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How to make my stage more solid?.

Posted: Fri Jun 09, 2017 8:44 pm
by Cyclops
Tho I love this scope, and realise it was a bargain buy (and it was second hand) the stage isn't totally solid. There's play in the block that holds the condenser and that connects the whole lot to the stand, yet the screws are tight. Last time I messed around with it to sort out the condenser misalignment I tightened all the screws, and yet when I move the fine focus when at around the closest focus point the stage moves slightly then springs back, so the subject swings temporarily out of the way. The scope is an Apex Practitioner, a brand I'd never heard of before.

Re: How to make my stage more solid?.

Posted: Fri Jun 09, 2017 8:47 pm
by billbillt
Do you have any photos of this you can post?..

BillT

Re: How to make my stage more solid?.

Posted: Fri Jun 09, 2017 8:59 pm
by Cyclops
billbillt wrote:Do you have any photos of this you can post?..

BillT
I'll see if I can get photos tomorrow, but basically the mechanism that moves​ the condenser up and down, a rack and pinion device, pretty standard I assume, attaches to the stand by two Alan keys, one at the bottom of the rack and pinion and one at the top. Those screws are tight, yet the stage which is consequently attached the condenser block, has some play in it.

Re: How to make my stage more solid?.

Posted: Fri Jun 09, 2017 9:30 pm
by Cyclops
This is a picture of a scope very similar to mine, from the same company. The red arrow points to the bottom screw that is easy to get to when the focus rail is racked up. The orange zigzag shows the area of movement (also on the opposite side of course). Imagine a piece of wood attached to a board with one screw. The piece of wood could pivot on that point if pressure is applied. Thats what seems to be happening but the second screw, the approximate position of which is shown by a blue circle, was also tightened.

Re: How to make my stage more solid?.

Posted: Fri Jun 09, 2017 10:32 pm
by apochronaut
So, the stage is moving laterally when you fine focus?

Re: How to make my stage more solid?.

Posted: Fri Jun 09, 2017 11:05 pm
by Cyclops
apochronaut wrote:So, the stage is moving laterally when you fine focus?
It's more of a judder. Like if someone tapped the scope while you were viewing and everything moves briefly

Re: How to make my stage more solid?.

Posted: Sat Jun 10, 2017 1:09 am
by apochronaut
Moving parts of microscopes are designed to move precisely and smoothly. On most of the parts, the lubricant used is a combination of lubrication and stickiness or a high tack. The stickiness acts as a clutch, holding back the movement somewhat, which confers precision and a smooth predictable motion..
Replacing such lubricants, known as damping greases, with regular grease or adding machine oil to the surfaces will usually cause a jerky motion. It sounds like this might be the case, here.

unless

it is all of a sudden moving on you after you have focused?...dropping, all of a sudden? this would likely be a tensioning problem. You might contact Brunel microscopes, the distributor, and find out how the tensioning on that one works. Likely, it is done by turning the focus knobs counter to each other but on some, that procedure , can break internal parts such as gears.

Re: How to make my stage more solid?.

Posted: Sat Jun 10, 2017 5:01 am
by PeteM
Another possibility - many scopes have the stage and condenser run on adjustable ball tracks. Typically ball bearings in a plastic retainer running on trackes. A combination of messed up lubrication, wear, and the tracks going out of adjustment will leave side play.

Best to disassemble the whole thing -- in a tray to avoid losing balls. You can usually see how the adjustment works, strip out the old lube if contaminated, put in a proper new lube as needed, and tighten things back up.

On many Japanese scopes (not sure if yours is of that era) you have to clamp the ball tracks slightly tight while screwing them down. Can be a bit tricky to get rid of play while not locking up the slides too tight.

Re: How to make my stage more solid?.

Posted: Sat Jun 10, 2017 8:08 am
by Cyclops
I really don't want to mess with it any further, I just want to get on with observing. It looks as tho the previous owner tried to do some adjusting on it and it went wrong, or its been dropped at some point. Either way it works as an amateur scope, it's just little niggles and I can't afford to have it repaired or get a new one.

Re: How to make my stage more solid?.

Posted: Sat Jun 10, 2017 6:57 pm
by billbillt
"Use it up, wear it our, make it do, or do without"

BillT

Re: How to make my stage more solid?.

Posted: Sun Jun 11, 2017 2:29 pm
by Cyclops
billbillt wrote:"Use it up, wear it our, make it do, or do without"

BillT
About sums it up! What I really want is low power, but I can't afford a new scope, plus low power scopes are binocular, and I only see through my right eye, hence the choice of a monocular scope

Re: How to make my stage more solid?.

Posted: Sun Jun 11, 2017 3:16 pm
by billbillt
Hello,

I am not sure what you mean by "low power". Your stand's specs claim you have a 4x objective.. That is pretty low, and standard.. I could not find anything on the tube length, but it should be marked on the objectives..

BillT

Re: How to make my stage more solid?.

Posted: Sun Jun 11, 2017 11:11 pm
by 75RR
About sums it up! What I really want is low power, but I can't afford a new scope, plus low power scopes are binocular, and I only see through my right eye, hence the choice of a monocular scope
Sounds as if you are talking about a stereoscope. You would lose the stereo/3D effect if you only observe through one eyepiece, but then again there is no 3D effect with the compound microscope you have anyway. What is it that you wish to observe?

It is possible to get objectives with a lower magnification than 4x and also eyepieces that magnify less than 10x - that would expand the low magnification range of your microscope.

Re: How to make my stage more solid?.

Posted: Mon Jun 12, 2017 7:12 am
by Cyclops
billbillt wrote:Hello,

I am not sure what you mean by "low power". Your stand's specs claim you have a 4x objective.. That is pretty low, and standard.. I could not find anything on the tube length, but it should be marked on the objectives..

BillT
Yes everything is standard, 160 tube length. But I'm more interested in the low power range that you normally get with stereoscopes, sub 100x. But like I said in another post I wasn't looking for a scope I just saw this one in a used goods exchange store at the time I had some spare money (a very rare occurance)

Re: How to make my stage more solid?.

Posted: Mon Jun 12, 2017 7:27 am
by Cyclops
But I also like this scope. ..

Re: How to make my stage more solid?.

Posted: Mon Jun 12, 2017 3:06 pm
by billbillt
Your stand will be fine.. I never said it wasn't.. I have never seen an objective less than 2x.. here is one method to get what you want..

http://www.microscopy-uk.org.uk/mag/ind ... ucing.html

BillT