To sell my 383L+ and buy the ASI1600 mono cool, or not too ?

[Davey-T]

There were some posts about it a while ago when it came out, should come up if you do a search.

Dave

[RuralBill]

2 hours ago, Davey-T said:

There were some posts about it a while ago when it came out, should come up if you do a search.

Dave

Well as you suggested I did a search, and they seem to be the dogs ****, Sounds like just what I need,,just wonder if they do an adapter for a WO ZS66 frac, if so I may upgrade that aswell as my SCT.

cheers

Bill

[RuralBill]

10 hours ago, ChrisLX200 said:

As I understood it the 'brake' only prevents rotation of the spindle so when pointed towards the zenith it won't unwind by itself, it has no effect on the 'gripping friction' between spindle and focus tube. However, if you have a stepper attached this would/should prevent unwanted rotation anyway so it's a bit redundant. The key adjustment is to the other screw(s) which governs the initial pressure. 

It's a bit late now but I usually recommend the Revelation R&P SCT focuser, inexpensive (comparitively) but it's well made, stiff and doesn't slip. Very pleased with mine.

ChrisH

Hi Chris,

well you were spot on about the function of the screw it is just a brake, and not a tension screw as I thought.

i have been in the garage testing again, and found the problem, the two hex screws that hold the shaft untit to the focuser body are tightened at the factory and was told that they should not me touched, well after looking closely, one side was not flush with the focuser body there was a 1 mm gap, so I though I have nothing to loose if I see if they are tight, and they were both loose, one side by 2 full turns and the other by half a turn, so tightened right up and guess what.....absolutely perfect now, no brake needed, and holds a tone of weight....well not quite a ton, but you get the drift. By having the brake on full before, it was partly compensating for the lack of friction, but still was not holding.

so all along there was not enough shaft to plate friction there, the other thing was that when I put weight on the drawtube with it pointing straight up and forced it down with my hand, the focus knobs did not spin as I thought they should, it just slipped down, but now they spin perfectly, but it takes a lot more force to move it down now.

 Infact it used to slip slightly under just the weight of the 2" to 1.25" reducer, if I had no brake on, now I can put about 1.5lb of weight before it moves at all with no brake.......unbelievable difference.

I have set a little brake on just so as not to put all the pressure and load on the motor to hold it, although the motor does hold it all fine, have set the brake so it just about holds the weight when on the bench without the motor fitted, do you think that will be ok To run with a little brake on ??  or should I let the motor hold it..??

works like a dream now, can't believe I nearly went and advertised it and bought a Baader, glad I re checked it over, what a mistake that would have been.

thanks for your help and advice.

Bill

[ChrisLX200]

Glad you have it sorted Bill. If possible I would run it without the brake, it does depend a little on the motor driver but normally (?) the coils remain energised when it is powered up but not moving and that provides a holding torque. If you use the brake you will just be adding to the friction and increasing the backlash in the process.

ChrisH

[RuralBill]

I have the Starizona Microtouch stepper, seems very good to be honest, and yes there is a holding torque when powered on.

forgive me for the questions, but how does the brake being on add backlash ? ...as you can tell this is all a bit new to me. 

Bill

[ChrisLX200]

There will be more resistance before the focuser starts to move, more torque is required which will mean the motor will turn a little more before everything starts moving. It's what I found with my Baader Crayford anyway while trying to get it to work!

ChrisH

[RuralBill]

24 minutes ago, ChrisLX200 said:

There will be more resistance before the focuser starts to move, more torque is required which will mean the motor will turn a little more before everything starts moving. It's what I found with my Baader Crayford anyway while trying to get it to work!

ChrisH

Ok, understood

thanks again for all the advice

Bill

[geordie85]

On 29/06/2016 at 16:11, RuralBill said:

Hi all,

Am reading lots of good things about the new ASI1600, and people comparing with the Kodak 8300 sensor, say it is better....

i have an Atik 383 mono, but is very heavy for my set up, so would swapping for the new ASK1600 be a good thing..??

i realise that the exposures would have to be a lot shorter, but people's opinion would be interesting.

any thoughts

cheers

Bill

Hi Bill

I'm curious to know what decision you made in the end as I'm currently thinking about doing the same thing. The 383L is just too noisy for my liking especially in o111 even at -20. 

[GTom]

On 10/14/2016 at 15:56, geordie85 said:

Hi Bill

I'm curious to know what decision you made in the end as I'm currently thinking about doing the same thing. The 383L is just too noisy for my liking especially in o111 even at -20. 

Joining the "curious club" too! It's relatively easy to compare CCD to CCD according to specs, but a CMOS is a different kind of animal... I'd be interested, if the asi1600mm-cool can ever get to the 414ex-mono levels by binning and/or whatever measures it takes - other than increasing exposure time and grabbing a bigger scope...