Equatorial Platform for Dobsonian Telescopes

[SniffTheGlove]

well it certainly tracks. I reckon though that I only get maybe 10 minutes at 250x before it drifts out of view. still a lot better than previously. I'll report back again later when the moon's up (here - behind houses currently).

It could be a few things Shane...

Not directly polar aligned

Need to reduce pwm slightly

Platform not correctly level

PS, How have you connected the motors to the platform?

[Moonshane]

cheers Sean

I'll be checking everything out. I'll upload some pics later showing the various connections etc.

[Moonshane]

in fact here's some just taken at half time of the footy (City V Chelsea) showing how it all fits together.

the connection to the motor shaft is a little grub screw and the centre of the bolt is drilled out to about 15mm depth.

hope this is self explanatory but ask away of not.

[Moonshane]

last one with the covers in situ. might paint these white.

[SniffTheGlove]

Here is a reasonable alignment guide (bottom of page) My equatorial platform

Is that M12 threaded rod and connector nuts.

This is what I did but my threaded rod is up a lot closer now to the top of the platform as I found that when the weight is on my rod to platform attachment strip would apply force sidewards to the threaded rod which in turn applies friction to the rod.

I am going to have one more go tonight then with my puny stepper else it will be off to order a motorgearbox that will have more torgue.

Thanks for the photo's Shane.

[Moonshane]

hi mate

thanks for the link - looks very useful, I'll give it a try next time out. my problem will be that it takes an hour to get to my end positions (although I could manually turn the rod).

In fact I am considering removing the reverse motor as I could do this by hand quicker I think with a little winder.

the rod/bolt/connector are M10. if you used M12, you might be able to file a flat and put a grub screw there or epoxy a nut on the end (why didn't I do this?? ) . this would remove the need for the bolts. In fact I may well do this in the future.

[ponytale]

PM'd Sean

[spaceboy]

Could try some heat shrink on the cabling Shane. Would offer protection and make a neat job of it.

[GazOC]

hi mate

thanks for the link - looks very useful, I'll give it a try next time out. my problem will be that it takes an hour to get to my end positions (although I could manually turn the rod).

In fact I am considering removing the reverse motor as I could do this by hand quicker I think with a little winder.

the rod/bolt/connector are M10. if you used M12, you might be able to file a flat and put a grub screw there or epoxy a nut on the end (why didn't I do this?? ) . this would remove the need for the bolts. In fact I may well do this in the future.

At the end of the tracking run mine has a bar to disengage the motor from the tracking plate by lifting it up and the platform and scope is just pulled back to the starting position.

[Moonshane]

cheers Gaz

this is another way to do it and I may do it in the future if I make another one.

for now it takes less than a minute to wind back by hand (I have took off the reverse motor as it was very noisy) and I am working on a method to do this. I'll add further pics as I go. I think that like a scope, an EQP can be adapted to suit needs as you go.

[SniffTheGlove]

Shane, finally had enough with my stepper motor setup and I am going your way, I have found the same controller and motor as you have on eBay.

[Moonshane]

nice one Sean, I bet you'll find it easier.

I have just made some final (yeah right) mods to mine and have nicked your idea for end supports for the drive rod. there's a skate bearing glued into the hole and I used an M10 - M8 reducer to connect an m8 bolt through it all.

I also found there was too much slack in the connecting nut and bar and there was a fair amount of lateral movement. therefore I used two connecting rod nuts instead and also a brace to tighten everything up. It's a bit 'frankenstein' at the minute as I learned as I went so I may replace this in due course now I know what it needs. works OK though. it's a manual rewind at the end of the run but takes (literally) a minute to do.

it's all now wired up, tidied up and working so just need some clear skies (and a lick of paint on the cover and end bracket to match.

here's some (bad) pics of the latest mods and also one of my 6" f11 planetary scope for which this was really made (although my 12" f5.3 sits on it well too.

hope yours works out too.

I reckon having done this I could replicate it much more rapidly as 1) I know what to do and 2) I know which parts works and which don't.

[Bigdaddyjeff]

mine looks a lil like that......no the fence in the background i mean ....cracking build and design m8....excellontay!!!

Gaz

[Moonshane]

cheers Gaz. I can see my flags need jet washing!

[Bigdaddyjeff]

not as much as mine need weeding

[spaceboy]

Finishing post not far of now then Shane you must be excited to give it a try out under dark skies. I have got mine all done now and will be sorting out corrosion resistance by hot dip or brush dip depending on cost. The Nag zoom is now my most prized possession for use in all my scopes thanks to your inspiration for a EQP

SPACEBOY

[SniffTheGlove]

Hi Shane, how has it all gone in the end and did you get it working ready for SGL6. What's the latest?

[Moonshane]

hi Sean

It's actually working really well. I am really chuffed with it. I find that it works superbly at my normal mags of 150-250x and only drifts slowly even at 500x.

there's a (resolvable) issue with the threaded rod/ bolts as I don't think something along the line is centralised (I suspect one of the bolts was not machined perfectly). I think I can use a piece of 2mm ali bar instead of the 3mm currently in place and this show flex enough so that it's not transferred to the eyepiece. All it means is that every revolution approx, the image shifts a little back and forth but it's something I can live with for now. working on solutions in my head though.

did you spot Nick's thread http://stargazerslounge.com/diy-astronomer/134113-eq-platform-help.html he's done a truly superb job and something to emulate for sure.

I took mine to SGL6 but only ended up staying one night for various reasons so didn't really bother with the EQP.

[SniffTheGlove]

That's really good news Shane and also well done to Spaceboy, doing it in metalwork does make a stronger platform.

I am glad you can get good steady mag, now to see some webcam images soon then :-)

[George!]

How much was the total cost?

[Moonshane]

it was around £100 max but you could probably do it for a little less.

[George!]

Very cheeky question, but would you ever think about making and selling? Hate to ask this but there's always an answer.

[Moonshane]

not cheeky at all George. to be honest, it's the time that would be the issue for me. I work full time and when I can I observe and when I cannot I have a family. so unfortunately I really cannot offer this service.

[George!]

Thanks for your kind response.

Also, if the store have this in stock when they reply, do you think I should snap at it with extra funds and sell my current? ( Very Good Condition )

Then again an extra £375 is hard to find, and it's like buying a commercial EQ platform.

Skywatcher Skyliner 250PX Flex Tube Auto Tracking Telescope, UK, WC1

[Moonshane]

personally I'd buy a commercial equatorial platform if that's the difference as that would not cost much more and you could use it with any scope. there is an advantage with the flextubes that they are a little more portable but not much to be honest.

it's a tricky decision.