Service Pointers

Service Methods and Tips

MAY/JUN 2003
Volume 46/Issue 3

IN THIS ISSUE
Project Articles
• Wall-Hung Curio Cabinet
• Mobile Potting Table
• Pencil and Stamp Holder

DEPARTMENTS
• Ask Smitty
• Owner’s Gallery
• Letters from Owners

Academy Notes
Furniture Joinery

Service Pointers
MARK V Speed Change Mechanism

Safety Tips
Safety Do's and Don'ts

What's New
Shopsmith and Lowe's Team Up

EDUCATION
• Find A Shopsmith Woodworking Academy Near You
• National Woodworking Academy in Dayton, OH

ONLINE CATALOGS
• Online Accessory Catalog
• Request Printed Accessory Catalog
• Online Replacement Parts Catalog

MARK V INFORMATION
• Find A Shopsmith
MARK V Demo Near You
• Request MARK V Information Package

LINKS
• Links Worth Visiting
• Free Woodworking Tips

FEEDBACK
Contacting Shopsmith

Service Pointers
MARK V Service Pointers
- Speed Change Mechanism
Printer friendly PDF copy of article

The ease of changing speeds is one of the most desirable features of the Shopsmith MARK V. By adjusting the motor speed between 700 and 5,20 rpm, you can perform a multitude of operations, including sawing, molding, sanding, lathe turning, drilling, shaping and more.

The Shopsmith speed change mechanism relies on sliding sheaves that increase or decrease your MARK V's speed by increasing or decreasing the diameters of driving or driven pulleys. This unique pulley system allows an infinite variation in speeds and enables you to select the exact sped for any given operation.

Such precision parts require regular oiling to ensure the smoothest possible movement - a few drops of lightweight machine oil applied every ten hours of actual running time is recommended.

The speed control mechanism is located inside the MARK V's headstock. Its accuracy depends on regular maintenance. However, sometimes, it demands a little more. Here's a handy, quick-reference trouble-shooting chart for those times.

Problem	Possible Cause(s)	Remedy
Won't change from high to low speeds	Retaining Loop may be disconnected Control sheave is sticking	Remove nameplate from back side of headstock and press leaf spring in on the quadrant, then re-hook the loop. Remove the nameplate from the back side of the headstock. Reach in and try to slide the control sheave. Oil the shaft and work the oil in.
Spindle stops turning when speed dial is turned from high to low	Floating sheave is stuck	Remove belt cover and oil motor shaft. Move sheave by hand. Belt may have slipped between control and Poly-V sheaves.
Speed dial “creeps” during operation	The spring (504228) may not have sufficient tension	Remove the control handle. Remove the screw that holds the spring and gently bend the flat spring to create added tension.
Very hard to turn speed dial when moving from high to low speed	Sticking sheaves. Keys on shafts may be bent.	Oil both control (504781) and floating(504208) sheaves. If oiling doesn't help, file of any burs or replace the bent key(s).
Speed changes although dial remains at same setting when changing speeds	Bad control handle	Gear in back may be stripped. Remove control handle and check. If so, replace.
Speed dial turns...but speed remains the same	Worn quadrant Loop disengaged	Check teeth on quadrant. May be stripped. Remove nameplate from back side of headstock and check. If stripped, replace. Remove nameplate from back side of headstock and rehook loop onto quadrant.