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Midwest RDH Handpiece 

Repair Procedure 

 

 
The Midwest RDH handpiece is fairly common and is used by hygienists to clean teeth. 
The most common problems for this handpiece include a bad prophy head or a dirty 
motor.  Both of these problems can be easily solved.  As always, try to determine the 
problem before disassembling the nosecone. 
 
Some signs to look for are:   

 

The Motor is locked up: 

o

 

Try removing the prophy head and running the motor.  If the motor now 
runs freely without the head, simply replace the prophy head (Part# SO-
720445).  If not, disassemble and overhaul. 

 

There is little or no torque when the motor is running: 

o

 

You may have a cracked drive gear at the top of the nose section, or you 
may have a dirty motor in need of overhaul.   

 

The nose section spins when the motor is running 

o

 

This is a sign of a faulty prophy head, simply replace the head. 

  The repair procedures for each of these problems is addressed below 

 

STEP 1 

To remove the nose portion from the motor portion, secure the nose 
assembly approximately ¾ up the shaft.  Use about a ¾” collet to hold the 
nose.  Then wrap the motor housing with a strip of rubber and gently wiggle 
the housing while simultaneously pulling up.  This will allow the two pieces 
to work apart.  

 
 

 

STEP 2 

Remove the two 
pieces and set 
them on your 
work surface.  

You can now see the retaining clip that was holding the two pieces together.  Try to be 
careful with this clip as it is hard to replace. 

Summary of Contents for RDH

Page 1: ...ning o You may have a cracked drive gear at the top of the nose section or you may have a dirty motor in need of overhaul The nose section spins when the motor is running o This is a sign of a faulty...

Page 2: ...ke time to note that the motor canister sits correctly in the base piece by aligning posts The two male posts in the base piece line up with the two female holes in the canister At left you can see th...

Page 3: ...liers into the two holes in the top plate of the canister far left picture This plate is standard thread so turn it counterclockwise to unscrew Once the top plate is loose lift it off the motor and re...

Page 4: ...gnment pin in the plate up with the top hole in the inside of the canister Both the pin and the appropriate hole are at the top of the picture STEP 9 Now start to thread the motor canister top plate i...

Page 5: ...p it out using a small thin punch Remove the gear and replace it with a 60219 gear and 60219A retaining pin The above picture shows the disassembled nose section The top gear is replaceable but the ma...

Page 6: ...e RDH with a strip of Gum Rubber 00032 Once tight slowly jiggle the nose section while also pulling up This should release the nose section from the main RDH Body STEP 2 Insert your 00014 MW Nosecone...

Page 7: ...p washer has been removed you can slide the 60102 spindle bearing up and off of the chuck as well If the chuck is broken simply tap out the small 60219A pin holding the chuck and drive fork together 1...

Page 8: ...is thin with an internal bevel while the top edge is thicker with a flat surface Insert the main spindle assembly into the thinner beveled edge of the bearing spacer Next while holding the assembly u...

Page 9: ...C clip slips into the upper edge of the main RDH body and the Zip Tie has been pushed up to the main knurled edge of the nose section Then simply cut the Zip Tie loose with an exacto knife and firmly...

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