Archive for the ‘mod’ Category.

Makita 9500d Cordless Angle Grinder on Steroids

I wanted one for a long time, but getting one wasn’t easy. I don’t think that they were good sellers at all, most of them most likely went to trash several years ago. Anyway, I was able to find one on ebay kleinanzeigen in Germany. Seller told that it is in good working condition, battery was missing, and the shield was missing as well. I didn’t care for the battery, as I wanted to do a Li-Ion conversion. For the shield, I’ve found a solution on Aliexpress, the Chinese sell shields that you can attach to your drill, and then do ridiculous things with it… It was quite easy to adapt one to the Makita.

When I got it, I tested it out with

my existing Makita NiMH battery, the performance was a lot worse than expected, and the motor was pretty worn, or at least it sounded like that. I looked in my parts that I’ve salvaged from cordless drills, and found a matching motor out of a green bosch drill (don’t remember the model, but it was a 12v NiCD model that I got for free because of the dead battery). This one felt quite beefy (strong magnets, compared to the original), and felt like new. I’ve removed the pinions and pushed the Makita pinion to the Bosch motor using my vice.

I’ve built a battery out of 3 18650 cells (Warning: you need to know what you’re doing, you cannot use normal 18650 cells, it needs to be high discharge cells – like the ones used in cordless tools). There’s no over discharge protection, I’m able to handle this by myself, worst case I would have to replace the battery, if  I run it too low.

Makita 9500D Complete

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Grinder Timer for Solis Scala

I’ve built a little timer with 4 preset values based on an Arduino, Relay, Cellphone Charger.

It all fit inside the original housing. Software needs some improvement, by the time I’m only using a hardcoded delay per push button to match one of the 4 bialetti moka makers that we regularly use.

BionX 250HT hub motor bearing replacement / disassembly, reassembly

The bearings in my BionX hub motor began to die at around 6500km, and now completely worn out at around 9500km. The wheel had a lot of play, and power consumption went up by about 30-40%. Surprisingly, I couldn’t find a lot of info on the web.

As always, this is not a complete guide, but I try to point out those parts of the procedure that were not straight forward to me. If you’ve done it yourself and have something to contribute, please do so using the comments function.

Tools / Parts needed:

  • Bearings:  SS 6003 2RS   Stainless Steel 17 x 35 x 10 mm
  • Strain Gauge: Mine survived
  • M8 bolts + nuts or similar, as tool (see below)
  • Freewheel removal tool
  • Spoke key
  • Hydraulic press
  • Bearing puller
  • Straight puller

I didn’t do it in the same order as I recommend here, but I think this is the best order to do it.

First step – Take the hub apart:

Remove the Freewheel

Remove the torque blocker (pressed onto the axle, brake side). Mine was just cone-shaped, but the newer ones seem to have a notch, so don’t try to rotate it, use a straight puller to remove it.

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Remove the spokes on the brake side, this should suffice / I’ve left the drive side spokes in place. Mark the hub, so that you know how to align the halves when reassembling. I’ve used 9 M8 bolts and nuts to actually press on the inner walls of the hub shells. It was surprisingly easy to get it apart by doing so.

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Second Step – Remove the bearings:

The bearing on the brake side covers the strain gauge, which measures torque applied through the pedals. I have read, that this will usually break during disassemble – luckily mine didnt. The bearing came off the axle / stayed in the hub shell. Getting it out of the shell was a job for a hammer + some alloy tubing.

To remove the drive side from the inner part of the motor, we have used a hydraulic press (sorry I somehow missed to take pictures). So this wasn’t easy, and I needed help from someone with the right tools. It eventually came out, and the bearing stayed on the axle.

Removing that bearing is quite difficult, as you don’t have much room below it, to actually use a puller tool. Luckily the mechanic had something like this (with barely enough room to house the cables while pulling):

9082A

 

Third Step – Reassembly:

 

With that bearing out of the way, it was time to clean the axles, place the new bearings onto the shaft. Add new silicone to protect the strain gauge, as well as replacing any heat shrink that has been removed. I then continued with adding the brake / magnetic side, but I’m not sure if it wouldn’t be easier to first push the axle onto the brake side, as there’s no magnetic involved.

Anyway, since I was back at my workshop, I didn’t have the hydraulic press available, and I’ve used my bench vice to gently press the hub halves together (lots of rotating / small steps were involved).

Add spokes, true the wheel go for a ride.

Conclusion:

It’s running smooth again, so it was worth it. It took me about 5 hours to do it, If I’ve had the right tools from the beginning, it would have been much less. So if you want to do this, be sure that you have access to the right tools.

Hugsby P31 Disassembly / Driver replacement / All flood MOD

In case you’ve ever wondered how to disassemble the Hugsby P31, here’s how it goes:
IMG_0956 IMG_0959 IMG_0960 IMG_0961

I did that because of a malfunctioning driver, and while i was at it, I’ve replaced the reflector with an all flood TIR lens. This makes the little Hugsby a perfect near field flashlight.

Eberspächer heater 24V to 12V conversion

The previous owner of our boat installed an Eberspächer Air heater, which was meant for a lorry, and therefore 24V. Our boat only has 12V Batteries / Alternator. As far as I know he used another battery in series with the auxiliary battery to power the heater, but this battery obviously wasn’t charged when using the heater – I didn’t like that solution, the heater wasn’t used for about 10 years, and now I’ve decided to build a solution.

DSC00040

 

Idea:
The heater has a small controller unit + the heater itself. My idea was to find a 12V to 24V step up converter, and run everything on 24V. This didn’t work out, as I didn’t find an affordable 12V to 24V converter, the one I bought said 150W output power, but that just isn’t enough for the initial glow.

2nd idea:
I thought, why not just replace the glow plug, with a 12V version (didn’t know if it exists back than), and use a relay to switch a 12V line with the 24V from the controller unit.

Doing it:
At this point I’ve decided to unmount the heater, as i needed to find out what kind of unit I have, and which glow plug I actually needed.

What I found was even better:
There’s a huge resistor (or call it a spring) in series with the glow plug – the glow plug is actually a 12V plug, you just need to rewire it to not use the resistor, and install the relay as mentioned above (I obviously don’t know if this is with all the Eberspächer heaters, but it’s worth looking).

Resistor:

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Open controller unit:

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Controller unit with attached step up converter + relays:

 

 

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Close-up of the modification:
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The yellow line goes to the glow plug (already connected directly on the picture, the yellow line in the background goes to the resistor and back):
DSC00041

Charging a Thinkpad using a Dell AC adapter

When I recently bought a used X60s Thinkpad, to replace my even older x40, this also meant that I’ll need to replace my ~6 AC adapters that I have in all the locations where I could possibly want to charge my laptop. Buying 5 more adapters was not a solution as it would have been to expensive. At work we use Dell laptops, so I have access to as many AC adapters as I could possibly need.
The Dell adapters are rated at 19.5V whereas the Lenovo adapters are 20.0V. That isn’t an issue, so it was looking good. The connector looked very similar, however it doesn’t fit.
Now one option would be replacing the connector, but I found a better option:

Removing the modem’s RJ11 (or is it RJ10, doesn’t matter) connector, and installing a Dell DC jack looks way better in my eyes. So this is what I’ve done:

After removing the shield that holds down the DC jack + modem port, I’ve figured out, that there’s just about enough space to place the dell jack (out of a docking station) where the modem port used to be.
After some thinking, I’ve decided to drill two holes and solder the ground pins of the DC jack directly to the shield, this holds the whole jack in place, and also provides ground connectivity – one less cable.
To connect the + I’ve added some copper wire which connects to the + terminal on the original Jack.

You should be aware, that the center pin isn’t the + connection but a data line, that lets your laptop communicate with the AC adapter. I don’t know anything about this protocol, but as I found out, it’s not necessary to connect this pin to the dell adapter (and it most likely isn’t the same protocol anyway).

This is how it looks:

V-Zug Adora – Fehler 1 – Temperaturfühler defekt

Kürzlich hat meine V-Zug Adora 55 Geschirrspühlmaschine den Dienst mit F1 – Fehler 1 verweigert. Das Handbuch beschreibt leider nur den Fehler 8 (zugeführtes Wasser zu heiss). Meine E-Mail Anfrage bei V-Zug wurde schnell und kompetent beantwortet:
“Wassertemperaturmessung fehlerhaft” Was wiederum nicht heissen muss, dass es der Sensor ist, aber die Wahrscheinlichkeit ist hoch. Das Teil habe ich darauf ausgebaut, befindet sich im unteren Bereich, an dem man durch entfernen der Front + einer weiteren Abdeckung herankommt. Leider ist das von V-Zug verbaute Teil ohne Typenbezeichnung, die deutsche Konkurenz verbaut ein physikalisch baugleiches Teil, aber wie ich herausfinden musste mit anderen Werten. Erneut bei V-Zug angefragt, die Teilenummer ist: P59013 – mit Versand hat mich das Teil CHF 21.20 gekostet (was ich sehr fair finde).

Die Bezeichnung auf der Rechnung ist:
Temperaturfühler NTC 100K Ohm / max. 100°C Stahlgehäuse
Bei Raumtemperatur ergab meine Messung ca. 140kOhm. Mein defektes Bauteil lässt sich nicht mehr messen (widerstand unendlich hoch).

Gerne würde ich hier eine Liste mit weiteren V-Zug Fehlercodes publizieren, falls jemand etwas weiss bitte über Komentar bei mir melden.

Having a cold beer on a boat.

I prefer having a cold beer when I’m on our boat, but since this is usually on the sunny days, the performance of our fridge (Waeco CF-18) was too weak to cool one down in a short time (temperature in the cabin goes up to ~35° C if the sun is burning down).

I’ve been thinking about some kind of a GSM-based remote control, and actually found a nice product called microguard. The product seemed perfect, relatively cheap, easy to implement, available, but there was no time-out that could be set. Even if I have a separate starter-battery, it was key to find a solution that turns off the fridge after a given time without user interaction. Luckily, the guy who runs microguard was very cooperative, and added a timeout feature for me (and everyone else of course).

The module now turns on a relay for two hours after it’s been called from my or one of 4 other predefined phones. this is a bit on the short side, but I can live with calling twice.

This is how my installation looks:

From left to right:
Charge split diode / Rear side of main switches / Fridge fuse / Microguard module with relays, cables, mounted on an a plastic case / RedBull cup as holder for a Siemens S45.
The Cat5 network cabling goes directly to the voltmeters on the dash, this was made to show the exact voltage without loss due to load on the cabling.

As mentioned before, I have two separate batteries the starter is a traditional lead/acid battery, and the domestic is an AGM type, which allows deep cycles.

This is how the battery compartment looks:

 

The switches on the left are starter / jumper / domestic. This allows maximum flexibility. The domestic main switch actually doesn’t kill the microguard / fridge, so it can be off, and I can still call the fridge.

Balancing the Magicshine MJ-836 Bike Light Battery

There are many reports about unbalanced Li-Ion cells in Magicshine Bike lights. This can lead into overcharged cells, which is dangerous, or at least will damage the cells. The charger which comes with the light does not have any balancing capabilities, the battery itself only has some very limited under/over voltage protection.

To solve this problem, you’ll need to modify the battery (add a balancing connector), and use a different charger, or external balancer. I’ll use my hobby charger, which has an integrated balancer.

This is no complete guide, it needs common sense, and some knowledge about electronics. You should also know, that working with Li-XX cells is dangerous.

If you don’t know how Li-XX balancing works, please read:
http://scriptasylum.com/rc_speed/lipo.html
http://www.rcgroups.com/forums/showthread.php?t=599316
before starting to modify your battery pack.

Adding the balancing connector:

Open up the pack:

The interesting part is the four 18650 cells, remove the top of the pack (shown on the left):

Add a new wire which will end as your balancing connector, this is connected to the “middle” of the pack, the pack is 2S2P.

Your Magicshine Pack should now look like that:

The next Step is to put back the isolation, and bring the balancer wire out of the case. this can be done through the original cable exit:

I’ve added a 2mm banana connector, some heat shrink tube, and a cable tie:

Finished Pack, charging:

test

As you can see, the connections were made as follows:

– from the battery goes to – of the charger, and pin1 of the balancer.
newly made balancing wire goes to pin2 of the charger
+ goes to + of the charger, and pin3 of the balancer.

Trisa Elektrozahnbürste AA Mod

This article is about a swiss product, which I don’t think is very common outside Switzerland, so I’m writing in German.

Als ich mir die Elektrische Zahnbürste von Trisa gekauft hatte viel meine Wahl auf dieses Modell, weil ich weder Platz noch Lust auf eine Ladestation hatte. Das Konzept aufladen und leerbrauchen hat mir da einiges mehr zugesagt. Am liebsten hätte ich jedoch eine Zahnbürste gekauft, die mit einer herkömlichen AA Batterie / Akku betrieben wird.

Letzte Woche ist mir die Trisa aus unerklärlichen Gründen ausgestiegen. Ich habe dann am Ladeanschluss mit einer Zange die Platine inkl. Akku rausgerissen. Eigentlich mit der Idee das Teil zu reparieren, doch der AA gedanke war schnell wieder da. Kurz eine Batterie reingesteckt, passt perfekt, nur findet auf der Vorderseite kein Kontakt statt. Es fehlten einige Milimeter beim Minus-Pol, welcher in der Bürste sitzt. Ein Quadratischer Neodym Magnet mit 7mm Seitenlänge war schnell zur Hand, und stellt nun den kontakt her.

Die Zahnbürste läuft nun perfekt mit einem AA Akku.