EQ6 counterweight shaft mod

[peter_4059]

I'm wondering if anyone here has contemplated or done this mod to their EQ6.
http://www.astro-rubylith.com/product.sc?categoryId=1&productId=18

It looks like quite a good solution to extend and stiffen up the shaft but I'm not sure how long the threads in the Dec shaft nut would last.

This wouldn't be hard to do locally if you could find a machine shop to cut the threads and turn the shaft for you.

[Marko of Oz]

I bought a 20" length of 18mm round bright steel from the local bolt n steel sales shop for $8. Had a mate run a bead of weld around one end and then grind back for a stopper, and then drill and tap a hole at the other end for the retaining nut/screw thingie.

I can now balance my 10" reflector on the eq6 with just the 2 standard weights rather than 3.

The point being, if you have a little know how and the right equipment or know someone that does, you can save a lot of $$$.

cheers

Mark

[peter_4059]

How secure is the joint between the two bars Mark? I imagine there is a fair bit of stress on the threaded connection with 10kg of weight hanging off the end of the bar.

[Marko of Oz]

No joint Peter. I've totally replaced the original shaft with the new one.

[OneOfOne]

I extended my CGE bar by simply turning down a length of aluminium round bar (about 100mm long) to the same diameter as the counterweight bar. The screw into the base of the bar is a standard thread, 3/8 or something like that, so I just picked up a bolt from the local hardware store and cut the threaded section off. Tapped a whole in the centre of the extension and screwed them together. The old locking screw just goes into the end of the extension....all up cost was about $10.

Prior to this, the weight had to right at the end of the bar but after I put some other bits on the tube it was too heavy to balance any more.

[Chippy]

I want to get this for my HEQ5Pro. Sounds simple but unfortunately I don't have the tools for turning down or tapping, etc. Several posts on this have mentioned getting a machine shop to do it. Maybe I should just look in the yellow pages, but does anyone have a suggestion of where I could get it done (cheaply)?

[JD2439975]

Nice & cheap, rough n' ready.

Bit of steel pipe, weld a bolt on the end, couple of bucks for weights at the tip shop, maybe some paint...BEAUTIFUL!! :thumbsup:

9 kilo's not going to break a full weld under low g's.
Crude but effective.

[rider]

I bought a nice second-hand aluminium extension on this site.

It's held on by a couple of Allen key ended grub screws. Its very secure.

There is an overseas site that sells them, but I can't remember which one.

I was originally going to build a longer one piece shaft, but the separate extension has turn out to be great, because when you travel you can take all the weights off just by removing the extension and they don't bang around in the back of the car when they are all still on the shaft.

Rider

[peter_4059]

Plenty of alternatives there but has anyone done the astro-rubylith mod? It replaces the shaft with a much heavier and longer one.

[mldee]

Which site, I think you may have forgotten the url.

[peter_4059]

I think he means "this" site

[The Mekon]

Just taken delivery of my EQ6 pro (thanks Benno85)
Its raining so I have to play with it.
The counterweight shaft is pathetic. Only 18mm - the SPDX it is replacing has a 20mm shaft. Took the shaft out. Seems a 20mm shaft will fit if you can guarantee the clamping, the shaft is reduced to 18mm so the 20mm collar on the end retains the shaft from falling out.

I reckon I may give up the ability to slide the shaft back into the housing and build up a 22mm shaft. Means boring out the bottom dec cap by 4mm (and the weights) - straight forward

First up I will see how well the mount works - there was not much grease on the roller bearing I pulled out of the dec housing, so a strip down might come sooner rather than later.

[TrevorW]

New collar and 25 mm stainless steel shaft that way you can shorten the shaft length

[Tandum]

Ohh, this is an old thread. http://www.kendauzat.net/other/1005041b.jpg

I had something similar made at a machine shop here. I sold it to rider after I sold my eq5.

[asimov]

Wouldn't you blokes be better off just banging another weight on rather than shaft extensions? The weights are better off being as close to the centre of gravity as possible. I've added an EQ5 weight to the mix on mine, with a spacer. The EQ6 shaft is smaller than the EQ5.

I guess it's cheaper to extend than buy a new weight I guess - I'll shutup now..:)

[Barrykgerdes]

A source of additional weights is the sports section of Target/Kmart etc.
I can bore them out or make sleeves for any size shafts and add locking screws.
Another source (not so pretty) is the local steel store for offcuts of steel shafting. These can also be bored to fit any size shaft.

Always remember however that a commercial mount will normally be supplied with a weight to handle its maximum design load.

Barry

[bmitchell82]

I know how to do the modification it is very simple indeed to do and takes about 5 minutes to install.

Yes i do have all the gear to do the job too.

If anybody needs more advice just give a hoy.

Brendan

[robz]

Received the latest version of the EQ6 PRO yesterday.

It has a new model number/prefix or something like that(will have to check the box) , and behold!.................an extension shaft and larger dovetail head have been included amongst the accessories:thumbsup:

This will mean that SW will have this extension shaft as a spare part/accessory listed soon enough if not already:question:

[The Mekon]

My gripe is not with the length of the shaft, but its diameter and the way it is only supported by the collar, and hence the fine aluminium thread that holds the collar to the steel shaft. Imagine the dec axis horizontal. For those using 3 cwts, the stress on this joint is large. The shaft should extend up into the hollow of the steel shaft to be supported correctly. Sure it may not be retractable then, but at least will be engineered properly.
Today I commissioned a 24/20mm stainless shaft that will be properly engineered. The collar will be bored to 24mm. I'll post pics when I get it.

[The Mekon]

OK, here is the new counterweight shaft. Started out as 400mm x 25mm of 316 stainless
Machined to 20mm diameter for 80mm, then 25mm for 2mm, then 23.8mm.

Counterweights bored to 24mm. ( beware this will expose the horrible casting flaws in these weights!)

Declination collar bored to 24mm, - problem with China manufacture, hole not concentric with fine threaded section of the collar.
Solution was to machine the shaft down a fraction of a mm in way of the collar only.

Now the force of the balance weights is properly taken up by the steel declination shaft and not on the fine threads of the aluminium collar.

Shaft can be made any length you wish.

A lot cheaper than the Altair Astro option from the UK

[peter_4059]

Nice solution John. How much does the 400 mm SS rod cost and where do you get it?

[TrevorW]

Buy 316 SS not 330 like I did, which is near on impossible to cut on a home lathe unless you have a big one

[The Mekon]

Hard to say the exact cost of the shaft. I had it made up along with some other modifications to my tension leg pier.

I can say that stainless 316 bar of 25mm diameter is around $80 per metre, and weighs 3.9kg per metre. Your local steel supplier should be able to get it in for you.

[The Mekon]

Attached is the pier adaptor made to fit the EQ6 to my tension leg pier.