p.2 #1 · Size of mounting hole on bottom of Canon DSLRs?
Charles: Thanks for the information about the thread size!
As you know, Class 1 generically called "Loose Fit" as its tolerance is the loosest/sloppiest. It is also used where hand assembly is required (versus using a wrench) - which may be why Class 1 is specified for this application.
Class 2 is called "Standard Fit." This tolerance is used for 90% of commercial and industrial fasteners.
Class 3 called "Tight Fit." It is used for close-tolerance fasteners, and is for applications where safety is critical. It requires the use of a tool to advance the threads.
The fact that Class 1 tolerance is used on the camera body threads is why the fit is so loose.
Reference books such as "Machinery's Handbook" gives dimensions for internal and external threads for various sizes and tolerances.
By the way, the "A" in the Class is for external threads (screws, bolts) and the "B" is for internal threads (nuts, camera tripod connections). So the screw/bolt is a 1/4-20 UNC Class 1A, the camera tripod socket would be a 1/4-20 UNC Class 1B.
p.2 #2 · Size of mounting hole on bottom of Canon DSLRs?
aborr wrote:
I think it's the 100 yen coin you guys mean. The one in my desk drawer used to live in my camera bag in the days when the bag contained manual focus 35mm bodies instead of DSLR's. The coin's as old as my MF 35mm bodies - It's a bit smaller in both diameter and thickness than an American quarter. I don't know if Japanese coinage has changed in design since I acquired my coins.
vivisha -
The other posters are right. The tripod socket on Canon cameras is a 1/4-20 UNC (Unified Inch screw thread, Course pitch.), same as the male thread on the small side of the Gitzo "disc". If the bolts you get from your hardware store don't fit it properly, you need a new hardware store. The closest metric standard size is an M6x1.0, which has too fine a thread to fit in the camera's socket. A 1/4" UNC bolt is real crude compared to any modern standard metric fastener that's close in size. ...Show more →
The 100 yen is much smaller than a quarter, unless they changed. The 10 yen is a large copper-clad coin.
p.2 #3 · Size of mounting hole on bottom of Canon DSLRs?
EB-1 wrote:
The 100 yen is much smaller than a quarter, unless they changed. The 10 yen is a large copper-clad coin.
EBH
My 100 Yen coins are bigger than an American nickel and smaller than an American quarter in diameter. They fit perfectly on various battery and motor drive covers on my old Pentax LX and Nikon F4 bodies, but maybe some other cameras used a "10 Yen standard" instead.
p.2 #4 · Size of mounting hole on bottom of Canon DSLRs?
I reckon the tripod mount was set in stone before UNC existed, I reckon it would be 1/4" Whitworth, which is very close to the current UNC standard, it definitely isn't metric.
p.2 #5 · Size of mounting hole on bottom of Canon DSLRs?
It looks like an older G56x series. Some had attached mounts with a should piece or swivel head etc. This site has great parts views with Gitzo part numbers.
p.2 #6 · Size of mounting hole on bottom of Canon DSLRs?
pw-pix wrote:
I reckon the tripod mount was set in stone before UNC existed, I reckon it would be 1/4" Whitworth, which is very close to the current UNC standard, it definitely isn't metric.
See my post above - I've seen the argument RE 1/4 BSW vs 1/4-20 a LOT of times, and it MAY have been BSW at one time (I have some OLD bodies where BSW seems to fit better), BUT I decided to spend the $50+ for the offical spec, just to put it to rest in my mind. It's 1/4-20 UNC
p.2 #8 · Size of mounting hole on bottom of Canon DSLRs?
I've been away from machining for over 10 years, but IIRC, 1/4-20 is equal to M6x.75 They aren't exactly the same, but for ordinary applications, they are the same. The difference amounts to a difference of a few thousandth of an inch per inch of thread. If you have a really long thread and really long nut, they will bind after a certain length.
p.2 #9 · Size of mounting hole on bottom of Canon DSLRs?
runamuck wrote:
I've been away from machining for over 10 years, but IIRC, 1/4-20 is equal to M6x.75 They aren't exactly the same, but for ordinary applications, they are the same. The difference amounts to a difference of a few thousandth of an inch per inch of thread. If you have a really long thread and really long nut, they will bind after a certain length.
No. The ".75" designation means a .75mm thread pitch. That's roughly 34 threads per inch. You'd need an awfully big wrench to get it to mate with a 20 tpi 1/4-20 fastener.
