I'll make some suggestions regarding your questions separately....
texasdan wrote:
I have a two part question:
1 - I recently purchased a used Manfrotto BeFree tripod but I need to convert the ball clamp to an Acra Swiss clamp. I have looked on the web but found the adapters very confusing and I am not sure which would work....
Three possibilities occur to me... First is to use an adapter, the second is to modify the ball head, third is to simply replace the ballhead with one that's Arca-compatible.
The BeFree tripods I looked at used a Manfrotto 494 ballhead. The version of that head that doesn't have a quick release (QR) can easily be used with a 1/4"x20tpi threaded Arca-Swiss platform (or one that's 3/8" threaded, using a 3/8 to 1/4" bushing, which is typically included with A-S platforms). I'm in the process of adapting an old Bogen/Manfrotto head that way myself, but this only works with heads that have the standard 1/4" screw mount... i.e., NOT the ones with one of several different Manfrotto's proprietary QRs.
I don't have the QR version of that head, which appears to use the newer type of Manfrotto 200PL plates:
https://www.bhphotovideo.com/c/product/1375463-REG/manfrotto_200pl_pro_200pl_plate_aluminium_rc2.html/?ap=y&smp=y&lsft=BI%3A514&gclid=Cj0KCQjwiILsBRCGARIsAHKQWLMaX_z9wJiU8Z_Zo1Y-30sjSyPtxJmKO0o56ZJx4jPZ0EzSZX8efeQaAsYwEALw_wcB. That type of plate is compatible with Arca platforms. BUT other Arca plates are NOT fully compatible with the platform on this head. Due to the way the plate is clamped into the platform, only plates of the same length can be used. AFAIK, there is NOT an adapter available for this platform, to allow other Arca plates to be used on it.
I don't have a 494 QR head to say whether it's possible to modify or not. I think most of them are pretty easily converted. Look at the QR platform underneath the QR plate and see if the platform appears to screw onto the pedestal. If so, it might be possible to unscrew and remove the entire platform and replace it with one that's Arca-compatible. I did that with an older Manfrotto ball head some years ago and it works fine. Turned out that the pedestal used the same 3/8" thread mount as Kirk platform I bought to use on it. (I screwed it on with some red Locktite and it's never come loose.) Today most recent Manfrotto ball heads instead use an Allen headed screw from above to attach the QR platform to the stem of the ball head. Those are even easier to modify, and cheap platforms are available from China. If using really heavy gear, you might want a more expensive replacement platform from Pro Media or Kirk or RRS, etc. See below for a video how to replace the platform on many of the more recent Manfrotto ball heads, that use this sort of attachment method.
Replacing ball head platform videos:
https://www.youtube.com/watch?v=WT9FNoP7zs0https://www.youtube.com/watch?v=I3aR8LNRj5UThe platform I recently ordered from China to fit the old Bogen/Manfrotto head (not QR) also would work if there's just a 3/8" thread on the stem of the ball head. This generic type of platform is pretty inexpensive!
https://www.ebay.com/itm/QR-Plate-Clamp-for-Arca-Swiss-Type-Quick-Release-Plate-Universal-Clamp-Seat-New/333296603564?ssPageName=STRK%3AMEBIDX%3AIT&var=542311250938&_trksid=p2057872.m2749.l2649 I will drill and tap the head to be able to add a couple "locking" screws to prevent this adapter from loosening.
Finally, I'm pretty sure you could simply replace the entire ballhead with one that's already got an Arca-compatible platform, thought this would likely be a more costly solution. I would bet the head on the BeFree tripod simply unscrews and that it uses a standard 3/8" mounting, as do most tripods and heads. There may be some countersunk set screws underneath the head mounting platform on the tripods center column. Turn it upside down to look for those. (There were three set screws on the old Bogen/Manfrotto I just bought for $10 at a local second hand store.) Loosen those set screws before trying to unscrew the head itself to remove it from the tripod. (Those screws are there to prevent the head unscrewing accidentally.... to lock it in place.) After that and assuming you find a standard 3/8" mounting bolt on top of the tripod center column, next you'd just need to look for head that has approx. the same dimensions and features you wan, including an Arca-compatible QR platform.
As to your second question....
texasdan wrote:
2 - I have the same problem with a Manfrotto 393 gimbal with a 357PLV Quick Release Plate. I need to use an Acura Swiss plate.
I see less options here. That head uses a special QR platform and plate, similar to but not cross-compatible with Arca-style plates. There appears to be no way to fit an adapter to that and none available. Unless you use the trick of attaching an Arca-platform to the QR plate Manfrotto provided (which makes for another joint that can come loose) I think on that gimbal head you will need to replace the platform completely, if it's possible. Look under the QR plate and also swing the platform upside down to see how the existing platform attaches to the u-shaped legs of the gimbal and if there are any locking screws. I don't have a 383 gimbal head to check.
Assuming the existing platform can be removed and uses a standard type of threaded mount, because of the way that gimbal is designed, I don't think you'll be able to use a QR platform like the one I linked above, that has a knob to tighten the clamp. The arm of the gimbal would interfere with operating the knob on the platform.
I think you'll need an Arca-compatible platform that has a lever type clamp, such as this:
https://www.ebay.com/itm/Plate-Tripod-Camera-Adjustable-Durable-Quick-Release-Clamp-For-Arca-Swiss/293215440858?hash=item4445008fda:g:WAwAAOSwu2ldcXylNotice that lever type platform also has a threaded knob, but it's a smaller diameter to clearance anything the platform might be mounted on. If a platform like this can be fitted to the swing arm of the 393, I'd prefer a somewhat longer platform, if possible.
EDIT: I just found this made specifically to convert the Manfrotto gimbal for Arca-compatibility!
http://www.hejnarphotostore.com/product-p/m393f64ab.htm and
https://www.ebay.com/itm/Manfrotto-393-conversion-4-arca-swiss-kirk-markins-wimberley-acratech-/231829975377$90-$100 may seem a bit pricey, but Hejnar Photo stuff is very good quality (and it's usually not as expensive as RRS or Kirk or some others). I'm using one of their tripod mounting feet on one of my big telephoto lenses and it's rock solid.