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Thread: Repairing a Manfrotto 410/Bogen 3275 tripod head

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    Dec 2018
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    Guelph, Ontario, Canada
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    Repairing a Manfrotto 410/Bogen 3275 tripod head

    The Manfrotto 410/Bogen 3275 is still a good choice for a sturdy and not terribly expensive head for times when you need precise movements and a ball head won't do. I use it on a Feisol 3441T tripod. This combination is plenty sturdy for a camera in the 6 lb range (like my Wista 45VX). Unfortunately, these heads have some parts that are "consumable". After a lot of use (or abuse), it can become extremely difficult to turn the knobs because a key gear has worn out, and sometimes sections can come loose. Fortunately, this is a highly repairable head.

    There have been other threads years ago about these heads, but I couldn't find one that walked me through the repair process with pictures. So for posterity, I'm pleased to share this summary. A few pictures are at bottom. All of the pictures are available here on a Google Drive folder:
    https://drive.google.com/drive/folde...au?usp=sharing

    To be clear, the repairs I'm describing are limited to the following problems: stiff knobs, stiff movements when using the "large movement" mechanism, and loose sections. I did not remove the knobs or work on the mechanism that holds the plate. Those are both more complicated repairs that you may want to leave to a professional.

    Tools you need are basic: a 4mm Allen key; a razor knife; paint thinner or Varsol and a toothbrush; some kind of goo remover; rubber gloves; paper towels; and some appropriate grease. I used a good quality marine grease I had lying around from a previous tripod repair.

    This is a geared, three-way head. You may need to repair just one section, or all three. The procedure is almost identical for each section; only the bottom section is a bit different.

    (1) You need to gain access to the Allen head screw that hold each section together. These screws are under the round plastic disks that have the Manfrotto name and degree markings. These disks are made of a thin, tough plastic material that is held on with thin, foam-cored double-sided tape. You'll probably want to reinstall them when you're done, so remove them carefully by slipping the tip of a razor knife underneath and gently cutting through the foam core of the tape. Lift it off, and then use your goo remover to clean off the tape that was left on the sticker and on the tripod where the sticker was attached.

    (2) Next, you need to undo the screw that holds the two pieces of each section together. The screw might be quite tight. I didn't see any signs of Loctite or other substances holding them down on mine, but they were very firm. You will wreck the screw head if you use the wrong sized Allen key so make sure it's 4mm and not an Imperial one that "nearly" fits. On a head where the parts are loose, it might be easy to undo them (because they're already loose). If they're tight, firm but steady pressure will do the trick. Unscrew the screw completely. It's holding down a small round plate onto which the sticker was attached.

    Removing the screw will allow you to separate the two components of that section. On one or the other of the parts, you'll see a small thin plastic gasket (ring). It might fall off on its own, or it might be stuck on with a bit of grease. If you started with one of the two top sections, the plastic ring will have a notch. The ring on the bottom section (which attaches to the tripod) has no notch. Take note of how the notch in the ring fits into a short post in the part of the section that is still attached to the head. In my pictures, you'll see several photos where the wrong ring was being used; someone had previously tried to repair the head and didn't notice the notch and post. There's one picture that shows the ring properly installed over a post.

    Wipe the ring clean, and clean off old grease on the "teeth" of the section that doesn't have the knob. A bit of Varsol or paint thinner on the toothbrush will do the trick. Make sure to wipe the parts clean and dry.

    (3) Now you have to remove what I'll call the "thimble gear" from the section that came off the head (the part with the knob). Notice how it has what seems to be an inner part made out of aluminum and is smooth on the visible inside surface. The thimble gear has teeth at one end that mate with the teeth on the part to which it was attached with the bolt. On the toothed-side of the thimble gear, while it's still inside the main part, make a tiny scratch in the aluminum to indicate where it was in case you want to put it back in exactly the same spot. Take a picture so you'll remember how it lines up.

    To remove the thimble gear, operate the large movements mechanism. With the teeth of the thimble gear facing up, turn the mechanism until the thimble gear drops out; you might need to press gently to make it come out. As you can see, the part that dropped out will look like a large thimble with long ridged gear teeth on the outside and teeth on the end.

    If you look on the now exposed inside of the part that has the knob, you'll see a brass worm gear in a cut-out section. If you turn the fine movements knob, the worm gear spins. If you twist the large movements mechanism, you'll see that the shaft of the worm gear will twist into the cavity containing the shaft. This is how the gears are disengaged in use. When you operated the large movements mechanism, you twisted the worm gear away from the thimble gear, allowing it to come loose.

    Both the thimble and the worm gear will probably be gunked up with old grease. Clean them with paint thinner or Varsol and the toothbrush. You can dunk the thimble gear into the solvent, but easy does it on the worm gear side. You don't want to get solvent into the mechanism that has the knob. Hold the part in such a way that the solvent will drip down and away from the knob as you're working. Dry both parts, being careful not to leave behind bits of cloth or paper towel.

    Once you've cleaned and dried the thimble gear, examine the teeth. If you found it hard to turn the knob, or if it varied between easy and hard as you turned it, then you will probably see that the teeth on the thimble gear have been damaged. If you're working on one of the two upper sections, the damage may be limited to the 1/3rd of the thimble gear that engages the worm gear. On the bottom section the damage could go all the way around. If the damage is extreme, you should probably replace the part (Manfrotto sells still sells them). However, on the top two sections, the worm gear only ever touches one section (that 1/3rd zone). If the remaining two-thirds of the gear have good teeth, you can re-install the gear with the damaged teeth opposite the worm gear. That's what I did. It's not perfect, but it's vastly better than it was. Note that the thimble gears are interchangeable. I actually swapped out the bottom one, which was in better shape, with the top one.

    (4) Use a good quality grease and lubricate the teeth of the worm gear, the face of the thimble, and the top and bottom lip of the thimble. Easy does it with the grease -- just use enough to lubricate the parts that will move against each other.

    (5) The only tricky step in reassembly is you have to operate the large movements mechanism to get the thimble gear back into the housing. Practice twisting it first to see how far you have to turn to get the worm gear completely out of the way. It will take some effort. While still operating the large movements mechanism to get the worm gear out of the way, gently insert the thimble with any damaged teeth opposite to the worm gear. It should just slip into place if you're doing it right. Gently ease back on the large movements mechanism until the gears mesh. If the teeth are undamaged and you want to put it back together in the original position, take note of the mark you made before disassembly. If it's a used head you most probably will want to install fresh gear teeth against the worm gear side.

    Next, you have to put the thin plastic gasket ring back in position between the teeth on the top of the thimble gear, and the teeth on the tripod head side. For the upper two sections, make sure the notch in the plastic ring goes over the post on the head side. If you put a bit of grease on those teeth, the ring will stay in place on its own. You can see the gasket properly installed in one of the pictures.

    You can seat the two pieces of the bottom section together at any point (because the head can rotate 360 degrees). However, the top two sections have limited ranges of movement, so make sure to seat them so that the post on the head side fits into the space that has been carved out to take the post on the part that has the knob. You can see this in the pictures.

    While holding the two parts together, drop the round cover plate into position, insert the bolt and tighten it down finger tight. That component of the head should still move easily when you operate the large movements mechanism. There should be no play. I found it easiest to test at each stage by putting the head back on the tripod. On my copy of the head, I could tighten the bolts down firmly without affecting the ability of the section to move freely, but on one section the same tightness made it stiff. I adjusted each bolt until the sections just moved freely, and held them in place with a drop of Loctite.

    Once you're sure that everything is in order, you can stick the cover labels back on with very thin two-sided, foam cored tape.

    Rob de Loe
    Guelph, ON
    Canada
    Attached Thumbnails Attached Thumbnails 01 Bottom section with label attached.jpg   02 Plastic covers after cleaning.jpg   03 Bottom section with label removed and bolt partially withdrawn.jpg   04 Bottom section prior to separation of the two parts -- note smooth interior of thimble gear p.jpg  

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