Introduction: Repair the Leg Locks on Your 728B Manfrotto Tripod W/ 3D Printed Parts
Recently I was given a Manfrotto 728B tripod that was in pretty rough shape. It seems cam-acting leg locks on this particular model are prone to cracking. If you look close you can see the plastic is very thin at certain areas and with the cam lock putting a high bit of stress on the joint its no wonder why all three locks were cracked. Well not to let a potentially good piece of camera equipment go to waste I searched the internet for the replacement hardware.....The best I could find was $15 per set. Now multiply that by 9 sets and the notion that they wouldn't last very long leads me to this instructable....I got to thinking I could make better replacements myself.
With a little reverse engineering, some beefing up of the side walls, and a short run on my friend's 3D printer....Voila! I got a new and improved tripod with a little personal touch added to it.
You can find my 3D stl files on Thingiverse.com under the heading "Tripod Cam-Lock Repair" or under my username of "frubino".
Special Note: If you like this Instructable, please cast a vote for me on the UP 3D Printer contest. I personally would love to have a printer of my own and spare the pressure I put on my friend who has one and has been patient with my needs.
THanks for your support Joe.
Step 1: Tools & Material
Tools & Materials Needed:
2. Drift/punch/old nail (1/8" or 3mm diameter)
3. 3D Printed Replacement collars
4. A small blade
Step 2: Disassembly
A. Holding the collar securely in your hand, use a hammer and punch to gently knock out the brass pin which secure the cam lever to the original collar.
B. When the cam lever is removed, a small piece of rectangular plastic will most likely fall off. If it doesn't fall out gently pry it out with a knife blade. This little piece of plastic sandwiched between the cam lever and the inner aluminum leg is what puts pressure on the leg when you lock the lever. Save this piece of plastic, even if its broken in half.
C. Knock out the old collar gently with a hammer.
D. Slide the inner leg out.
E. Slide off the inner sleeve from the upper tube.
When you remove the pin you will be left with 7 parts for every joint:
- original (broken) collar
- cam lever
- brass pin
- pressure pad
- Inner sleeve
- flared lower tube
- notched upper tube
Step 3: Re-assembly (Sleeve Install)
Slide on the inner sleeve onto the lower tube. Make sure to align the open end of the notch in the inner sleeve so that it faces the flared end of the lower tube.
Step 4: Re-assembly (Lower Leg Meets Upper Leg)
Slide the lower tube into the upper tube. Make sure the notches of both the inner sleeve and the upper tube line up. Press the inner sleeve completely into the upper tube.
Step 5: Re-assembly (New Collar Gets Installed)
Press the new 3D printed collar over the upper tube. Make sure to orient the collar so that completely presses into the upper tube and the notch on the collar lines up with the upper tube notch.
Step 6: Re-assembly (Press on Cam Lever)
Drop the pressure plate into the rectangular hole. Even if the plate is broken, assemble it in the rectangular hole of the collar with the little number molded on the back facing away from the cam lever.
Line up the cam lever with the rectangular hole of the collar and push in the brass pin with the lever in the open position.
Repeat the following 5 steps for all the broken joints.