Have you bent your SF2500 motor shaft? Read on to find out how to change the shaft to a stronger 3.2mm diameter.

You will need access to a good lathe, bench vice and maybe a tap & die - try not to use your hammer!!

The part you will need to build is shown below:

I was told the shaft could be 'pushed' out and replaced with a single 3.2mm drill blank - this was not the case, the original shaft has numerous machined surfaces and is threaded into the steel magnetic section. I found this out after pressing the shaft out with the vice and stripping the thread. This did limit my repair options but overall had little effect as it was unlikely I could have matched the thread type anyway.

To open your motor you will need to break the adhesive holding the carbon fibre case to the aluminium end cap. I removed the end with the wires which gave good access to measure and trial fit the parts. Place the shaft end in the vice and twist the end cap (wire end - I used the holes rather than grip the outside face), this will break the adhesive. The case can now be pulled apart in hindsight gripping the shaft end of the case and pushing hard on the shaft would probably have worked but I used a hammer (arrgh)

You should now be able to clamp the shaft in the vice and twist the magnetic section off the shaft, if you're lucky the bearing will be pushed off by the thread

Like I said earlier I stripped the thread by pushing the shaft out. A 10/24 UNC gave the correct depth of metal to cut a new thread, but perhaps more importantly a tray full of 10/24 long bolts gave an excellent starting point for my shaft.

Cut the head off the bolt, screw into the magnetic section (from the magnet side) and you have a new shaft. Measure and machine either end accordingly.

Assemble your parts when done and don't forget to use loctite or equivalent, good luck. Any queries please post to my forum

Bob

More piccies:-