The latest stuff done

Loose alternator nut on ye olde Gixxer

This only happens to me.

Riding my old Gixxer (Suzuki GSX-R 750 1985) it suddenly started to sound really bad. Bad in the way of total engine failure. Shut down and transport home on a trailer. The noise seemed to be from the clutch. After draining the oil, the clutch cover was removed. Picture below is of the clutch. Notice something on the top behind the clutch itself?

GSXR 1985 750 clutch.jpg

Aha! Something is not okay.. let us take a closer look. See picture below.

GSXR 750 1985 error clutch.jpg

No, that doesn´t seem right. After some removal (including taking apart almost the whole engine in the frame) the alternator was pulled out. The alternator nut was loose and the washer (27 mm diameter and 2 mm thick steel) was gone. You can also see that the threads on the shaft was dented.

GSXR 1985 alternator bolt loose.jpg

A new bolt and washer was fastened in every way possible with a help from a friend. Loctite, locking bolt and so on. The nut was actually sanded down for the lock to engage securily on the damaged shaft. It will hold. I also had to take of the oil pan to find the remaining parts of the old washer. The washer just fell down to the bottom of the oil pan.. luckily..and was found.

GSXR 750 1985 new alternator bolt.jpg

After mounting it all together with new gaskets and some gasket glue.. it run´s fine again! Yeah!

Bleep Drum - now with midi

I got hold of a Arduino Uno R3, with a Atmega328 (picopower) mounted. So, what to do with it?

A drummachine!

The Bleep Drum looked nice. The schematics and the code is on the site. The kids loves it!



When I actually got around to making a more sturdy front panel, I noticed it had a midi-update! Soon enough, I managed to get the code working (with help from Dr. Bleep and a zipped MIDI-library for the Arduino). Midi input was realized using 6N138, 1N4148, 220Ohm, 270Ohm classic circuit. Works like a charm! Just remember no implementation of midiclock, sync is done in another way which works fine.


The new front panel. The kids choose some of their favourite pictures for the panel.

Generalmusic (GEM) S2R with battery problem

A friend of mine found a GEM S2R. Dead. Battery (internal NiCd) was completely dead and some leakage had occoured. A new NiMH was installed but the unit was still dead. Well, not completely dead. Some strange things appeared on the LCD, as shown in the video below.

I will probably have to clean the are on the mainboard around the battery and replace some IC´s.

The area around the battery is shown in the picture below. The blue-green powder is from the leaky battery.


Great links:

Thread at Gearslutz

Schematics, manual and sound-disks

Someone visiting the abandoned GEM factory