I think I mentioned that I don't have a mount, so it is difficult to measure real-life situations. The purpose of my test was to determine whether there was a potential problem with flexure. I wasn't

Andrew, The older QMD mounts in my experience run about 8 arc seconds peak to peak. Improvement in this has a lot to do with balance. I've seen 4 arc seconds peak to peak with my QMD, but only after

Robin, Have you checked the flexure in compression with a simulation of the load imparted by the OTA? I think that this will be different than the flexure that you see when you lift the DOVELM. The

Hi Robin, From looking at your photo, it appears that the 17.25" dovetail bar is too short and could cover more of the forward and aft mounting points. If you are making new plates, make them

Robin, It's hard to believe that your instrument alone can cause this much movement in the plate. I'm particularly interested, as I have a new larger optical tube being mounted in a similar way. I

Why not? No place else for it to come from than the bar. If the test is done without the DOVELM, the dial indicator shows a change of more than 0.007". The DOVELM stiffens the system. As others have

Robin, A couple of things. Changing the aluminum alloy will have virtually NO effect on what you care about- stiffness. All aluminum alloys have (for practical purposes) the same material stiffness

Robin, I don't think replacing the Losmandy plate will do anything. I also don't think that the flexure is coming from either the Losmandy plate member or the DOVELM. I'm sure you've inspected all of

Chris, Have you checked the slew rate of the telescope set in DSV? It maybe moving and you don't notice it because the slew rate is very slow. On some mounts the slew rate must be changed from the

Well, I wasn't going to bore everyone with the details, but since a couple people have made recommendations regarding the plate, here goes: I have a 600EGTO but it isn't heavy enough for the 10" Mak.

So, am I understanding correctly that you suggest: 1. Forgetting about the expensive 7075 and going with 6061? My cousin is a machinist, not an engineer. He didn't recommend one over the other, but

Hmmm. I was close. I thought it stood for Quartz Motor Drives. Andy

Thanks for the help Bert, I doubt I will ever, ever use goto systems. But I wish to know how good these past AP-1200 can track. That is not on the website. I already understand the drives of the

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Quartz Micro-Drive. Gus

Hi Andy: You definitely want to go to the A-P website (www.astro-physics.com) for the quantitative numbers, but here are some impressions (I'm just in the process of installing a 1200GTO now). The

Not sure if this is the place for this post or not. I just got in from using DSV 2.02(latest upgrade). I calibrate my 900GTO with the keypad, then switch to the keyboard and establish link. All

Andy, I think you'll find all the info you need on AP's web site. http://www.astro-physics.com/ Steve SedlacekAndrew@... wrote:

In my research for another mount for my FCT-150 system, I ran across the AP-1200. And I really like what I read about it! Especially since it can harbor twice the weight of the EM-500. But I have

The stiffness of the beam will be a function of the cube of the thickness multiplied by the modulus of the material. When you consider that increasing the thickness by a factor of 5% yields