Sparta WD006 disassembly help needed: Cover removal

[JohnTN]

On 18/08/2024 at 12:15, Alan64 said:

It appears that there's room enough to add extras under the steel washer...

You'd be amazed at how easy they are to make; well, not particularly easy, although not particularly difficult.  

Clean and re-grease throughout with Super-Lube, if you'd like.  It's not mandatory, or is it?

Then there are needle-thrust bearings, with mini-rollers integrated, splayed round, to place here and there perhaps...

My Porta I, so far, requires only one of those for each axis, and that happens to be at the same point as your own adjustment, not actually within the axes where light does not shine.

The bearings should be sandwiched within two phosphor-bronze washers, like this...

 

That one was for the DEC-axis of my Meade LX70 EQ5-class equatorial mount.  I will need to make two of those sets for the Porta I, one set for each axis.

Inside the axes, I will make those same washers, two for each axis, but without the bearing.  I could include bearings however, if the spacings and other will allow.  The increase would be negligible.

Such will eliminate any jerking, hesitations, stiffness, catching on this and that, during the motions.  Then, all aluminium surfaces having to do with the axes' motions should be smoothed and polished.

Iron-based metals, including stainless-steel, should not bear against aluminium surfaces, like this one...

Take from that what you might, and for an improved experience.

Concerning addition of your bearing sandwich under the steel washer, I have some questions.

When I adjusted the nut last time, I noticed that the washer does move sometimes when the axis is rotated and even more so when I rotate using a side load.  So possibly the more load is on the mount, the more tendency to unscrew.  Now the question.  Do you think adding your design bearing sandwich would eliminate entirely the tendency for the washer to move?  Is it possible that this would increase the load carrying ability of the mount?

Would there be room for it without removing other parts of the "stack?"

Third question.  I think you said you order the bearings, but how do you make the phosphor bronze washers?

Thanks,

John

 

[Alan64]

3 hours ago, JohnTN said:

I understand.  And is it true that all 4 set screws (two on the bolt side and two on the non-bolt side) have to be loosened to free the cam so it can be adjusted? 

Do the cams require adjustment?  The four set-screws, two pairs, merely lock the cams in position, top and bottom. 

Are the worm-shafts difficult to turn?  

[Alan64]

13 hours ago, JohnTN said:

Concerning addition of your bearing sandwich under the steel washer, I have some questions.

When I adjusted the nut last time, I noticed that the washer does move sometimes when the axis is rotated and even more so when I rotate using a side load.  So possibly the more load is on the mount, the more tendency to unscrew.  Now the question.  Do you think adding your design bearing sandwich would eliminate entirely the tendency for the washer to move?  Is it possible that this would increase the load carrying ability of the mount?

Would there be room for it without removing other parts of the "stack?"

Third question.  I think you said you order the bearings, but how do you make the phosphor bronze washers?

Thanks,

John

 

That washer that you see under the lock-nut is not to be discarded, by the way, or replaced.  It would cover and bear against anything placed underneath it.  If it moves, it moves.  Try a new lock-nut if the axis loosens up whilst rotating.

I haven't even made the washers yet for my Vixen Porta I mount.  I'm waiting on sanding-drums for my Dremel.  Do you have a scroll-saw, like this...

I make my own in a roundabout way, without a metal lathe...

I use fine German-made blades, the non-pin type; jewellers' blades.  Sometimes an adaptor is required for those.  

[globular]

G1257?

[Alan64]

13 hours ago, globular said:

G1257?

Yes, that's the model number, and long since discontinued, yet one of the very best of its manufacturing era.

[JohnTN]

On 28/08/2024 at 20:15, Alan64 said:

Do the cams require adjustment?  The four set-screws, two pairs, merely lock the cams in position, top and bottom. 

Are the worm-shafts difficult to turn?  

The worm shafts turn easily, but there is a little lash.  Probably acceptable for now, at least until I get the wobble problem ironed out.

 

[JohnTN]

On 28/08/2024 at 20:45, Alan64 said:

That washer that you see under the lock-nut is not to be discarded, by the way, or replaced.  It would cover and bear against anything placed underneath it.  If it moves, it moves.  Try a new lock-nut if the axis loosens up whilst rotating.

I haven't even made the washers yet for my Vixen Porta I mount.  I'm waiting on sanding-drums for my Dremel.  Do you have a scroll-saw, like this...

I make my own in a roundabout way, without a metal lathe...

I use fine German-made blades, the non-pin type; jewellers' blades.  Sometimes an adaptor is required for those.  

I do not have a scroll saw.  That looks like a great way to make the washers.  Thanks for the extra details.

I went to Home Depot yesterday and bought the last two M8 nylocs they had, with two different nylon colors.  They were zinc coated, not my favorite.  We shall see...  It must have been Lowes where the Hillman nuts were.  I was going to go there after a Physical Therapy session but my girlfriend texted me saying there was a snake in the kitchen and I needed to come right home!  You would have thought it was an anaconda from the way she talked!  Of course it had disappeared by the time I got there.  Later it surfaced again in the same place.  It had to be the smallest snake I had ever seen!  I swept it into a large storage tub and took it outside.  She was greatly relieved.

 

[Alan64]

4 hours ago, JohnTN said:

I do not have a scroll saw.  That looks like a great way to make the washers.  Thanks for the extra details.

I went to Home Depot yesterday and bought the last two M8 nylocs they had, with two different nylon colors.  They were zinc coated, not my favorite.  We shall see...  It must have been Lowes where the Hillman nuts were.  I was going to go there after a Physical Therapy session but my girlfriend texted me saying there was a snake in the kitchen and I needed to come right home!  You would have thought it was an anaconda from the way she talked!  Of course it had disappeared by the time I got there.  Later it surfaced again in the same place.  It had to be the smallest snake I had ever seen!  I swept it into a large storage tub and took it outside.  She was greatly relieved.

 

Yes, snakes have been a problem here on a few occasions as well, over the years.  Here's a copperhead, a pit-viper, although the mildest of same, sunning itself in my driveway right in front of my house, five years ago...

I drove it away, and haven't seen it since.  At one point I was about two to three feet away, with our staring at one another.

At other times it was one or two non-venomous, and in the house.  

The best scroll-saws have a solid table, not of flimsy stamped steel, which are prone to twisting and warping.  For example, this one, of stamped steel, an old Harbor Freight "Central Machinery", was abandoned to the elements well over a decade ago, then almost twenty possibly...

You wouldn't want that one of course, nor a new one of that type.  This is a new one, with a similarly shaped table, yet a solid table, likely of cast iron...

https://www.harborfreight.com/16-in-variable-speed-scroll-saw-71113.html

...and at a great price.  The reviews, although scant, offer only praise for the wonder.  You would need an adaptor for the fine blades without pins, at that price. 

A rotary-tool, a Dremel, or a generic with above-average reviews, is required, along with mandrels and sanding-drums, as the saw will cut close to the circles described by the tool-steel tip of a compass, but you'll need to grind the rest of the way to the line, then sand and polish.  I wear reading-glasses to get very close whilst working.

Phosphor-bronze is ideally placed, and in its element, when continuously immersed in grease, Super Lube or other.  It will tarnish otherwise, just like copper and brass.  Phosphor-bronze is seemingly brittle, very slightly, but it's a tough metal.  It's the small amount of phosphorus added to bronze that gives the metal its characteristics.

[JohnTN]

5 hours ago, Alan64 said:

Yes, snakes have been a problem here on a few occasions as well, over the years.  Here's a copperhead, a pit-viper, although the mildest of same, sunning itself in my driveway right in front of my house, five years ago...

I drove it away, and haven't seen it since.  At one point I was about two to three feet away, with our staring at one another.

At other times it was one or two non-venomous, and in the house.  

The best scroll-saws have a solid table, not of flimsy stamped steel, which are prone to twisting and warping.  For example, this one, of stamped steel, an old Harbor Freight "Central Machinery", was abandoned to the elements well over a decade ago, then almost twenty possibly...

You wouldn't want that one of course, nor a new one of that type.  This is a new one, with a similarly shaped table, yet a solid table, likely of cast iron...

https://www.harborfreight.com/16-in-variable-speed-scroll-saw-71113.html

...and at a great price.  The reviews, although scant, offer only praise for the wonder.  You would need an adaptor for the fine blades without pins, at that price. 

A rotary-tool, a Dremel, or a generic with above-average reviews, is required, along with mandrels and sanding-drums, as the saw will cut close to the circles described by the tool-steel tip of a compass, but you'll need to grind the rest of the way to the line, then sand and polish.  I wear reading-glasses to get very close whilst working.

Phosphor-bronze is ideally placed, and in its element, when continuously immersed in grease, Super Lube or other.  It will tarnish otherwise, just like copper and brass.  Phosphor-bronze is seemingly brittle, very slightly, but it's a tough metal.  It's the small amount of phosphorus added to bronze that gives the metal its characteristics.

Good to know.  Thanks for the additional information.  I saw one copperhead here, many years ago.  I don't like to see them around!

[Alan64]

On 31/08/2024 at 03:36, JohnTN said:

Good to know.  Thanks for the additional information.  I saw one copperhead here, many years ago.  I don't like to see them around!

There is a possibly grave danger to the elderly and very young, but the venom will only gimp up an adult of average health and constitution, for a while, a few days. 

One good thing in making the washers is that you can use metal-shears to cut along the outside of the lines.  Only the inner diameters require sawing out, grinding to the final shape inside and out, then sanding and polishing, the latter with #0000 steel-wool and lemon-oil.  Never force the saw, being in a hurry, as the blades will break.  The speed of the saw will need to be set to the highest setting, which isn't good, but necessary.

Edited September 1 by Alan64

[Alan64]

I apologise for not explaining earlier.  This area, again...

...is a tying-off.  The nut and washer act as a bow-tie, if you will, to hold the components altogether, so to keep them from sliding apart and falling on the ground...

[JohnTN]

8 hours ago, Alan64 said:

I apologise for not explaining earlier.  This area, again...

...is a tying-off.  The nut and washer act as a bow-tie, if you will, to hold the components altogether, so to keep them from sliding apart and falling on the ground...

Thank you for the exploded photo of the assembly.  It helps my understanding.  It looks like there is a lock nut and washer on each end of a shaft.  Possibly many of these similar mounts have the same design.

[JohnTN]

I have had better success improving this mount since my last writing.  In summary, the adjustments for play and tightness on this Sparta mount are accessed by removing the dovetail saddle (4 bolts) for the altitude axis and by lifting the rubber cover exposing two bolts which can be removed to access the azimuth axis.  I adjusted both axes a couple of times but they loosened up after a short time.  I removed the factory M8 locking nuts and replaced them with the ones shown, which came from Home Depot.  I had to order them but they do not charge shipping.  The nut with the black insert is the original and with the white insert is the Home Depot replacement.  I adjusted them a little too tight at first but went back in and loosened them 1/16 to 1/8 turn.  This still left the altitude axis a little tight and I went back in and loosened it a bit.  At the same time I noticed the azimuth axis had a little wobble so I tightened it a bit.  The new lock nuts are better but still maybe not good enough! 

[JohnTN]

The Nuts tried above did not work out so well.  The one on the azimuth loosened as before and the one on the altitude actually tightened to the point the altitude would barely move!

So I tried another type I had on hand, these from Lowe's and plated instead of Stainless.  They look a lot like the two already tried so I have little hope...

While I was disassembling (I'm getting pretty fast at it!), I decided to take the blue base off to see what the other end of the axis looks like.   It appears to be only a screw head, driven in tightly.  I did not go any further, as it appears this has nothing to do with the adjustment in which I am interested.

 

 

Edited Wednesday at 00:59 by JohnTN
to correct my error