Lost tripod mounting screw

Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help me out
either by telling me where I can get one or telling me what size screw
thread and length the screw is so that I can perhaps try to pick one up from
an ironmongers. Any help gratefully appreciated as my telescope is useless
without it :-(

Nats wrote:

Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help me out
either by telling me where I can get one or telling me what size screw
thread and length the screw is so that I can perhaps try to pick one up from
an ironmongers. Any help gratefully appreciated as my telescope is useless
without it :-(

1/4" Whitworth is a common thread for photo tripods (yes, even new ones
come with this 'old' type thread).
Without more details, it is difficult to tell which screw you mean.
Alan

--
To reply by e-mail, change the ' + ' to 'plus'.

A.Lee wrote:
Nats wrote:

Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help me out
either by telling me where I can get one or telling me what size screw
thread and length the screw is so that I can perhaps try to pick one up from
an ironmongers. Any help gratefully appreciated as my telescope is useless
without it :-(

1/4" Whitworth is a common thread for photo tripods (yes, even new ones
come with this 'old' type thread).
Without more details, it is difficult to tell which screw you mean.

I would suspect that it's different to a typical photo tripod mount
though - you wouldn't put a 6" reflector on one! Helios = Synta =
Chinese = Metric; at least all the hardware on my EQ3 and HEQ5 are
metric.

Nats:

I found a Helios Apollo 150 on the web, it looks like it uses a Synta
EQ5 mount (sold under numerous brand names). You might want to ask in
the CG5 (the Celestron name for the EQ5) Yahoo Group and describe
exactly which screw it is (I couldn't work it out from your
description):

http://tech.groups.yahoo.com/group/CG5/


Tim

In message , Nats
writes
Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help me out
either by telling me where I can get one or telling me what size screw
thread and length the screw is so that I can perhaps try to pick one up from
an ironmongers. Any help gratefully appreciated as my telescope is useless
without it :-(

My Skylux refractor has what looks like a 3/8" whitworth thread and I
suspect yours will be at least that.
Could you manage to take the mount to a good ironmongers? I find they
can be helpful by trying a bolt for size. If a bolt is not available you
can often buy threaded rod which you cut to length. You may then need
something welded on to act as a head of course. [Or a cross cut for a
hefty screwdriver?]
If you cannot find this solution try one of the little workshops on an
industrial estate. I had a battery clamp repaired recently for £2!
--
Best of luck,
John.

John wrote in :

Could you manage to take the mount to a good ironmongers? I find they
can be helpful by trying a bolt for size. If a bolt is not available
you can often buy threaded rod which you cut to length. You may then
need something welded on to act as a head of course. [Or a cross cut
for a hefty screwdriver?]


Or possibly some sort of wheel held between two nuts, or even just two nuts
screwed hard together

mike

Hmm Ive checked the screw more closely - seems to be a 3/8" Whitworth 2"
long screw I need which is the screw required to fit the EQ3 equatorial
mount (a Skyscan 2001) on to the tripod. I have found an ironmongery shop so
I will give it a try but whether you can just buy one bolt is doubtful! I
dont suppose anyone has one of these bolts with a hex head lying around that
they dont need?? :-)

"Nats" wrote in message
...
Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help me
out either by telling me where I can get one or telling me what size screw
thread and length the screw is so that I can perhaps try to pick one up
from an ironmongers. Any help gratefully appreciated as my telescope is
useless without it :-(

"Nats" wrote in message
...
Hmm Ive checked the screw more closely - seems to be a 3/8" Whitworth 2"
long screw I need which is the screw required to fit the EQ3 equatorial
mount (a Skyscan 2001) on to the tripod. I have found an ironmongery
shop so I will give it a try but whether you can just buy one bolt is
doubtful! I dont suppose anyone has one of these bolts with a hex head
lying around that they dont need?? :-)

"Nats" wrote in message
...
Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help
me out either by telling me where I can get one or telling me what size
screw thread and length the screw is so that I can perhaps try to pick
one up from an ironmongers. Any help gratefully appreciated as my
telescope is useless without it :-(
I'd actually guess that it is 3/8 UNC, rather than Whit. The difference is
the 'tooth form', which changes to 60 degrees, rather than 55 degrees.
There have been a lot of problems with cameras over the years, with 1/4
whit being the 'standard', but a lot of manufacturers using 1/4 UNC
instead. the American market, uses UNC as it's main thread 'standard', and
a lot of kit made for this market uses these threads (disk drive
mountings, are either 4-40UNC, or 3mm, according to the design market...).
I will almost certainly have one on the shelf in either thread. email me
directly.

Best Wishes

It ok thanks I got a couple of 3/8 Whitworth screws of various lengths from
a manufacturer and they work perfectly just need to cut one down and geta
washer and I'll be great to go. Thanks for your reply though.

"Roger Hamlett" wrote in message
...

"Nats" wrote in message
...
Hmm Ive checked the screw more closely - seems to be a 3/8" Whitworth 2"
long screw I need which is the screw required to fit the EQ3 equatorial
mount (a Skyscan 2001) on to the tripod. I have found an ironmongery shop
so I will give it a try but whether you can just buy one bolt is
doubtful! I dont suppose anyone has one of these bolts with a hex head
lying around that they dont need?? :-)

"Nats" wrote in message
...
Ive stupidly lost my tripod equatorial mount fixing screw for my Helios
Apollo 6" reflecting telescope and was wondering if anyone could help me
out either by telling me where I can get one or telling me what size
screw thread and length the screw is so that I can perhaps try to pick
one up from an ironmongers. Any help gratefully appreciated as my
telescope is useless without it :-(
I'd actually guess that it is 3/8 UNC, rather than Whit. The difference is
the 'tooth form', which changes to 60 degrees, rather than 55 degrees.
There have been a lot of problems with cameras over the years, with 1/4
whit being the 'standard', but a lot of manufacturers using 1/4 UNC
instead. the American market, uses UNC as it's main thread 'standard', and
a lot of kit made for this market uses these threads (disk drive
mountings, are either 4-40UNC, or 3mm, according to the design market...).
I will almost certainly have one on the shelf in either thread. email me
directly.

Best Wishes

"Nats" wrote in message
...
It ok thanks I got a couple of 3/8 Whitworth screws of various lengths
from a manufacturer and they work perfectly just need to cut one down
and geta washer and I'll be great to go. Thanks for your reply though.
The point is that 3/8 Whit, will fit a 3/8 UNC nut, but will reduce the
overall strength. The sides of the teeth are steeper on the Whit bolt, so
the thread doesn't engage right across the surface of the tooth. I would
be _very_ suprised if it was 3/8 Whit. Even in the UK, Whit as dropped by
most of industry, in the second World War, so that stuff would work with
kit from the US.
Fortunately, the base thread, doesn't need to be done up terribly tightly,
so the loss of strength probably won't matter...

Best Wishes

"Roger Hamlett" wrote in message
...

"Nats" wrote in message
...
Hmm Ive checked the screw more closely - seems to be a 3/8" Whitworth
2" long screw I need which is the screw required to fit the EQ3
equatorial mount (a Skyscan 2001) on to the tripod. I have found an
ironmongery shop so I will give it a try but whether you can just buy
one bolt is doubtful! I dont suppose anyone has one of these bolts
with a hex head lying around that they dont need?? :-)

"Nats" wrote in message
...
Ive stupidly lost my tripod equatorial mount fixing screw for my
Helios Apollo 6" reflecting telescope and was wondering if anyone
could help me out either by telling me where I can get one or telling
me what size screw thread and length the screw is so that I can
perhaps try to pick one up from an ironmongers. Any help gratefully
appreciated as my telescope is useless without it :-(
I'd actually guess that it is 3/8 UNC, rather than Whit. The difference
is the 'tooth form', which changes to 60 degrees, rather than 55
degrees. There have been a lot of problems with cameras over the years,
with 1/4 whit being the 'standard', but a lot of manufacturers using
1/4 UNC instead. the American market, uses UNC as it's main thread
'standard', and a lot of kit made for this market uses these threads
(disk drive mountings, are either 4-40UNC, or 3mm, according to the
design market...).
I will almost certainly have one on the shelf in either thread. email
me directly.

Best Wishes

from "Roger Hamlett"

"Nats" wrote
It ok thanks I got a couple of 3/8 Whitworth screws of various lengths
from a manufacturer and they work perfectly just need to cut one down
and geta washer and I'll be great to go. Thanks for your reply though.
The point is that 3/8 Whit, will fit a 3/8 UNC nut, but will reduce the
overall strength. The sides of the teeth are steeper on the Whit bolt, so
the thread doesn't engage right across the surface of the tooth. I would
be _very_ suprised if it was 3/8 Whit. Even in the UK, Whit as dropped by
most of industry, in the second World War, so that stuff would work with
kit from the US.
Fortunately, the base thread, doesn't need to be done up terribly tightly,
so the loss of strength probably won't matter...

I can't just let that mis-information go uncorrected!

The thread will most certainly be BSW. Whilst it is true that BSW in
general engineering was depricated in 1948 (well after WWII) in favour
of UNC, the British Standard 84 which describes BSW was last updated in
1956 and is still current and Camera/Tripod fixings have always been
BSW, wherever the camera originates - Germany/Japan/UK/USA.

Use of a UNC screw/bolt in a BSW nut should never be tolerated even
though the OD-Pitch is generally the same (the notable excption being
1/2" (BSW-12 UNC-13))

JG