So, I made this simple gear puller at the TechShop.ws in Menlo Park, California.
Step 1: Materials and Tools
2 inches of: 1.5 inch x 0.06 inch Hot Rolled Mild Steel Square Tube A513 [Online metals.com $0.64]
1.25 x 0.25 inch bolt (20 threads per inch)
TOOLS (available at TechShop.ws):
3/8 inch diameter drill bit
7/32 inch diameter drill bit
1/4 - 20 thread tap
tapping fluid (light oil)
Bridgeport mill and 3/8 mill end
(or band saw)
Step 2: Make Gear Puller
2. Tap one side of hole with 1/4 -20 tap:
a. insert tap into tap handle
b. coat tap with tap fluid (oil)
c. twist tap into hole perpendicular to surface one revolution.
d. untwist by 1/4 revolution
e. repeat last two steps until tap is 3/4 inch into hole
f. unscrew and remove tap from hole
3. Drill other hole larger with 3/8 drill bit.
4. Cut 3/8 inch wide slot from the 3/8 inch to end of square tube
a. Take Milling safety and basic use class (Mill is very dangerous)
b. Hold square tube in vise on Bridgeport mill
c. Secure 3/8 mill end into mill
d. Set RPM to about 500
e. raise square tube until the 3/8 hole overlaps mill end by 1/2 inch
f. Move (spinning & cutting) mill end through the end of tube (actually by moving vise and tube)
Step 3: Use Gear Puller
1. Slide gear into gear puller (square tube) with shaft sliding through slot.
2. Insert and tighten bolt into threaded hole of gear puller to contact end of shaft.
3. Tighten bolt through center hole of gear pushing shaft out.
4. Loosen bolt and free gear