NikonGear'23

Gear Talk => Other => Topic started by: David Paterson on February 01, 2018, 18:54:22

Title: ArcaSwiss ballhead won't lock
Post by: David Paterson on February 01, 2018, 18:54:22
I have a rather old but much used and much loved ArcaSwiss ballhead on which the rotating base - quite suddenly - refuses to lock, no matter what I try. The whole upper part of the unit, plus whatever camera is in use, is free to rotate. Does anyone have experience of this problem and, more importantly, was there a fix?

I'm rather dexterity-challenged these days so a complex repair will probably be too difficult, but any and all advice welcome.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Bjørn Rørslett on February 01, 2018, 21:50:53
I'm sure there is a fix, but am not familiar with that head so cannot produce any useful answers. A competent mechanic or repairman ought to be able to disassemble the head and find the root cause, though.
Title: Re: ArcaSwiss ballhead won't lock
Post by: richardHaw on February 02, 2018, 06:23:55
i have opened several. some uses a rubber or silicone-type stud inside while others use metal.
how it operates is basically the knob squeezing the rubber or metal part (with rubber pads for friction) and that is what's holding the ball. :o :o :o

possibilities:

I also have that super hard silicone grease for repairing tripods. you can't just use any type of grease for this. some people use automotive lithium grease. while that was acceptable before it's not advisable now that there are better options available. the silicone one that I use repels water very well. I used to shoot at the sea every weekend and it does the job. however, I have to relube it often because of the very fine sand particles that can make the tripods gritty.

one important part is graphite powder. I ran out of it and they aren't cheap here in Japan. They are great for lubricating the ball and the helicoid for the S and Contax cameras because they're dry, so no damping/resistance.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 02, 2018, 10:23:49
Richard, Excellent description of the damped 'silicone' ball head damping and locking mechanism but Davids problem is I think, specifically the rotating base.

Is far as I know the base doesn't benefit from the damping of the ball.  The base is usually a separate simple friction lock. My Benbo tripod legs have plastic pads to lock the extension, which age harden and split with repeated clamping and releasing, making them useless.  My best guess is there will most likely be a nylon or Delrin friction pad which locks the base rotation and that the pad has split apart.

Shame about the reamed screw, that's no big problem, it will either extract or drill out easily and be replaceable. Probably three new screws and a new nylon/Delrin (or possibly bronze?) friction pad which will probably be simple and easy to make and will effect a lifetime repair.
Title: Re: ArcaSwiss ballhead won't lock
Post by: David Paterson on February 02, 2018, 11:57:40
Thanks for these very helpful posts. However I'm having a problem with PMs at the moment - my messages are being blocked for some reason. 

It does sound as if the repair would be beyond my own capabilities.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 02, 2018, 12:38:26
OK David, I have sent you PM...

Basically if you can't deal with it and you have no local solution send it to me and I will do my best to sort it.

If you can PM me your eMail? Perhaps you can send but not receive?

Perhaps Admin can Unblock your PM's?
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 02, 2018, 18:00:37
PM mystery solved...

My preferences were set to receive PM's form Admin only for some reason, I can't remember changing that.

Anyway I have now set to receive PM's from everyone.


Edited, spelling, or rather, auto correct!
Title: Re: ArcaSwiss ballhead won't lock
Post by: richardHaw on February 03, 2018, 12:51:40
I see, I got confused  :o :o :o

not sure if the Arca Swiss is similar to the ones I have opened but this sounds like something got loose, a nut perhaps and it jammed ::)
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 03, 2018, 15:45:20
No Problem!

It's on it's way to me this weekend, may have it Monday.  Will document the process and see what  the trouble is.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 05, 2018, 13:19:48
Mended!  ;D ;D ;D

Will explain later, have to dash...
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 05, 2018, 16:56:49
OK, caught up, sort of.

This rather took me by surprise, my suspicion that it was a simple fault was right, but not being familiar with this ball head it threw me for a moment.

The faults were two fold, firstly the body of the retainer sleeve for the rotation lock was loose, it should have been tight.  Secondly the rotation locking knob had been unscrewed over-strongly which had unscrewed the body of the retainer sleeve from the main ball head body.   I wasn't sure how it worked at first, not wishing to damage anything I approached it gingerly.  Eventually I gripped the retainer body in a pair of pliers and applied some force, Yea! the knob came loose in it's retainer.  Job done!  Almost.

I extracted the reamed screw, identified the thread as M3 x 0.5mm pitch.  I rummaged through my boxes of screws and found some stainless steel Torx screws which I had salvaged from one of my Mac computers.  It was my liquid cooled G5 Tower, these screws secured the logic board to it's mountings and are really nice quality.  However, they were cheese head, not countersunk.  Off out to the lathe, eventually found some aluminium bar, drilled and threaded it M3 and screwed one of the screws I had found into the end of the bar, tightened it then cut a countersink at 45º so the screw fitted perfectly.  Then I did two more, these replaced the other two original screws.  They need a TX8 driver.

The three other screws accessible through the hole in the rotating base must be left well alone...  They are special screws which are designed to tighten but not unscrew.  They have a clever 'one way' clutch design which allows the screws to be driven in but not unscrewed without either special tools or destroying them by grinding or cutting the heads off.

Some pix...

The rotation lock screw and housing, in the unlocked position, as I found it, unscrewed tightly and jammed:

(https://farm5.staticflickr.com/4674/28318381359_fb11a33b1c_b.jpg)

The rotation lock screw and housing, in the locked position, achieved by screwing the knob in:

(https://farm5.staticflickr.com/4649/40066452672_fa9a0e4e8d_b.jpg)

The lathe, set up with aluminium bar in the chuck:

(https://farm5.staticflickr.com/4740/26224920718_3ca75b3713_b.jpg)

Close up of the screw:

(https://farm5.staticflickr.com/4698/39200227895_84121ec13d_b.jpg)

And from the back:

(https://farm5.staticflickr.com/4702/39200228705_f37bbcb3df_b.jpg)

These pix were taken with my D3300 and my rough, workshop 18-105 VR lens.

I propose to apply some thread lock to the rotation lock screw housing threads to prevent the housing coming loose again in the future.  I may apply a tiny amount to one of the rotation plate screws too.  One, the one which reamed had had thread lock applied.  If anybody thinks it would be better not to apply Locktite please tell me, these screws are small and could ream again with Locktite applied.

Your thoughts David?
Title: Re: ArcaSwiss ballhead won't lock
Post by: David Paterson on February 05, 2018, 17:11:32
Robert - I'm overwhelmed - I was the guilty party in over-loosening the locking knob, and I was the one who mashed that screw-head . . . but I was 100% correct about one thing - I thought the repair was far too difficult to do by myself, and it was.

Thank you very,very much. I owe you, bigtime.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Akira on February 05, 2018, 18:19:31
Wow, Robert, that's an impressive job!

Dave, glad your problem is solved.
Title: Re: ArcaSwiss ballhead won't lock
Post by: simato73 on February 05, 2018, 23:22:11
Wow!
I am glad to be part of Nikongear, only here do you find this kind of knowledge and goodwill.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Bjørn Rørslett on February 05, 2018, 23:25:19
Amen to that :D
Title: Re: ArcaSwiss ballhead won't lock
Post by: David Paterson on February 06, 2018, 01:23:49
Wow!
I am glad to be part of Nikongear, only here do you find this kind of knowledge and goodwill.

You must have been reading my thoughts. I was just running through all the very enjoyable times, good friendships made, and knowledge, expertise and technique exchanged freely  -  all under the big umbrella which is NikonGear. I don't think I have experienced anything else quite like it, and I expect the friendships and the memories to last the rest of my life. I marvelled at how easily we all got along - 15 to 20 individuals mostly strangers to each other - during the Lofoten and Scotland weeks. But those were no flukes; mutual goodwill is NG's principal product.

(If only we could get a few of the world's politicians to join; they would soon learn how to behave.)
Title: Re: ArcaSwiss ballhead won't lock
Post by: richardHaw on February 06, 2018, 02:49:29
great service  :o :o :o

you should be making OEM parts
Title: Re: ArcaSwiss ballhead won't lock
Post by: Hugh_3170 on February 06, 2018, 11:35:50
We can but dream David. 

But I agree with the rest of your sentiments.  Great outcome.

................................................

(If only we could get a few of the world's politicians to join; they would soon learn how to behave.)
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 06, 2018, 15:32:20
Thank you for all the kind words, I just enjoy fixing stuff!  ;D

For those who are interested in the mechanics, Richard and others...

The internals of this Arca Swiss Monoball head are quite interesting.

The ball itself is beautifully turned from aluminium, probably magnesium. The gripping mechanism for the ball is very simple, although I wasn't able to access it completely, it seems the shaft with the main tensioning and locking knob has both left and right hand threads, probably M8 ISO thread.  When clamping, there is a semi concave clamp which grips the lower half of the ball on two sides and also presses it upwards into a similar concave pad at the top of the main body.  It's as simple as that.

The three security screws are a clever reversal of a countersink, hard steel, grip to tighten but cause a screwdriver to 'cam out' if an attempt is made to undo the screws.  I suspect while the main ball mechanism is simple and robust, it may be pretty close tolerances to assemble, hence the "keep out" screws.  There does not appear to be a spring in there.

The rotation clamp at the base is also very simple.  The three 3mm countersunk screws secure a inverted cone, when the clamping knob is tightened it clamps a corresponding collar against the cone, increasing friction until, when sufficient pressure is applied, it effectively locks.

The machining is to a very high standard, the finish of the internal parts is immaculate.  The damping is effected with thick, sticky grease, which I tried to avoid disturbing.

In short a joy to work on.
Title: Re: ArcaSwiss ballhead won't lock
Post by: CS on February 06, 2018, 16:19:10
Thank you for all the kind words, I just enjoy fixing stuff!  ;D

For those who are interested in the mechanics, Richard and others...

The internals of this Arca Swiss Monoball head are quite interesting.

The ball itself is beautifully turned from aluminium, probably magnesium. The gripping mechanism for the ball is very simple, although I wasn't able to access it completely, it seems the shaft with the main tensioning and locking knob has both left and right hand threads, probably M8 ISO thread.  When clamping, there is a semi concave clamp which grips the lower half of the ball on two sides and also presses it upwards into a similar concave pad at the top of the main body.  It's as simple as that.

The three security screws are a clever reversal of a countersink, hard steel, grip to tighten but cause a screwdriver to 'cam out' if an attempt is made to undo the screws.  I suspect while the main ball mechanism is simple and robust, it may be pretty close tolerances to assemble, hence the "keep out" screws.  There does not appear to be a spring in there.

The rotation clamp at the base is also very simple.  The three 3mm countersunk screws secure a inverted cone, when the clamping knob is tightened it clamps a corresponding collar against the cone, increasing friction until, when sufficient pressure is applied, it effectively locks.

The machining is to a very high standard, the finish of the internal parts is immaculate.  The damping is effected with thick, sticky grease, which I tried to avoid disturbing.

In short a joy to work on.

Let me just say that your adventures are a joy to follow!  8)
Title: Re: ArcaSwiss ballhead won't lock
Post by: FredCrowBear on February 07, 2018, 03:51:24
Very impressive, Robert!
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 08, 2018, 14:00:48
Thank you Fred.  ;D

The postie just called, a present and an item off of eBay for my next project, an Amp/Volt Meter for my proposed external power source for the D3.

The present is from David, a lovely book of photographs, I have't had time to enjoy them all yet but a quick flip through shows they are gems of some of my favourite bits of Scotland.  Thank you kindly David, your book will be greatly enjoyed and sit alongside my 'Picture of Everest' by Alfred Gregory.

My desk!

(https://farm5.staticflickr.com/4656/25278502437_0ff553da2e_b.jpg)
Title: Re: ArcaSwiss ballhead won't lock
Post by: David Paterson on February 13, 2018, 18:36:27
Well - my thanks to the man with the metal-working lathe and the skills to match. My ArcaSwiss ballhead arrived in today's post, impecccably packaged, and when tested with the heaviest outfit I could muster, it was smoother than ever and passed every test with flying colours.

Thank you, Robert.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 13, 2018, 22:06:57
That's great news David, I am so pleased, it's one thing pulling my own kit to pieces but with something as precious as that ball head, which wasn't mine,  I was very concerned it might not be a complete success.

I managed some time with clean hands to enjoy your book,  the pictures and commentary are first rate, well done.   It must have taken quite a while to amass those photographs, fitting that you used them together in the way you have.
Title: Re: ArcaSwiss ballhead won't lock
Post by: David Paterson on February 13, 2018, 23:26:11
Well - thanks again, on all fronts - you fixed my ArcaSwiss and you like my book - I don't think it gets better than this.   ;D

I've been thinking, from time to time, about your publishing project/problem. I don't know if there is a way - perhaps a plug-in - which lets Photoshop handle multi-page documents, but if there were, that would be a good way to go. I'll do a bit of digging and see what I can come up with. What you need to do, I think, is to produce a large, multipage pdf - probably the best vehicle for online publishing but not an area I know a lot about. I'll get back to you.
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 14, 2018, 00:51:53
I need to explain in some detail before you dig.

Will PM tomorrow, family commitments allowing...  It's a long term project which has stalled, mainly because I have reached a stage for which I have no experience.
Title: Re: ArcaSwiss ballhead won't lock
Post by: richardHaw on February 14, 2018, 03:05:15
more pictures  :o :o :o
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 14, 2018, 09:47:24
Sorry Richard I don't have any more photographs, except less good versions of those I have shown.  There wasn't much opportunity to get any of the inside, I only removed the base with the three screws which were originally I believe M3 x 0.5mm Philips and replaced them with three 3mm stainless steel M3 screws as described.  You couldn't see the rotation locking inverse cone really well enough to photograph it.  I will make a simple sketch so you can see the layout and principle of the internals later today.
Title: Re: ArcaSwiss ballhead won't lock
Post by: richardHaw on February 14, 2018, 10:15:49
Sorry Richard I don't have any more photographs, except less good versions of those I have shown.  There wasn't much opportunity to get any of the inside, I only removed the base with the three screws which were originally I believe M3 x 0.5mm Philips and replaced them with three 3mm stainless steel M3 screws as described.  You couldn't see the rotation locking inverse cone really well enough to photograph it.  I will make a simple sketch so you can see the layout and principle of the internals later today.

Thanks! just curious at what's inside  :o :o :o
Title: Re: ArcaSwiss ballhead won't lock
Post by: Seapy on February 14, 2018, 11:25:00
Here we go...

Extremely rough sketch on back of an envelope!

(https://farm5.staticflickr.com/4650/39548979364_1719685042_b.jpg)

Sorry about the poor quality of the sketch.

The rotation clamp is secured with three tamper resit screws (not shown) accessible through the base, it is a split ring, one end anchored, the other end clamped by the rotation clamp screw.

The ball clamp must be anchored somewhere at the upper part, maybe a fulcrum ridge in the main body, it wasn't visible without removing the rotation clamp, which wasn't really an option without risking damage  to the clamp.

The left and right hand threads of the ball clamp were probably ISO M8 from what little I could see of them.  It really is very simple in there but beautifully machined.  All surfaces are immaculate.