EQ platform

[iceman]

Hi guys.

Brian, a guy from the US who just joined up here, I met through the CN forums. He's an ATM'er, and makes EQ platforms for sale.

I'm considering getting one myself, and got his permission to post the details here incase anyone else is interested.



Prices:


Here's a few pics, the black one was ordered for an 8" orion.

[iceman]

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[iceman]

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[Orion]

How big does he go with his platforms? And is that in US dollars?

[MintSauce]

hang about - they are not for photography? so you'd spend that much just to get tracking so you don't have to nudge the scope? (not trying to sound rude - I just would not spend that much for convinience)

G.

[Starkler]

Does he have a website for these ?

Theres a few questions I would want answered if I was going to buy one.

1: how big is it?

2: Height of the axis of rotation wrt the centre of the top board. It is important for stability reasons that the dobs centre of gravity is below the axis of rotation. This will vary according to designed latitude.

3: How long will it track before requiring a reset?

4: How do you reset it?

5: Motor step size in arcseconds rotation of the top board.
This is important. If there is not enough gear reduction, discrete steps of the stepping motor may be visible at the eyepiece when observing at high power.

[Starkler]

It may be worthwhile for a dedicated planetary observer who doesnt want to miss an instant of good seeing that could be missed while nudging the scope. It also makes it easy to show other people without having objects move out of view, public nights etc.

Short exposure photography (webcam) shouldnt be a problem.

[iceman]

The prices are in $US.

They wouldn't be suitable for long long exposures of DSO's, however they would most certainly be able to be used for webcam + short exposure DSO photography.

When he says "It cannot be used for guided photography", guided is the key word there. So you can't change it's tracking on the fly to match a guide star.

Geoff, no website, he's only just started offering them up for sale.

With regards to your other questions, good questions, i'll get him to answer himself, as he has signed up as a member already.

[Brian]

Thank you everyone for your interest.

I believe a tracking platform should not cost as much as a good new scope.
The platforms shown are an affordable solution for the small and medium size Dob users who just want the convenience of not nudging their scope all night to keep an object in view. Tracking is great for planets, but I also like it for deep sky observing. It keeps deep sky objects centered in the field of view where my eyepieces perform best.

It can easily handle up to a 14-inch scope. For a 15 or 16 inch, I would need to make the platform slightly larger and add an extra bearing support for stability. This would depend on the weight and rocker box size of the individual scope (a slight extra charge depending on size needed). I charge $20 more for a solid paint color because of the extra sealing and sanding involved.

The platforms shown are 5 ¼ inches tall including the pads, 23 inches diameter, weigh 17lb, and tracks for 50 minutes. The motor steps at .55 per arc sec. and has a 300:1 gear ratio, which gives it plenty of torque to handle the 19-inch center of gravity. It uses manual reset by simply lifting the corner of the platform and sliding the table over. The scope can be set on top of the platform or directly attached replacing the ground board.


Thanks,
Brian

[iceman]

Brian, Thanks for your responses.

Does it need to be setup on level ground? If so, what would be the impact if the ground is not exactly level?

Is it adjustable for latitude at all, or is it set in concrete once ordered?

Does the bottom board have feet on it? Just thinking about it resting on dewed up grass etc.

Anyone know how much customs + GST would be on this? Even at the cheapest shipping option (seafare), it's AU$525, over the AU$500 limit for customs.

Thanks

[Starkler]

The hard part is constructing the bearing supports, the circle sectors and sourcing the stepper motor and electronics.
Perhaps a kit option with all the bits (supply your own ground and top boards) could save enough to make it customs friendly ?

Mike for visual use, perfect leveling and polar alignment doesnt matter. When I use the eq mount for the ED80, I just plonk it down and make a rough guess and its good enough. It just means an occasional tweak on the declination is required.

[ving]

looks really sound brian :)

welcome to the forum :)

[rmcpb]

The kit option sounds like a great idea but only if you can really mark out and connect the bits to the top and bottom board accurately or you will get the wobbles.

And we all know there is nothing worse than a wobbly scope :)

[Brian]

The leveling pads fully extended allow for plus or minus 5 degree latitude adjustment or about 700 miles total. I use a bubble level and a compass to set up the platform on my own scope. It takes only a few seconds. There is a precise alignment procedure using a cross hair eyepiece that can adjust for latitude and polar alignment, but it's not really necessary.

Sorry, but selling kits is not really what I had in mind when I started selling these.

Thanks,
Brian

[iceman]

Thanks for the info Brian.

[rmcpb]

I think Brian is on the right track. My earlier comment was in regard to the latest upgrades to my platform to get rid of the little wobbles, its harder than you would think. If he started to sell the little bits he would end up having heaps of problems with customers who didn't put it together properly and then blame him, a really sticky situation.

To be fair to him you would have to buy the completed item he has tested or make your own.

[ving]

like that glue manufacturer....


why the hell would you want to build it yourself anyhow when there are people that will do it for you! :D