ADM Saddle Tension Knob - Too Tight to Unscrew

[DRT]

I have a couple of ADM Saddles, each with double tension knobs, which provide a very secure way of attaching my 150 f/8 refractor and/or 200P f/5 Newt to an Alt-az mount but I sometimes have difficulty loosening the tension knobs to un-mount the scopes at the end of the night as my hand can't grip the knobs tight enough.

I have a wrench that is a hooked lever and a length of bike chain that can be used to loosen the tension knobs but it is a bit tricky to use when also ensuring I have a good grip on the OTA to avoid it crashing to the floor.

Has anyone else encountered this problem and come up with a clever solution?

[brantuk]

If you have a small piece of the dovetail bar extending from the front of the shoe - you can screw a small block of metal to the end of it but underneath to stop the scope sliding backwards in the main shoe when you loosen the tension knobs. The single knobbed  shoes from an upgraded Skytee mount are great for this - but a metal block screwed underneath is more permanent.

[Bizibilder]

Sounds as if you may be over tightening them in the first place.  They only need to be tightened by hand and should undo easily enough at the end of a session.  If something is "sticking" then you could try lubricating the threads with soft pencil lead (4B or 6B) as the graphite will act as a non-stick lubricant.

[Grotemobile]

http://www.amazon.co.uk/GRAPHITE-LUBRICANT-SPLINED-SCREWED-Quality/dp/B006EOK0BK/ref=sr_1_1?ie=UTF8&qid=1437211843&sr=8-1&keywords=graphite+grease

This is what U need. Swear by this

stuff.

Steve

[Stub Mandrel]

If you make a wrench with three  or four pegs in a triangle or square to fit in the grooves in the knobs, it might help, or a 'boa constrictor'.

[DRT]

If you have a small piece of the dovetail bar extending from the front of the shoe - you can screw a small block of metal to the end of it but underneath to stop the scope sliding backwards in the main shoe when you loosen the tension knobs. The single knobbed  shoes from an upgraded Skytee mount are great for this - but a metal block screwed underneath is more permanent.

Thanks - I already have protruding bolts at the ends of the dovetails for this reason. My worry is that if I loosen the knobs slightly too far with the chain wrench the scope could simply pull itself out sideways. One thing that just occurred to me is that I have been mounting and dismounting the OTAs in a horizontal position. Perhaps vertical would be safer as I could wrap an arm around the OTA and use the other hand to twiddle the knobs.

Sounds as if you may be over tightening them in the first place.  They only need to be tightened by hand and should undo easily enough at the end of a session.  If something is "sticking" then you could try lubricating the threads with soft pencil lead (4B or 6B) as the graphite will act as a non-stick lubricant.

I'm only hand tightening them so perhaps lubrication is the answer.

http://www.amazon.co.uk/GRAPHITE-LUBRICANT-SPLINED-SCREWED-Quality/dp/B006EOK0BK/ref=sr_1_1?ie=UTF8&qid=1437211843&sr=8-1&keywords=graphite+grease

This is what U need. Swear by this

stuff.

Steve

Thanks, Steve - at £6 from Amazon that is too difficult to resist trying - a tube is on its way now

[DRT]

If you make a wrench with three  or four pegs in a triangle or square to fit in the grooves in the knobs, it might help, or a 'boa constrictor'.

[brantuk]

If you mount an 1100 on an EQ mount then it's better to stand the scope on a stool next to the mount head and, with the weights off, bring the mount saddle round to hook onto the dovetail (while the scope's on the stool). Then slip the weights on the other end and hoist the scope up on the mount with ease. You're still doing it horizontal but it's a heck of a lot easier.

[msh1]

just get a set of pump pliers 

mark

[spaceboy]

Your doing them up too tight Derek ! I understand the need for them to be tight but too tight and you risk either snapping the nut or stripping the thread. I usually nip mine up then give them another 1/4 turn but check them regularly as the night gets colder.

[DRT]

Your doing them up too tight Derek !

I strongly suspect this is the problem. I have not been using these saddles for long and feel nervous when mounting and dismounting the scopes in case I have misaligned the dovetail or not tightened the clamp enough.

[Stu]

I strongly suspect this is the problem. I have not been using these saddles for long and feel nervous when mounting and dismounting the scopes in case I have misaligned the dovetail or not tightened the clamp enough.

It's all those six inch fracs you've been dead lifting Derek, you don't know your own strength

[damnut]

No,

Derek still has the original kkknobs on, not the easy grab, could have put some molyslip on the clutch too. Found out that the third puck is a diy on mine. As once released the three grub screws on Derek's there was no way to fit the saddle.

[glowjet]

Having trouble with the metal surfaces locking together on the ADM when you tighten. Find yourself some thick Alkathene, from such as an old kitchen milk or water jug, water fittings are made from this material, so you could try a plumbers to see if they have any thick washers with the appropriate size hole in.  if can find a piece, make a couple of washers with a 1/4" hole for the stainless steel studs. You will then find that it is easier to slacken the knobs back after tightening, as they should not lock up, try and see