This is a simple yet really affective way to service/ Repair your Dremel 225 Flex Shaft Tool.
I am sure there are many who have worn out a few of these 225 flex shafts.
I am going to help you solve all these problems that you may have come across,
1) You detect unnecessary noise
2) You find the tool overheating
3) You are unable to attach or detach accessories as the shaft lock button wont work.
4) You are wondering where all the grease has disappeared.
5) Here is the common one you find that when you hold the hand piece in a pencil grip the shaft lock button and logo does not face you and the two screws is all you see.
Since there are different situations involved i will not be using steps in this instructable.
MAKE SURE YOUR TOOL IS SWITCHED OFF , UNPLUGGED AND ON THE LOWEST SPEED SETTING BEFORE YOU ATTEMPT ANYTHING.
The only tools you will need are a Philips screwdriver, any blunt flat object and appropriate grease.
Lay the Tool with the shaft flat on a large table to begin disassembly do not hang the tool, or the shaft will keep slipping out.
First Fix the shaft to the tool and then unscrew the Housing Cap, Collet Nut and collet from the flex shaft (Except Situation 3).
Slowly easy out the spring end of the hand piece by gently pulling on the spring, easing out one coil at a time. DO NOT use excessive force or stretch the spring too much.
Here you might need magnification and good lighting for this step and need to use a fine blunt blade or screw driver tip ( do not use a sharp knife or any sharp object or you can damage the rubber sleeving or threads for the housing cap)
If you look at the hand piece under magnification you will notice a real fine metal ring on both ends of the hand piece.
Mark the rings and note their position so that you don't mix them up as they are different . The one on the front has a smaller collar the one at the rear has a larger collar. Both rings are fitted with the collars facing away from the tool (collar faces housing cap and the other towards the spring)
Once you pry the ring just enough, you can ease it out gently then go ahead and do the next ring. Make a tiny marking or a bit of tape around the rubber shaft so you can easily know how much is inserted back while reassembly. This will help those trying to correct Make a tiny marking or use a bit of tape around the rubber sleeving so you can easily make corrections if needed. (Symptom no 5) above easily.
You may be wondering why I have not mentioned anything regarding removing the two screws first, the reason is that the screws hold down the hand piece which is in two halves and aid in removing the two rings.
Now its time to remove the screws and the unit will open.
You will find inside a long shaft with two bearings attached a spring clip and lock button along with a white shaft guide.
Here is what to check
This is where you will find the old grease, which you can wipe off with a rag. this should solve you problem of overheating in the hand piece. (Symptom no 2) above.
Check the shaft with the two bearings once cleaned out if you see any deep circular marks next to the tiny hole which your shaft lock button engages, it is a sign that the lock spring is weak or out of shape and is causing the tiny portion on the lock to rub against the shaft. This will cause the hand piece to over heat (solution to symptom no 2) and in some cases the button is worn down and unable to engage the shaft lock (solution to symptom no 3)
If the spring is weak it can be replaced or have one made or you can even re temper it.
If you still want you can do away with the spring and button and just use a broken / worn drill bit to engage through the tiny hole and still be able to change out burs/brushes etc. (solution to symptom no 3)
The unnecessary noise that some may find (Symptom no 1) could be caused due to many reasons
Incorrect Collet used or not balanced
Worn or dry bearings due to over greasing or not greasing at all.
Broken or weak lock spring
For those of you who notice your hand piece originally came fitted with the lock and logo facing upside down when you hold it using a pencil grip like mine did , now is the time to correct this during re assembly.
Make sure the rubber sleeving that goes into the hand piece does not rub against the round white shaft guide or this will create friction causing overheating and vibration along with a funny sound.
While trying to correct (Symptom no 5) raise the tool slightly check that you have the proper grip you want ( shaft lock and logo facing up) and then being re assembly.
Handy Tip I screwed on the Housing cap while holding the hand piece to check everything was ok before fitting back the two rings screws and spring.
DO NOT PUT ANY GREASE INSIDE THE HAND PIECE.
DO NOT USE OIL OR WD40
Once you have finished re assembly you can lightly grease the shaft drive. The part number for Dremel grease is 990952. It is recommended to lightly grease after every 10 hours of use.
Now its time to give it a go hang up the tool and run the flex shaft with and without the collet nut and collet at the slowest speed and check for any vibration or noise . If all is ok gradually increase the speed and run for two minutes once full speed is attained.
REMEMBER TO USE PROTECTION BEFORE RUNNING THE TOOL WITH ANY ACCESSORY ATTACHED.
NEVER TRY TO STOP THE HAND PIECE BY PRESSING THE LOCK BUTTON.
DO NOT BE IN A HURRY THE FIRST TIME YOU TRY THIS.
I succeeded on the 3rd or 4th attempt and I am glad as this helped me find a solution to the 5 most common problems faced with the 225.
If you read and follow the steps above you should be able to resurrect any busted flex shafts you have lying around. The entire process should take around 20 to 30 minutes.
I hope this helps other Dremel users I will appreciate any kind of feedback and questions or simply just letting me know if this helped you to fix your 225 flex shaft.
If you like this take a look at my other Dremel DIY's and follow for future tutorials.