I just bought a used Don which was advertised as having a faulty switch, the main problem being the switch was hard to push and was always sticking, it was very heavy to use and also felt very rough in its operation,
After searching the net for about an hour it seems that everyone thinks its the spring thats at fault, also the little nylon bung on the end of the spring has come in to question, granted the spring is quite heavy and should be lighter... but im quite sure that aint the problem for most people.... check this out... it may be your problem if you own a Don,
If you look at the picture below you will see a small channel on the switch shaft, there are two in total and are set adjacent to each other, .. when the switch is unlocked there is a small ball bearing that drops into that channel, when pressing the switch the ball bearing slides along that channel.... there lies part of the problem.
When you lock the switch you are technically forcing the bearing back out of that channel,,, the problem is....... the ball bearing is steel, the switch is brass... you cannot run steel on brass, the steel will wear and damage the brass every time,... the reason the switch is rough and tight in operation is because the ball bearing creates a raggy jagged burr on the brass where the bearing enters and exits the channel....... i tried to photograph it but my camera couldnt pick it up.
All you need to do is use some wet and dry or a small model makers metal file and dress up the edges of that channel.. you also need to lightly run wet and dry around the shaft .. the above pic shows the repared channel.
I have sat for a while doing mine and the switch is smooth as hell...... below are more pics of a switch that i stole off the net just to show what it looks like inside..... good luck coz its a pain ..... to put back together....lol... ignore the red circle .. that was allready on the pic for some reason....
whoops .. almost forgot, if you want a lighter spring you can use the springs out of one of those pens that have four different colours in them, a regular spring loaded clicky pen has the same tension spring as the stock one in the Don.
After searching the net for about an hour it seems that everyone thinks its the spring thats at fault, also the little nylon bung on the end of the spring has come in to question, granted the spring is quite heavy and should be lighter... but im quite sure that aint the problem for most people.... check this out... it may be your problem if you own a Don,
If you look at the picture below you will see a small channel on the switch shaft, there are two in total and are set adjacent to each other, .. when the switch is unlocked there is a small ball bearing that drops into that channel, when pressing the switch the ball bearing slides along that channel.... there lies part of the problem.
When you lock the switch you are technically forcing the bearing back out of that channel,,, the problem is....... the ball bearing is steel, the switch is brass... you cannot run steel on brass, the steel will wear and damage the brass every time,... the reason the switch is rough and tight in operation is because the ball bearing creates a raggy jagged burr on the brass where the bearing enters and exits the channel....... i tried to photograph it but my camera couldnt pick it up.
All you need to do is use some wet and dry or a small model makers metal file and dress up the edges of that channel.. you also need to lightly run wet and dry around the shaft .. the above pic shows the repared channel.
I have sat for a while doing mine and the switch is smooth as hell...... below are more pics of a switch that i stole off the net just to show what it looks like inside..... good luck coz its a pain ..... to put back together....lol... ignore the red circle .. that was allready on the pic for some reason....
whoops .. almost forgot, if you want a lighter spring you can use the springs out of one of those pens that have four different colours in them, a regular spring loaded clicky pen has the same tension spring as the stock one in the Don.
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