att ha spelat in avanten i garaget igår så blev det till att börja riva ikväll. Började med att slita upp maskinen på lyften så att vi senare kanske får en mer ergonomisk arbetssituation..

Strippade även av diverse plast som kommer vara ivägen för fortsatt arbete.

Efter detta började jag bakifrån med allt vad avgas heter..

Väck med sitsen så att motorn blir enklare att komma åt..

Efter att ha plockat bort batteriet och bränsletanken (som visade sig ha tre hål i sig, utöver de hål som ska finnas) insåg jag att man kan skruva loss hela vänstra sidan på maskinen, så så blev det..

.. och efter lite bök och bråk med skumma finska lösningar så var halva jobbet äntligen gjort!

Bensindrift no more!
Jag kommer riva motorn för att inspektera vad som gått fel och vad som gått sönder med den senare, men det blir ett projekt i sig. Först ska Avanten igång med el giganto elmotor, så vi fortsätter:

Det verkar som att motorn samlat på oljeblandad gegga och här blir det en extra god röra då det är både hydraulolja och motorolja som blandas med lera och grus.. Resten av kvällen tvättade jag, både maskin, verktyg och kropp.

Så var bensinmotorn urplockad. Nu ska motorplåten få sig en drös nya hål, ett nytt remhjul för 8M rem ska införskaffas och sedan ska hela kalaset monteras ihop igen..

Nä just ja, jag måste ju få kontrollern först, och DC-DC omvandlaren.. och reda ut avantens elsystem.. och BMS:erna, och displayerna till BMS:en.. sen ska hel.. jaja, det finns kvar att göra verkar det som.. På återseende!

El Avant: Maskinflytt

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Så var första steget i elkonverteringen av avanten slutfört:

Avanten är, utan att motorn gick att starta, förflyttad från förrådsskjulet till garaget.

Det var ingen enkel uppgift, det krävdes både spännband, vajerspel, block, en tretons domkraft och två gubbar för att spela upp maskinen på släpen. Hjulen går inte att frikoppla och motorn går inte runt, så den är smått tungrullad.

Nu är den dock på plats innanför dörrarna och nästa steg är att påbörja rivningsarbetet!

Elkonvertering Avant216

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Så, precis lagom till första snön i år valde vår kära Avant 216 att tacka för sig. Den har gått lite dåligt under en tid och nu verkar vevlagren ha tackat för sig och gått i pension.

I normala fall hade jag bytt vevlager, fixat veven, eventuellt bytt kolvar, foder och ringar och gått igenom allt som behöver fixas på motorn – men det är så mycket som inte fungerat bra på den 16hk bensinmotor som sitter där att jag varit sugen på att byta ut den ett tag.
När jag fick priset på en 20hk dieselmotor som är en drop-in ersättare så bestämde jag rätt snabbt att avanten blir eldriven (har varit sugen på att elkonvertera ett tag, men det känns bortkastat när den fungerar.)

Kalkylen såg ut såhär:
20hk dieselmotor: 46000:- plus moms och frakt
vs
Elmotor med kontroller och reglage: 15000kr
2 uppsättningar batteri (2.2kWh 96V nominal 300A): 10000kr
BMS: 4x1000kr

Så även om jag behöver ett betydligt större batteri så kommer detta gå att räkna hem.. (Jaja, nu ska vi inte jämföra med vad ett vevlagerbyte skulle kosta)

Så, efter att ha letat och gjort lite efterforskningar hittade jag en motor som troligtvis duger. Sedan tog jag den motorns storebror, kollade att den borde rymmas, och drog iväg en beställning.. och idag damp den ner i .. garaget..

Detta är ett monster från QS-motor..

De specar den till 8kW, vilket är lite lustigt då den ska klara 16kW kontinuerligt..

.. och kunna mata det dubbla, 32kw, i 10 minuter..  (ja, min hand ligger på motorn)

En matchande kontroller är beställd och borde dyka upp till veckan, då kommer en uppdatering. Sedan behöver jag få undan lite prylar från garaget för att kunna dra in den döde avanten och påbörja ombyggnationen.. Detta är ett projekt jag ser fram emot massor, har redan börjat skissa på batterisetup men måste få mäta mer på avanten för att kunna bygga ett batteri som passar.

Lite intressant är det att den lilla motorn, samma som jag har på min cykel, är specad till 5kW (det var 7.5kW när jag köpte den) medan den stora är 8kW.. Någon har räknat lite knasigt kanske..

Fortsättning följer.

Quick update

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Just a quick update.. The hand is still useless on its own but I’m at version 3 of my “exo-skeleton”..

The wrist support is printed using PETG with a compliant design to let me bend the wrist a bit. The finger risers is PLA, shaped like a J to not stop the bloodflow and the “springs” are 1.5mm piano wire..

This one works great and is pretty comfy too. Next version will be “full cyborg” using electric servos and a laser – if it comes to that. 😀

Nerve, nerves and paralysis

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So, a while back I sold my Canyon Nerve AM to a friend who wanted to start riding. I myself, as you sure know, had upgraded to a downhill bike and the nerve was just sitting in the garage.. Well, turns out it didn’t take and last week he reached out asking if I wanted to buy it back.
Since my kid is growing at record pace I guess his Giant Glory is going to be too small come spring so what the heck. Next ebike project will be rebuilding the Nerve with a BBSHD and a large custom battery made-to-fit..

Well, from one nerve to another. Last week after doing some heavy lifting it seems I damaged my radial nerve in the right arm leaving my hand semi-paralysed. Bummer!

Went to see a physician the day after and have never laughed so much at a health care facility. Almost felt like being in an episode of dr House when she called hand surgeons, a german expert, had other staff come laugh at my hand – all to get the diagnosis right..

Well, since my hand is all sloppy I really can’t use a regular computer mouse anymore. Had to argue a bit to be allowed to keep doing my dayjob but after that was sorted I really needed to find a solution to the mouse problem..

I know there are those ergonomic vertical mouses so I ordered one of those. The angle was sorta right so it kind of worked but since I cannot open my fingers I kept pressing all the buttons all the time – not ideal.. So I had an idea..

Started out with an ad-hoc prototype just to test the idea.. It worked well enough to let me CAD the first draft of a solution..

This worked much better but since I need a brace for my wrist not to over-stretch it I needed more.. To be able to import my hand into CAD i needed some reference measurements..

Some time CAD:ing later (wow, everything takes SOO much longer when only semi-able to use the right hand) I have a version 2 prorotype..

Using the regular mouse is a no go but I’ve been able to tweak the brace so that I can effortlessly use the most important functions of the mouse: Movement, left- and right buttons and the scroll wheel.

The only problem now is that it’s a bit on the bulky side and a bit uncomfortable to wear.. but the hand is mostly numb anyways.. 🙂

Since I work mostly underground and my normal brace is made from fabric that gets dirty fast I need something else at work. So yesterday while insulating the house I made a makeshift brace from leftover parts..

It worked flawlessly which lead me to design the v2 workbrace:

It’s a bit sturdier and 100% plastic, should fit inside (or outside of) my glove and if it breaks I’ll bring a spare. 🙂 Got it on the printer right now. Going to print this in PLA and PETG to test which is better and more comfortable.

And yeah – I’ve always wanted one of those cool mesh-braces when I’ve broken bones but never got one, so this is a perfect opportunity – right?

Had my daughter help me make a 3D scan of my arm. I’ve just got to figure out how to get the scale right and then we’ll start having some fun. I just hope I get to finish this before my paralysis gets so much better I won’t need it..

Yeah, the last physician I saw told me the nerve probably isn’t severed which means I probably will get full function back. Regarding the severity of my paralysis it’s probably going to take several months tho.. good times! 😉

Snap-on headlight v1.0

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So, autumn is here and with that the total darkness in the evenings.

To be able to ride we need a light source that’s easy to mount and remove on the bikes.. so this is the first trial version.

I bought a couple of small LED-lights on amazon and designed a mount that snaps on to the front shocks on my bike..

Printed and test fitted it looks something like this.

The holder for the light is adjustable both height- and side-wise. It snaps on perfectly and sits pretty snug on the shock..

If testing shows that it self-adjusts I’ll redesign the mount with some TPU inserts to make the mount harder to twist.

The battery case fits perfectly on the other side..

Welded a battery pack from three 3,5Ah LG MJ1 cells to get a 12V source. I had bought a stepdown that’d work with the main battery but I found no good solution to connect it to the pack so this’ll have to work. For the next bike I’ll be able to connect the stepdown to the charging port so that’ll be what my son will use. My charge port is a bit special so connecting to that can’t be done in any good way that’ll not interfere with my legs when riding..

This is the finished kit..

.. mounted on the bike. I had to turn the battery pack outwards a bit to not limit the turning of the handlebars. Next time I’ll put it forward instead which works just as good.

So, the result then?

Well..

The headlight is pretty powerful but it is a bit too narrow. Since it has a – shaped profile of the light it’s also limiting the height of the light which isn’t perfect for riding..

Took a spin on the road and a trip around the local ski track and here the height of the light beam is really hindering. Going 40km/h in the darkness is very tricky with this limited light.. Since I know the track pretty well it’s possible but going around corners means turning into total darkness.

So – conclusion: It works but a wider beam would be better. Will look into modifying this light to cast a wider beam.. The mount however works flawlessly with the light sitting firmly in place and not moving when going over rocky and bumpy sections. So, with a modified or other lamp I think this will be perfect!

Combining this with a helmet light would be perfect so that’s probably what I’ll do. I’ll just have to figure out some good way to mount a battery pack on my neck.. or somewhere close to the helmet. 😉

 

Trollface box

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So, after having posted on social media about the boxes I built a finnish friend reached out to me asking for help in printing a box. He already had a design and proper 21700 batteries so I just threw something together in CAD and printed it out for him.

When I asked him for a logo to use he sent me a picture. I don’t know if he was serious or not but this is how it turned out:

He was happy with the result and the fit in the frame was more or less perfect.

Didn’t get many more pics of this project unfortunately, so this was just a quick update.. there’s still much more to come so stay tuned!

Mondraker battery build

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So, a buddy from Italy reached out to me. He had seen what I’d built for myself and my family and had a super nice Mondraker frame for which he could not get a suitable battery case. Since it’s almost impossible to ship batteries abroad I offered to make him a case for him to weld his own pack in.

Same method as before but he wanted to fill the entire frame “triangle” on the bike with the pack, so we made quite the large compartment for the BMS and wiring. This was also done to minimize the total width of the pack and centering it on the frame.

Here you see all the components. The cell frame, the joiner, the sides of the box and the TPU gaskets to make it waterproof(er).

Since my buddy didn’t want visible zipties to mount the pack to the frame we devised a mounting system using CNC milled aluminium brackets to mount to the bottle holder holes and two additional holes he would make.

The brackets are made to make the plastic case survive the forces from the M5 screws holding it to the frame.

Perfect fit. The bit wierd method of having theese brackets under the box is so we could use the cellframe/joiner method to make it. The brackets are mounted on the frame and the box slid over them before putting the final side on the box. That way the box can be removed without tearing up the cell welds. 😉

To be able to make the logo more visible I printed white infills.

This box is now in place in Italy enjoying the sun and I got a picture of it all mounted.

Beautiful bike and the battery fits perfect in the frame!
This was quite an interesting build. The design my pal had already done and he had quite specific requirements for the mounting system and how he wanted it all to look. Turns out he knew what would look awesome in that frame!

Battery for my sons bike, 2 generations

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So, of course when I ride an awesome ebike the kids want one too. First of all I had to build one for my wife but that’s just a standard bike with a hailong pack. This is what I was riding at the moment:

Generation 1, 2020

But since my son was a wee bit short (10 years old) the bike we got for him could not fit any standard battery, so this was actually the very first totally custom battery I built.

Started out by making a dummy frame just to see how many cells we could fit in his frame and to get an idea of the shape of it:

Made cell frames and fit K-power 2500mAh 12,5A cells in there.

Installed the second frame and welded it all together.

As you can see this is a 13s5p pack yielding a whopping 48V with 12,5Ah and a total power output of 62,5A. This is by far enough for a small 10yo child. Only once did he ever run out of juice with this battery and that was after a 40km+ ride starting out with a half full pack.

Kapton tape to insulate the pack and then it was just a matter of mounting the BMS and putting it all on the bike.

Printed the case on glass, that’s why the sides of the box is so reflective. That didn’t last for long with the abuse the kid put this bike through though. 😉

Generation 2, 2021

Skip forward one year. A couple of crashes later he has grown quite a bit taller and now enjoys following me on the harder offroad and downhill trails. Never complaining I can see how he suffers from the stiff rear end of the green Merida bike and having bent both the rear rim and the front fork quite badly I thought it was time for an upgrade.

I found a used Giant Glory 8 in small size for cheap, just some 350km away, so I made a roadtrip and picked it up. This frame looked like a perfect fit for an electrical conversion!

After some careful measuring (and a lot of not so careful grinding on the frame to fit the BBS02 motor) the normal process started.

Cell frame with cells. This was actually the first time I tried the frame-joiner-frame pack type due to a total lack of space in the frame. This time we wanted more speed so we decided to go with a 14s4p pack to get a 52v battery. The problem using only 4 cells is the low capacity of the pack so this time we built it on LG MJ1 cells with a 3500mAh capacity and 10A continuous power output yielding a 52v pack with 14Ah capacity capable of 40A output. This is more than enough for the BBS02 and even after upgrading to the BBSHD (after messing up a controller) the battery doesn’t even sweat power wise.

The joiner is installed over the frame with cells. Take note on the cell configuration. I’m trying, even though it’s sometimes hard, to get as good a serial connection as possible throughout the entire pack. For a 40A pack like this I want to get at least 4 or 5 serial connections with my 0.2 x 8mm nickel strips which means I often have to put several layers of nickel on top of eachother.

Other side cell frame put in place. It’s such a tight fit that I sometimes have to put the pack on the floor and use my weight to evenly push the frame onto the cells.
Welding and adding insulating kapton tape on the side of the battery before turining it around to weld the other side. I take real good care not to accidentally short the pack out. Shorting it out is REAL unpleasant and bad for the cells too..

After insulating the pack more with tape which I like to put between the cells and any leads running over it, I add the BMS to the side of the pack and then close it all up.

He did not want any logo on the side of the battery so this is how it turned out. Works flawlessly but 14Ah is a bit on the low side with the type of riding we do now so for next summer we’ll revisit this bike and somehow fit an even larger pack on there.