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tripod bolt specs on 8SE mount

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#1 C8er

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Posted 07 February 2013 - 02:41 PM

Hi.

Can anyone tell me what specs the three bolts are that connect the 8SE tripod to the single arm mount? They look like they might be 3/8 16 but I'm not sure.

Cheers and Thanks in advance.

#2 barbarosa

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Posted 07 February 2013 - 03:26 PM

The SE and CPC mounts use 3/8" -16.

From the Celestron knowledge base-

What are the most common bolt sizes for Celestron single and double arm (fork) mount bases and wedges?


Answer A great number of old and new Celestron single and double arm (fork) mounts, tripods and wedges are attached to one another using just two sizes of bolts.

Most mounts are attached to the tripods by use of 3/8 – 16 bolts.
Most wedges are attached to tripods by use of 5/16 – 18 bolts.

Since most mounts are tapped for the 3/8 -16 bolts, most mounts attach to wedges by use of the same bolts. The top “hole” on the wedge plate is usually a slot for easy positioning and tightening of the three bolts.

Many of the original wedge bolts are Allen heads, while many of the original tripod bolts are knobbed.

#3 Geo.

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Posted 07 February 2013 - 05:08 PM

Yes, 3/8th" 16TPI, BUT NO LONGER THAN 3/4"! Too long and you'll be paying me $40 for a new RA gear.

#4 C8er

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Posted 07 February 2013 - 06:23 PM

Thanks George and Barbarosa. You've told me what i needed to know. I have gone and bought three 3/8 16 bolts short enough to grip the threads inin the mount but not to go through into the gear chamber inside the mount base. And I see the three spare threaded 5/16 holes in the se tripod head for wedge attachment bolts.

Many thanks fellas.

#5 Tel

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Posted 07 February 2013 - 08:03 PM

Just curious but that's a surprise to me !

I would have though that since Celestron's production operation moved to China, all threading, post 2005/2006, would have now been metric. Certainly this is the case when buying "Bob's Knobs" for the 8SE's secondary.

You live and learn ! :graduate:

Best regards,
Tel

#6 C8er

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Posted 07 February 2013 - 09:03 PM

Hi Tel.

My SE was new 6 months ago and still uses those non metric tripod bolts.

Cheers.

#7 barbarosa

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Posted 07 February 2013 - 09:03 PM

China makes zillions and zillions of United Thread Standard (UTS common US sizes) fasteners (heck they may make Whitworth too), so there might not be a cost basis for switching to metric. If they did switch then older and newer mounts could not be interchanged. The continued use of 1/2 -20 for cameras and tripods is another example.

Will they change? I have no idea. I thought that the US was going to convert decades ago. Instead we get our wine in 750ml bottles instead of "fifths". It was all a sneaky plot because a fifth = 757ml.

The real reason we never converted here was that the NFL couldn't deal with the problem of a 91.44m field. "First in 9.144 on their own 35.576" :foreheadslap:

#8 sonny.barile

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Posted 07 February 2013 - 09:31 PM

Im a designer in the US. My company has other divisions in Europe. When I try to convert my designs over to our EU plants I run in to some trouble. Most US mechanical blueprints use 3 place decimals. If you understand engineering drawings you probably know what a tolerance is. When I state something is .250 long just as written here, it means the dimension can be +.005"/-.005"

In other words the length can be anywhere from .245 to .255

When i convert the number it looks more like this: 6.350 +&- .127

If I didnt want such sloppy looking numbers I would need to redesign the product. This would mean more engineering time, new tools, new tooling, new fixtures, new inspection methods, new inspection tools, new packaging, and new quality assurance paperwork for regulated industries.

The cost would be astronomical.

#9 Tel

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Posted 08 February 2013 - 04:18 AM

Thanks for the information, David and Sonny. What a mixture though for the average buyer to contend with !

I think probably the only non-metric measurement we've retained over here is distance in miles, but which one of our illustrious members of the European Parliament even sought to change, at, of course, phenomenal cost. Luckily the proposal was rejected.

But then again these are the guys who set our standards, one of which, (now sensibly repealed), was once applicable to the "straightness" of the "Euro-banana" and thus, if meeting the appropriate criterium, could be deemed fit for sale ! :confused:

Best regards,
Tel

#10 sonny.barile

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Posted 09 February 2013 - 05:32 PM

I wish the whole world used one standard. I also wish we could use the same electrical outlets.

#11 Geo.

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Posted 12 February 2013 - 09:52 AM

Yeah, when the black helicopters fly.:crazy:

There are a lot of restraints on more unification, including a large manufacturing and durable goods base that's imperial. Most major new products in the U.S. use metric, but small manufactures don't want to put the capital into new machinery, so it will take a few centuries more to wring imperial out of the system. For example, Even when a Nexstar dies it and its imperial threads can get recycled.

As much of the U.S. is still imperial, imports from Asia often use imperial for better market penetration. OTOH, U.S. manufacturers who wish to export have to go metric. It should sort itself out eventually. And consider the plight of those Brits who can't source imperial easily in the U.K. If it wasn't for the U.S.'s backwardness, where'd they get this stuff?

Celestron has a big user base with 3/8-16 threads in their scope's mounts. Converting to, say 10mm, means that base is no longer part of the market for the tripod or making and inventorying two models, dual assembly operations, returns and possible damage to mounts. That's a lot of disincentives to change.

So take comfort in the fact that you can pass your multiple standard fasteners, tape/die and tool collections on to the next generation and they won't gather dust.

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#12 barbarosa

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Posted 12 February 2013 - 02:05 PM

Yeah, when the black helicopters fly.:crazy:


Long ago and far away when I was flying OD helicopters, dimensions were in inches (simple & decimal fractions), fuel was dispensed in gallons but displayed in pounds, we measured distance in meters, altitude in feet, and speed in knots. Some how it all worked, :scratchhead:but is surely wasn't rational.






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