PDA

View Full Version here: : Counterweights Lock screws


multiweb
12-12-2012, 06:17 PM
Anybody knows where I can buy those little plastic wing knobs that go on the end of the lock screws threaded into the counterweights. I'm forever breaking the freakin' things. I guess the plastic gets brittle with age and UVs? ... :shrug: like me. Thanks in advance. :thumbsup:

mithrandir
12-12-2012, 06:33 PM
For your G11? Robin Casady has beaut stainless steel ones. I don't know if they will fit Losmandy weights. You could ask it he'd make ones if they don't
He also has a replacement for the Losmandy safety stop, another nice bit of SS.

Barrykgerdes
12-12-2012, 06:46 PM
Hi Marc

What thread are they. I can make them with aluminium round knobs

Barry

midnight
12-12-2012, 08:26 PM
Watching with interest. I have now snapped 2 of the blighters on my Losmandy 21lb counterweights due to incorrect storage :(.

D...

marki
12-12-2012, 08:34 PM
Would be easy (and cheap) to machine some up in Ali plus you get a choice of shape and finish.

Mark

mithrandir
12-12-2012, 10:26 PM
The 21lb counterweight bolts look like 3/8" 16TPI (UNC) steel, 2.9" plus the head, threaded for 1.5". I can't be sure what thread it is but in Losmandy style it will be some US standard. The have a nylon bit on the end to stop scratching the counterweight bar.

I'd be a bit sus about using aluminium. Losmandy and Casady both use steel.

Could someone weld/braze a handle onto the head of the broken ones?

If you break off the rest of the plastic is it a hex head that you could tighten with a spanner?

multiweb
13-12-2012, 08:09 AM
Thanks for the feedback guys.

I broke both my 11 and 21lbs... The threads are the same but one lock screw is obviously a little longer on the 21.

Did a little more googling last night and there seems to be a pletora of choices (http://www.google.com.au/search?q=butterfly+knobs&hl=en&tbo=d&rls=com.microsoft:en-au&source=lnms&tbm=isch&sa=X&ei=bf3IUMe-HpGciQeC7YG4Bg&ved=0CAQQ_AUoAA&biw=1920&bih=972#hl=en&tbo=d&rls=com.microsoft:en-au&tbm=isch&sa=1&q=wing+knob+replacements&oq=wing+knob+replacements&gs_l=img.3...18163.20225.4.21208.12 .12.0.0.0.0.202.1281.7j4j1.12.0...0 .0...1c.1.onD0mrK_peM&bav=on.2,or.r_gc.r_pw.r_qf.&bvm=bv.1355272958,d.aGc&fp=36b87e91ee3f8e3f&bpcl=39942515&biw=1920&bih=972) for the heads. I like the three wing types.They're more compact and look solid. I think the problem with the existing losmandy is the two wings design. Something like this (http://rackboys.com/products/8487/Thule-Replacement-3-Wing-Knob-M6-Low.html)would be ideal.

Might look on eBay then stick a small pin through it. Quick fix.

Ajemsa
13-12-2012, 08:46 AM
These locations might have what you want:

http://www.ddbarry.com.au/products.htm

http://australia.rs-online.com/web/c/enclosures-storage-material-handling/knobs-equipment-handles-hand-wheels/knobs/

http://www.smallparts.com.au

Andrew

Barrykgerdes
13-12-2012, 09:34 AM
Give me the old bolts and I will make new heads for them.

The bolt does not usually tighten directly onto the shaft some have nylon inserts like Andrew says. Trevor has my G11 counter weights so I can't check them but all the counterweights I have seen have a cylindrical steel insert that actually makes contact with the shaft.

Barry

PS If the bolts have nylon inserts this will probably be the main cause of knob breakage. Getting the nylon to grip the shaft will require much greater pressure than a steel insert (nylon has a much lower coefficient of friction) BG

multiweb
13-12-2012, 11:43 AM
Thanks Andrew - I'm sure I'll find something there. :thumbsup:


Half of the hole in the counterweight actually meshes with the shaft which in my case is threaded so I don't have to tighten much. It's just old age I think.

Poita
13-12-2012, 11:46 AM
Mine are snapped off too.

mithrandir
13-12-2012, 02:57 PM
Do they stock US fittings? Losmandy uses those.

Ajemsa
14-12-2012, 08:12 AM
You got me thinking on that one. I know I obtained imperial sizes in the past but I can't see them on the websites. I suggest that you call/email them as they might still have them. Otherwise, they may be able to direct you to another supplier.

John0z
19-12-2012, 08:59 AM
I have a GM8. I had a look at the lock bolt for the 11lb counterweight. It is 3/8" 16tpi, threaded for the bottom section only - about 7cm long. The bolt would be available from Bunnings - since they also carry imperial sizes. The only thing is to make a handle for it - which should be possible, I might have a look at doing this. By the way, the end-bit is not nylon, at least in mine, but probably Acetal/Delrin. I dropped the bolt while trying to measure the thread and a little bit chipped of the end, nylon would not do this.

The original looks like a press-fit onto a round head, but that would be just a guess.

-John