7 replies to this topic

[cduston44]

We've got a 3" TOAD Van Slyke focuser that moves a bit roughly - it rattles and moves a little unevenly in some places. I've attached a picture of it, with some of the relevant parts (external bearings) and wear (on the "wheel side" of the tube), which might be relevant.

 

The focuser came with some maintenance instructions: "You should apply a light coat of WD-40 to the entire exterior [...] at minimum, you must apply a coat of WD-40 to the exposed (sealed) bearings, bearing pins, and drive shaft(s)."

 

I'm sure this has not been done in some time, but I'd really like to get this focuser back up and operational. However, I am a little nervous at applying WD-40 "everywhere" - for example, I think these focusers work just by friction between the wheels and the draw tube, so if I spray WD-40 "everywhere", won't that interfere with that? On top of that, I'm not completely confident that I can actually identify the "bearings, pins, and drive shaft".

 

For example, here's my attempt at that: Bearings are sticking out of the left side of that image, bearing pins are the axles of those bearings, and the drive shaft is the axle that travels between the two wheels you turn (I guess there are two of those, since we have rough and fine focus here).

 

So I guess what I'm looking for is confirmation of the maintenance instructions, confirmation that I've correctly identified the specific parts for minimum maintenance, and any additional advice that people have to get this focuser back into tip-top shape!

Attached Thumbnails

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[Philip Jodry]

WD40 is complete nonsense. Slobber your focuser with light grease and make waves.

[matt_astro_tx]

You could attempt to contact Paul.  BFO@OBSERVATORY.ORG

 

Here's the web page for the TOAD3 focuser:  http://observatory.org/toad3.htm

Edited by matt_astro_tx, 06 February 2023 - 01:27 PM.

[luxo II]

By all means use a solvent to clean the parts - ie remove dirt and grit, which are probably the cause of what you experience - in particular the roller and the flat contact surface driven by the roller. 

 

However it should be wiped off and allowed to dry - leaving solvent or grease anywhere will simply accumulate more dust and grit especially on the roller and its mating surface and in bearings.  Considering how lightly loaded the bearings are and the slow speed of movement, they'll never wear out in a lifetime even with no lubricant.

 

NB I have a VSI turret, much treasured.

Edited by luxo II, 06 February 2023 - 07:50 PM.

[cduston44]

WD40 is complete nonsense. Slobber your focuser with light grease and make waves.

Do you have a suggestion for a light grease to use? i.e. https://www.dupont.c...ure-grease.html ?

Edited by cduston44, 08 February 2023 - 01:21 PM.

[cduston44]

You could attempt to contact Paul.  BFO@OBSERVATORY.ORG

 

Here's the web page for the TOAD3 focuser:  http://observatory.org/toad3.htm

I have tried that and he did not respond. That was several years ago, but I got the message pretty loud and clear.

[cduston44]

Sorry for asking the nitty gritty, but I am not one who should actually be playing with telescope parts without being really sure of what I'm doing...

 

By all means use a solvent to clean the parts - ie remove dirt and grit, which are probably the cause of what you experience - in particular the roller and the flat contact surface driven by the roller.

 

However it should be wiped off and allowed to dry - leaving solvent or grease anywhere will simply accumulate more dust and grit especially on the roller and its mating surface and in bearings.  Considering how lightly loaded the bearings are and the slow speed of movement, they'll never wear out in a lifetime even with no lubricant.

 

NB I have a VSI turret, much treasured.

Ok, so WD-40 to clean the flat bit on the tube (draw tube?), and "the roller", by which what do you mean - the axle going between the two knobs, or are you suggesting some kind of disassembly to get at whatever is actually making contact with the draw tube?

[luxo II]

That’s the roller, yes, and disassemble to clean the flat surface on the side of the drawtube.

Any dust/grit on that flat surface or the roller causes the bumpy action you experienced. The one thing you don’t want in there is great or anything else that will collect and hold grit.

Edited by luxo II, 08 February 2023 - 10:04 PM.