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EzCBP Equatorial Platform - It Really IS Easy!

Started by Charlie Hein , Aug 24 2013 04:20 PM
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14 replies to this topic

#1 Charlie Hein

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Posted 24 August 2013 - 04:20 PM

EzCBP Equatorial Platform - It Really IS Easy!

By Michael Coren

#2 george golitzin

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Posted 25 August 2013 - 05:37 PM

Nice review, and a nice build of the platform. However, I would suggest, Michael, that you test the platform on some night when the seeing will allow 300X. I found that my ExCBP contributed too much vibration to the image to be usable at that power--a fact that I could only see by turning the drive on and off repeatedly while observing Saturn in my 8-inch on a night of very good seeing. It was handy, however, for star parties and such, but I finally sold it.

-george

#3 Deep13

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Posted 26 August 2013 - 10:11 PM

This thing was a royal pain to assemble. The instructions were vague with regard to measurements. The vendor was useless and a bit derisive in response to my questions. What made it worse was that the measurements were in 10ths of inches, not metric and not fractional inches like nearly all rulers in this country. When I finally got it put together, I could not get it to run due to friction in the system. The supplied bearing were too flimsy and the motor too weak to drive the system. Also, the drive wheel did not make a good connection with the RA bearing due to being undersized. Yes, I assembled the electronics properly. I eventually gave up on it and went with a Roundtable model, which failed after a pretty short time too.

#4 mcoren

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Posted 27 August 2013 - 09:23 PM

Thanks George. I'll definitely have to give it a try at 300x on a night of good seeing. Hopefully there will be some cool fall nights with steady air.

#5 mcoren

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Posted 27 August 2013 - 09:31 PM

Deep13, I'm sorry to hear you had such a tough time with it. My experience was much different than yours, obviously. I don't know when you bought your kit but I got mine in July of this year so maybe the parts and/or the plans were updated in the interim?

I agree with you about the 1/10 inch measurements, and I mentioned that in the article. When I was in college I took a drafting course and had to buy an engineering scale that was graduated in 1/10 inch, but other than that just about every ruler and tape measure I've seen in the US is in 1/8, 1/16, 1/32, etc. I wouldn't bet on the US going metric anytime soon.

#6 kfiscus

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Posted 27 August 2013 - 10:10 PM

So you're 0 for 2 with EQ platforms?!? I've had only good luck with my two, one a lightly-used Atomic and one a brand new Round Table (when they were still being built). Hope your luck with astro gear turns around.

#7 csrlice12

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Posted 28 August 2013 - 11:43 AM

Have the kit, bought it a couple of years ago, got the wood, cut the curved board.....and it's still setting in the box in the garage.....the instructions are not very clear, although Ted was helpful in making computations. It's not the kit, I'm just not a handyman/woodworker....I know a guy who is though, wonder what he'd charge to finish the project???? I'd want to go to a furniture store to have the curved board cut though. The curvature of that board will have a lot to do with how smooth it operates. A good CNC mill could cut that curved board in seconds.

#8 gmartin02

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Posted 31 August 2013 - 01:06 AM

A very accurate radius for the curved board could be very easily cut with a hand router and a large circle guide - just like making Dob altitude bearings. No need for a CNC mill. For more stability, I think you could replace the curved board hinge connections & latitude adjuster with triangle reinforcing boards and just make the platform for a fixed latitude.

#9 mcoren

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Posted 31 August 2013 - 09:42 AM

Personally I didn't have any trouble using the method in the EzCBP plans for cutting and smoothing the curved bearing, but I had a few scraps around from other projects that I was able to use to build the jig.

Another option: A few years ago I was working on a 6" dob with my kids and we needed two circles for the altitude bearings. I knew I wouldn't be able to cut two circles myself of good roundness and matching diameter, so I asked a colleague who I knew did a lot of wood work to help out. The next day he gave me two perfect matching circles cut on his band saw.

#10 azure1961p

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Posted 31 August 2013 - 02:12 PM

Nice review, and a nice build of the platform. However, I would suggest, Michael, that you test the platform on some night when the seeing will allow 300X. I found that my ExCBP contributed too much vibration to the image to be usable at that power--a fact that I could only see by turning the drive on and off repeatedly while observing Saturn in my 8-inch on a night of very good seeing. It was handy, however, for star parties and such, but I finally sold it.

-george


I've read sometimes the vibration is one motor working too hard due to balance or whatever. A second motor in tandem appears to iron out these things.

Pete

#11 dupouy

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Posted 09 September 2013 - 09:04 AM

Making the Ezcpb, I had to make some improvments :
1) put two switches to stop the motor at each end of course backward and forward.
2) add two leds (red and green) on the control box as indicators for forward/reverse.
3) put triangle 45° for fixed latitude and so reinforcing the panels.
Inconvenient: no system to restore the sector at end of tracking. you have to lift up the upper table to put it back to the beginning. Tedious when you have the scope on it. I have to think abpout putting a lever mechanism to do that.
If the motor fail, Ted can supply n another one, but the price for it, is 95$ !!
I had to change one of the switches wich was bad.
Roger

#12 George Methvin

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Posted 07 November 2013 - 02:05 PM

WOW I am pretty happy with mine built it in a weekend. I was not real sure about some of the measurement so I just kind of guessed as close as I could. My platform is not a work of art and my cuts were not alway right on beleave me. In fact I can tell you my 27in radius is not all that smooth of cut or accurate. In fact the whole thing is kind of rough looking but it works and a lot better than I would have thought it would with my building it. I only use a compass to point the platform to north and do a rough level and I find that object stay in a 11mm eyepeice for up to 5 mins or more and in a 32mm eyepeice up to 20 mins or longer and thats way long enouch for my viewing. I am not even sure I have my platfrom set to the right lat. :lol: but its sure beats the heck out of having to push and pull the dob every 30 sec to keep a object centered. It is so nice to be viewing M-13 and go in and get a cup of coffee and come back to the eyepeice and have M-13 still close to the center of the field of view in the eyepeice. Over all very pleased by the way it turned out, is it perfect no but good enouch for me. Sorry about others having problems with theirs. Clear skys

#13 Bob Riggs

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Posted 23 November 2013 - 07:15 AM

Very nice article, Michael. Thank you!

I'm likely to go for a dual-axis kit pretty soon. Your experience is very encouraging for me.

Clear skies...Bob

#14 Trevor Durity

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Posted 10 February 2014 - 02:02 PM

Great review Michael. I've had one of these kits sitting in a box for a couple of years waiting for me to set aside some time. Time to dig it out and start woodworking :)

Trev

#15 Jeff2011

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Posted 11 February 2014 - 11:36 PM

Nicely done. I decided to build my own. A blend of various examples I found on the web. I went with a tangent drive instead of the direct drive method. Was not easy but was a fun project. If you have a table saw (which I fortunately did), it is easy to cut a circle. After seeing this video, I knew I could do the project. Warning, you will have to see a short commercial before you get to the good stuff.

http://www.videojug....n-a-table-saw-2

I used this technique for cutting the top and bottom boards and the sectors.

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