DSV-3 First Impressions

I received my DSV-3 alt-az mount from Desert Sky Astro a couple of days ago. The weather here has been terrible so all I have done so far is play with it indoors for an hour or so. The mount was very well packed, and arrived without issues. Nothing was loose or missing.

I am using it on a Stellarvue heavy duty surveyor's tripod with a 5/8-11 mounting bolt. The mount attached solidly to the top plate and the whole assembly seems very sturdy. I am using the mount primarily with an EON 120 refractor, 900 mm FL and about 15 lbs. loaded up. I plan to add an AT72 refractor or a C8 SCT to the other side occasionally.

I did a quick set up of the QBS balancing system with my range of eyepieces from an ES 14 mm 100 deg to an ES 34mm 68 deg to an WO 4 mm UWAN. The setup was pretty straight forward. I need to spend more time with it since the largest eyepieces were slightly out of balance when pointing the scope vertically. The mount can also be used without the QBS, you just need to balance the tube back and forth as usual. I found that to change eyepieces without having the mount move in altitude requires you lock down the altitude lock pretty tight.

When the scope is balanced, moving it in both axes is very smooth either by pushing on the scope or using the panning handle. The slow motion controls work with a clutch mechanism so there is no lock to engage when you switch from panning to using the slow motion controls. I adjusted the axial tension slightly on the altitude control because the tension when turning the knob was a little more than I liked. When the scope is balanced there is no stutter in the altitude axis.

This is a very solid mount that I think has been well thought out. The proof of course, will be how it works under the stars. But from the look and feel of it I think it will be a keeper for me. Also, Raul has been great to work with. He has patiently and promptly answered all my questions. When I can get it outside, I'll write up my thoughts about how it performs.

Congrats Kevin, Long wait, but finally is over

How long did you wait for delivery Kevin?

I ordered it in mid December, so about six weeks to get it to my front door.

Any updates? Photos?

I have only had one chance to use the outside since I received it, that was for about an hour from my driveway during a break in the clouds last week. I used my EON 120 and the object of interest was Jupiter, which is pretty high up in the evenings now. I had worked with the QBS inside the house and gotten the scope balanced for my range of eyepieces. under the stars

I found the mount to be solid with very little or no vibration when focusing or tracking with the slow motion controls. Panning when using the finder was very smooth. There is a handle included with the mount, but I panned by pushing on the scope. I had adjusted the tension on both axes so that there is just a tiny bit of play when changing direction in the az axis and none in the alt axis. The tension is adjusted by turning a knob at the end of the work gear and then locking the knob in place with the set screw. The slow motion knobs are positioned so i can reach them easily and I found that after a while, I was putting my fingers right on them when reaching for them.

There is no stutter in the alt axis. The pier is tall enough and the arms are long enough so that there was no issue with the scope bumping into the tripod when turning on the az axis. The mount has stops on the alt axis the prevent the scope from going much below horizontal or much beyond vertical.

The QBS works as advertised, although you need to be careful to engage the alt axis lock when changing eyepieces or else the scope will take a nose dive. All my eyepieces balanced without needing to engage the alt clutch, except my ES 14mm 100 deg. When near vertical I need to engage the clutch for that eyepiece. Raul says I may need to add another weight to the QBS (the DSV-3 comes with two weights). Leveling the mount is important for the QBS to work at its best. There is a bubble supplied on the top of the mount.

I tried the mount without the QBS and had no real problems, I needed to slide the scope back and forth to balance it when changing eyepieces and need to engage the alt clutch when most eyepieces were pointing near vertical.

Overall I am very satisfied with the mount. I really want to get it out more and get to where it fades into the background and its use becomes second nature. I'm sure that will come with time.

Likes
- Very solid, well thought out design and attention to detail in the build.
- Slow motion controls are precise with no backlash, the knobs are large and easy to grip.
- Lockless panning is very smooth
- There are stops on the altitude axis to keep the scope from going much below horizontal and much past vertical.
-Plenty of clearance provided by the column. My scope does not come close to the tripod legs.
- Axial adjustment of the worm gear is very simple, if you need to adjust the slow-motion tension.
- Hardly any vibration when tracking with the slow-motion or focusing.

Dislikes
- None

Annoyances
- You need to remember to lock the alt axis when changing eyepieces. This is more of a learned process.
- Setting up the QBS can be tricky, you need to carefully balance the scope and make sure the mount is level.

The attached photo shows the scope balanced near vertical with an ES 14mm 100 deg eyepiece.

This photo shows a close up of the front of the mount. The large knobs are the alt and az slow motion controls. The ones at the angles are the dovetail shoe locks. The one on the opt right is the alt axis lock. The bubble level is above the nameplate. The alt axis clutch is to the right of the nameplate. Very clean lines.

This one shows the back of the mount. The small knobs are the radial adjustments for the worm gears. The horizontal levers near the base is the az axis clutch. The vertical lever is for the alt clutch. The two bolts next to the alt clutch hold the mounting for the optional DSC encoders.

BTW, the mount sits on a Stellarvue heavy duty surveyors tripod with a 5/8-ll mounting bolt. I have the legs extended a little less than half way.

This one shows the scope balanced with an ES 4.7 mm 82 deg. eyepiece. The finder is an Orion 9x50 RACI, and the diagonal is a TMB quartz 2". Notice the counterweight on the QBS is in the lower position. The little white spots are supplied with the mount along with the velcro strip they attach to. Each one is placed where the counterweight needs to be placed along its track to balance the eyepieces.

On last shot showing the scope, mount and tripod.

Very nice update and cool pics. I'm even more eager for mine now.

Thank you Kevin for the informative description with the pics!!! I have been waiting for a field report of this mount. The only thing you don't mention is what magnification you could use on Jupiter and still track it well and how the vibrations were if any? 200x+ ? In addition, do you find the off center weight hanging off one side (typical T mount configuration) to be an issue or do you find the eyepiece balance weights enough to offset this so that the setup is not tippy? They are sure alot lighter than the usual 10# counter weight necessary! Lastly, my scope will push 21# at 840mm...still doable in your opinion?

Great review Kevin, you have a terrific looking kit there Do you know if Raul has a slo-mo cable option available? I'm not a towering giant and it looks like I would have to lean in rather uncomfortably from behind my TEC 140 to work the controls. Thanks!

Clear Skies,
Brian

I used the mount again last night from the spot in my backyard where I took the pics. The tripod was resting on top of a layer of frozen snow. My 4.7 mm eyepiece gives 191x which was too much on Jupiter for the conditions last night. I did use it for awhile and did notice a little vibration when using the slow motion controls, but not enough to bother me and it stopped as soon as I quit turning the knob. I had no issues tracking at this power though. I spent most of the time using an 11 mm, 2x Barlowed which is 163x. At this power there wasn't any noticeable vibration. I accidently hit the aluminum tripod leg with my elbow and it took about 5 seconds for this to settle out. I attribute this to the tripod sitting on the frozen snow and ground and not the mount.

I have never had any concern of the setup tipping over, it is very stable in that regard. The QBS is fairly heavy, but even without it attached, I didn't notice any tendency to tip.

My scope weighs a bit under 18 lbs with the 11 mm eyepiece and Barlow that I used last night. It has a 900 mm FL and is 950 mm tip to tail with the dew shield extended. Depending on the tripod you will use I think your scope is doable IMHO. Raul at Desert Sky Astro could tell you for sure.

My suspicion about the vibration you're experiencing using the slo-mo is due to the fact that the knobs are so short (of course, as knobs should be). If Raul does sell long slo-mo controls I would expect your issue with vibration to be greatly reduced, if not eliminated.

Goodchild:
The vibration at 191x was not enough to bother me and I probably wouldn't have payed any attention to it if I wasn't looking for it. I have a longer knob I picked up from focusknobs.com a while ago. It's five or six inches long. If it fits on the shaft, I'll give it a try some time.

Brian:
As far as slow motion cables go I don't know if Raul sells any. I think Agena sells some and they may work. I am 5'10 and the knobs are in easy reach for me when seated, but I'm sure your scope is longer than mine.

It appears as though the QBS occupies 1/2 of the mount. Is there any way to use a second scope along with the QBS or is it an "either or"?

-Dan

Two scopes and QBS can be rigged...

http://www.desertsky....com/DSV-3.html

Understand the QBS can be attached to scope rings. Not sure what the method of attachment is. My SV110ED has 6mm metric holes in the rings instead of the normal 1/4", so I might have an issue...

Here is a photo of the back of the QBS. Loosening the two knobs at either end lets you adjust the angle of the rail the counterweights are move along. The nuts are holding the Vixen dovetail rail onto the mounting plate and the counterweight rail. The nuts and flat head machine screws are 1/4-20. It looks like you could substitute the 1/4-20 screws for longer 6mm ones and screw these directly onto your rings. You still might need the dovetail as a spacer because the of the depth of the knobs.

Interesting. I must e-mail Raul and ask how that works in practice.

Thanks again, Kevin!

Wow, very cool set up.

Kevin, Do you feel comfortable picking up the total assembly and carrying out the door?

t.r. - Yes, I am comfortable carrying the mount and tripod together out the door or loading them into my car. I haven't had them seperated since I received the mount. The mount and tripod together weigh 26.5 lbs., the mount with the QBS and counterweights attached is 15.5 lbs of that.

I actually meant with the scope attached as well, just out the door for observing in grab and go style.