Turning EQ5 mount into Alt Az in half an hour!

[mental4astro (Alexander)]

Hi all,

A recent conversation with Morton had me look more closely at my EQ5 mount. I had looked at the possibility of turning it into an Alt Az mount a while ago, and it looked very promising, but until now I didn't take it any further.

So, this morning, with access to every single tool, both electric and hand powered, I looked at completing the task. As it turns out, it is so bloody easy!

EQ5 mounts that are suitable:
If your mount only has slow mo controls, that is fine! If your mount has dumb RA and Dec drives, this is fine too. Where it is not well suited is if your EQ5 has a goto function as this mod may not work with the electronics of the goto as the mount will be in an Alt Az mode.

What you will need:
You will need two tools, an allan key and a file, and one other thing, a 1/4" full hex nut.

Proceedure;

The whole process take all of half an hour, and it will not alter the equatorial function of the mount.

1, Remove the front altitude plate on the mount and the alt bolt on the rear of the mount.

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2, File down the flange that was behind the plate - this flange stops the lug that the alt screws push against from swinging through past approx 60°. Space is tight here, and it is this filing that will take up most of your time. The metal is soft aluminium, so it won't take too long.

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3, File down the two stops on the rear of the mount. These two stops prohibit the mount from swinging past approx 75°.

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4, The Nut Once the filing has been done, the mount head can actually swing through past 90°. So to set the mount to the correct tilt, place a 1/4" full hex nut in the slot where the two rear stops were. In case you did not know, nuts come in full thickness hex, half thickness hex, & as square locking nuts. You need to use a 1/4" FULL hex nut here as the others are too thin.



5, We have life! Tilt the head back with the full hex nut in place, and the mod is complete!



Restoring the mount back to equatorial mode.
To revert the mount back to equatorial mode, tilt the head forward and replace the front plate and the rear bolt to the altitude hinge and manipulate the adjustment bolts as needed to restore the required tilt of the RA axis.

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continued in next post...

[mental4astro (Alexander)]

Proof of concept

Here is my ED80 coupled to the mount with a 5kg counterweight. Both clamps here are totally loose and the OTA is balanced in the alt axis.



EASY!

If your mount has dumb RA & Dec drives, this mod does not affect their use, and you can use the drives to move the scope effortlessly too. Just remember that you will need to move both drives in this alt az mode. If you want to use the slow mo controls instead of the drives, just undo the clutches on both axis. Very easy

EDIT: It just occurred to me that the RA drive will always be on so always tracking, unless your drive system has a way to disable it.

Alex.

[JimsShed (Jim)]

Great instructions and a useful project. Also thumbs up for finishing off with a nice paint job

[mental4astro (Alexander)]

Thanks Jim

Tip for filing aluminium

Aluminium has a nasty habit of clogging up the teeth of files, and all other cutting implements such as drill bits and countersink cutters. This is really nasty stuff as it can be impossible to clean the file even with a wire brush.

The easiest way to help stop this is with a BAR OF SOAP!

You rub the bar of soap all over the file, and start filing away. After a short time you can clean the file as normal with a wire brush, reapply the soap and keep filing.

Brass and copper can also clog up files, and the soap trick will save your tools.

You can also use this soap trick with drill bits, countersink cutters and hacksaw blades.

Alex.

[iborg (Philip)]

Hi All
Alex's idea with the soap may be the best bet, but, there are also file cleaning brushes which do a much better job than your average wire brush.


See link if curious
https://www.ebay.com.au/itm/File-Cle...frcectupt=true


Philip

[alval (Alan)]

Thanks Alex another project on the to do list. The list is certainly not getting any shorter.

As for working with aluminium Ive done a bit. Drilling or hacksawing etc. something like wd40 works well. Filing just use chalk, load up file, a few strokes, a tap on the bench most falls out, bit more chalk and so on. Eventually a wire brush, and for those stubborn bits a piece of scrap brass to push the bits out. It will keep your files like new.
Al

[netwolf]

Alex did the same a while back with intent to make a alt az goto setup, but ran into issues with skywatcher goto system not supporting alt az mode. The mount works fine as a manual alt az though.

[mental4astro (Alexander)]

Thanks for the additional tips in working with aluminium

Fahim, I suspected that the Skywatcher goto system might struggle with being put into an alt-az mode. Thanks for confirming that.

I had a brief session with the newly modded EQ5 the other day. Used the same set up as in the pic below of the ED80. Slow mo action very smooth and effortless. With the tilted-back head of the mount set over on of the tripod legs I found no discernible issue of flex or unsteadiness. Mind you an ED80 will hardly bother an EQ5. There is a certain reassurance that comes with having some bulk and muscle in an alt-az mount that makes lighter mount feel rather flimsy.

Alex.