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Equipment Discussions >> Reflectors

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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Big Dob, Big Back Pain......
      #6115089 - 10/03/13 12:42 PM

My 16” f/5 Zambuto/TeeterDob is causing me a great deal of back problems due to the awkward standing positions for viewing. My observing sessions inevitably end, not because I am tired or cold but because of the ache in my back. Consider that I play ice hockey 2x a week all year round and softball 3x a week in the summer, ride a bike, go for long walks etc. etc. without any back pain at all. But looking through my scope slightly bent over because the eyepiece is at my chin height causes a dull throb which only partially goes away when I sit to look at a chart or computer. As the evening wears on, the pain becomes cumulative...

We have had 5 near-perfect nights in a row here at OkieTex and I have not made it past 2:30 am at all.....
What a waste!!

I have tried a large “Catsperch” observing chair but my height and weight made it very unstable to climb up and down from - impossible, actually, as it over-balanced if I didn’t climb up just right. (While seated it was fine - it was the climb...)

I have an idea which will, possibly, provide a solution. I will outline it here for your amusement and, hopefully, your wise suggestions and advice

I propose to replace the 16” f/5 Zambuto mirror with a 16” f/4 or f/3.8 Mike Lockwood mirror (depending on my maximum seated ‘eyeball-height’ which I have yet to measure), shorten the poles and replace the 3.1” secondary with a 3.5”. I would keep the rest of the Teeter structure as-is - it is excellent in every way.

I would sell the Zambuto mirror which would cover about 70-80% of the cost of the Lockwood mirror. (f/4 mirrors require more time and effort to make and, therefore, are more expensive....) I am confident I will have equal quality from Mike as from Carl Z.
I would also sell the 3.1” diagonal and buy a 3.5” from the same company...

The most obvious potential problem would be balance. Shortening the poles will change the center of gravity - the UTA end may become too light. However: My scope was ordered from Rob Teeter at a time when he was switching mirror cell providers and the cells went from steel to aluminum during my scope build. So my rocker box is not quite tall enough to put the center of gravity in the right spot and the UTA is too heavy. I agreed to this because I didn’t want to wait several more months and because the solution was so simple - I have added about 10 pounds of weights to the back of the cell. The weights are ‘out of sight, out of mind’ but are easily removable to balance the shortened scope.

Another potential spot of trouble - the secondary mirror offset will be greater for an f/4 or f/3.8 system. Easily solved, though, I suspect.

So, for about $1000 or so my scope could be altered to allow me 100% seated viewing and with zero loss in optical quality....

And no more back pain.

Thanks for listening,

Dave


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woodscavenger
sage


Reged: 08/20/13

Loc: Boise, ID
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6115189 - 10/03/13 01:26 PM

sounds cheaper and easier to hire a massage therapist for every night of viewing! Good luck on getting things figured out

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cloud_cover
professor emeritus


Reged: 08/17/10

Loc: Restaurant at the End of the U...
Re: Big Dob, Big Back Pain...... new [Re: woodscavenger]
      #6115397 - 10/03/13 03:07 PM

Have you tried kneeling with one or both knees on your observing chair while keeping your back straight? It might help if the chair is of the right height.
You might also want to consider some sort of a back brace when observing to keep the back straight


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Jon Isaacs
Postmaster
*****

Reged: 06/16/04

Loc: San Diego and Boulevard, CA
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6115442 - 10/03/13 03:30 PM

Dave:

I think your plan is a good one... It may not solve your problem completely, but it certainly should help..

A few thoughts:

- I have a Catsperch chair for my 16 inch F/4.42. It took me the longest time to figure out that if I set the chair parallel to the scope rather than partially facing the scope, I could easily climb up and then sit comfortably sideways on the chair. Prior to that revelation, I was reluctant to use it because it was awkward to climb, it felt quite unstable.

- Consider a small rolling ladder for your 16 inch F/5... Jeff has one for his 16 inch F/7, I have one for my 25 inch F/5.

- There is always the smaller scope.. I have a lot of fun with my 12.5 inch F/4.06, it's easy all the way, it's seated all the time.

Jon


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azure1961p
Postmaster
*****

Reged: 01/17/09

Loc: USA
Re: Big Dob, Big Back Pain...... new [Re: Jon Isaacs]
      #6115502 - 10/03/13 03:57 PM

Cotts!!

I feel your pain. After several go around with a chiro my back was fixed but there's a preventative lesson learned here that Ill pass along. At nights I tattoo in my wife's shop. Over time my lower back really started giving me pain. I too am active, kayaking, bicycling, archery etc. and it affected all of this. The culprit it turned out was my chronic posture of leaning over to reach an arm, back, leg etc at the proper angle. That curved spine all the time finally did a number in me.

Two things solved it away....

I am now conscientious about propr seat height of me and the client. That's important. I raised the bench - literally. But this is only half the fix.

Next I turned my chair around BACKWARDS. I support my chest with my seat back. My lower back is no longer carrying ALL the load. What a difference Dave.

Lastly - compresses. If you are sore - lose the heating pad. My chiro told me for a month to and I ignored him. Afterall it feels so good right? But I wasn't getting better fast enough.

I finally caved in.

I got a bag if frozen peas and I'd lay on it at night right on the spot. Fairly quickly I felt these quiverings in my back like involuntary twitches. Hmmmm never felt that before. I stayed with it for three nights right before bed and I finally actually began recovery.

Frozen peas - who knew? Doc said heat can cause muscle congestion in my back while cold can reduce inflammation and congestion. The twitchings and quiverings was my wrecked back " giving it up" to the cold compress.

I am now a true believer in cold compresses.


I should add Dave - my tattooing at night posture didnt cause the injury. Rather it was me improperly moving kayaks onto the car into the water and vice versa. My night time job aggravated it.

Next time out if you can lean on your chest rather than curving your back you'll do a lot better. Get out the peas if you hurt yourself or over did it.

Good luck.

Pete

Edited by azure1961p (10/03/13 04:00 PM)


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AlBoning
professor emeritus


Reged: 03/06/11

Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6115556 - 10/03/13 04:14 PM

Wouldn't it be technically easier and a whole lot cheaper just to raise the scope so the eyepiece is at a comfortable seated height? Or did I miss something? And rather than climb the Catsperch how about a stepstool?

[Edit]

OH! I get it now, it's at chin height when you are standing. No wonder using a chair didn't make sense to me.

Edited by AlBoning (10/03/13 04:19 PM)


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Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6115600 - 10/03/13 04:34 PM

What is the angle of your eyepiece barrel relative to the ground? (Or put another way, what is the angle of your focuser?)

On larger scopes I have found the 45 degree focuser position to create more leaning over/around the tube, inducing low back pain.

Having the focuser at the zero degree location (parallel to the ground) eliminates this for me.

If this was the cause of your problem, it would be a whole lot easier (and cheaper) to change.


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Jeff Morgan
Postmaster
*****

Reged: 09/28/03

Loc: Prescott, AZ
Re: Big Dob, Big Back Pain...... new [Re: Jon Isaacs]
      #6115617 - 10/03/13 04:42 PM

Quote:

- Consider a small rolling ladder for your 16 inch F/5... Jeff has one for his 16 inch F/7, I have one for my 25 inch F/5.




A big ladder, but quite amazing. Incredibly stable. I can lean, lay, sit, or stand on it. The rails are nice for bracing against or wrapping an arm or even leg around (yes, you can lean waaaay off to the side as your scope tracks away from it). And it makes possible a very large scope.


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Kevdog
Pooh-Bah
*****

Reged: 07/11/12

Loc: Desert Hills, AZ
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6115720 - 10/03/13 05:27 PM

Wouldn't a small platform to put the scope on be easier? Even just a short box that you can roll the scope up onto to raise the height about 3-4"? Cost at HD probably $50?

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csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Big Dob, Big Back Pain...... new [Re: Kevdog]
      #6115947 - 10/03/13 07:51 PM

I think the XT10 was designed by a short fat person like me......

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BoldAxis1967
sage
*****

Reged: 10/11/12

Loc: Kentucky
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6116035 - 10/03/13 08:49 PM

Until you create a friendly ergonomic environment, I, like Azure1961p, have found ice to be the closest thing to a panacea. Twenty to thirty minutes of frozen peas reduces my neck pain significantly. You might want to take about 400 to 600 mg of Ibuprofin before observing. (Chronic use of Ibuprofin can be very dangerous!)

You did not indicate (or I missed it) if your pain is muscular and/or isolated to a specific area of your vertebal column. If it is the later you might be aggravating a nerve that is otherwise not affected during your athletic activities.

LB


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Bill Weir
Carpal Tunnel
*****

Reged: 06/01/04

Loc: Metchosin (Victoria), Canada
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6116186 - 10/03/13 10:05 PM

Good plan Dave. Go with with f/3.7 then dimensions will match what Rob does with 16" scopes. Then he will be able to tell you exactly how much to cut off the poles. Eyepiece height will be 60" which will mean seated viewing all of the time and your feet will always be on the ground. None of that perched on a chair in the dark with your feet in some little pedistal. To me that's the same as climbing a ladder.

Be not afraid of going sub f/4 and Mike's mirrors are fabulous. It will require getting the new paracorr but then you will also be able to use it with your DSLR for imaging. Type 1 Paracorrs are easy to get rid of.

Bill


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soupaman
sage


Reged: 07/26/09

Loc: Not sure
Re: Big Dob, Big Back Pain...... new [Re: BoldAxis1967]
      #6116267 - 10/03/13 10:57 PM

Stretching will dramatically decrease fatigue and soreness while observing. Do some static stretches holding them for 20 seconds at least. There are too many types to list. It's easier to go to YouTube and get the visuals. Whatever you do don't ice before observing. After only if you feel aches and pains. Don't be afraid of ibuprofen unless you have liver issues. Just don't take it every day.
Don't think stretching won't help, it will. Pro athletes do it, as do people sitting behind a desk for 10 hours.


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bunyon
Post Laureate
*****

Reged: 10/23/10

Loc: Winston-Salem, NC
Re: Big Dob, Big Back Pain...... new [Re: soupaman]
      #6116667 - 10/04/13 07:51 AM

We're all very willing to practice medicine on the internet (even me!) but, if you haven't, you should probably see a real doc about it in case it is something fixable.

Now for my medicine, which is close to soupaman's. When I have a long session I stretch before and then make a point of stretching often and put in a break here and there where I lay flat on my back for 10 minutes or so. It's lousy to interrupt a good session but I find it helps when I have what sounds like very similar pain. I, too, am a big guy - not quite as big as you, but big enough. I find that any prolonged standing or, as you say, hunched a bit, causes the pain and I have a few stretches that help. It is just standing; I can walk all day but if I have to stay relatively motionless, the pain comes on regularly.

Anyway, I hope you get it worked out.


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Dick Jacobson
scholastic sledgehammer


Reged: 12/22/06

Loc: Plymouth, Minnesota, USA
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6116730 - 10/04/13 08:42 AM

If the eyepiece is at chin height while standing on the ground, you might try spreading your legs far apart to lower your head a few inches. For positions lower than this, I have a homemade gas-cylinder stool that adjusts instantly from 21" to 31" seat height. I have also built a ladder with half-step intervals for use with larger scopes. Many people have built half-step accessories for ladders.

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precaud
Pooh-Bah
*****

Reged: 12/05/12

Loc: north central New Mexico
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6116896 - 10/04/13 10:06 AM

Quote:

... back problems due to the awkward standing positions for viewing... Consider that I play ice hockey 2x a week all year round and softball 3x a week in the summer, ride a bike, go for long walks etc. etc. without any back pain at all.




Dave, I have felt your pain (or something similar to it!). I'm on the tall side (6'5") and have always had to deal with this in the sedentary activities I enjoy. Looking at the sports activities you listed, they all build strength and conditioning primarily from the waist down. Whereas observing needs conditioning over the whole length of the spinal column. Rather than popping pills to mask the discomfort, try doing some upper body exercises in a gym a few times a week. Since adding a 90-minute workout 2-3 times a week to my routine a few years ago, I haven't had a single back issue. No chiropractor, no pills, no pain.


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RAKing
Postmaster
*****

Reged: 12/28/07

Loc: West of the D.C. Nebula
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6117350 - 10/04/13 02:07 PM

Dave, I certainly feel your pain. In fact, my back started hurting as I was reading your post.

I think your plan is fine and I think it's a great idea to make the structure into something YOU can use. I have always considered Dobs to be 'kit scopes' anyway, so go ahead and make it fit you. You might also call Rob Teeter to double check the proper measurements, etc. for your poles and secondary.

I'm in similar shape. I have a 12 inch f/5 in the basement that I cannot use because of my back. I haven't figured out what to do with it yet, but a friend of mine told me that he is going to ask Carl to make a 12 inch f/4 mirror for his because it's too tall for his wife to use.

Sounds like a plan.......

Ron


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Dhellis59
member
*****

Reged: 08/31/12

Loc: Georgia, USA
Re: Big Dob, Big Back Pain...... new [Re: Cotts]
      #6117356 - 10/04/13 02:11 PM

Hi David,

I don't have so much the back pain as I just get tired of standing after a while. Also, I hate that my chair seems to have been rendered useless since moving from my former 10" to my current 14" dob. With my 10", the chair was probably one of my most cost effective purchases.

After reading your post, I decided to do some research and measuring. I found that Catsperch is now offering a Summit model that has a maximum seat height of 58". However, the idea of climbing and turning on anything off the ground in the dark is not appealing to me either. Particularly on uneven ground.

I have been contemplating shedding weight and height off of my dob by investing in the Hubble Optics light weight structure for a 14" for around $1300. http://www.hubbleoptics.com/ULstructure.html . If I can sell the base and structure of my current dob to an ATMer or owner of a solid tube looking to upgrade, it would help offset some of the cost. Of course then I couldn't resist using those funds to get the goto module etc., lol.

Doing so would effectively reduce the height of my dob by 5" and the weight by 60 lbs! Then I realized that I added about 5" to my dob by placing the locking coasters under the base board. The tradeoff has been that I just roll the whole thing out onto my driveway, lock it down, and start aligning and observing.

I think I hurt my back moving the beast more than observing through it in my case. As is, it is slightly below eyelevel at zenith at 65" for me. On the other hand, my ten inch required me to constantly bend over as you described.

I then measured my maximum seat height on my chair and found it to be at 33". It actually puts me at 65" sitting. But then I realized that the reason I don't use my chair as much is that where I place my dob for the best views in my driveway is on a 5 - 10 degree slope. Therein lies my problem.

All that to say, I understand your dilemma, and as you can see, I have gone through a similar thought process. I still plan to upgrade my structure though...(then again, I like that 18" full tele HO has on it's site as well.) I appreciate your thought process though, and it makes a lot of sense to me.

Best of luck with your decision, and clear skies.

Darryl


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Cotts
Just Wondering
*****

Reged: 10/10/05

Loc: Toronto, Ontario
Re: Big Dob, Big Back Pain...... new [Re: Dhellis59]
      #6117444 - 10/04/13 03:05 PM

Plenty of excellent, thoughtful replies. Thanks!

My pain at the telescope is broadly across my lower back and is muscular. (I am familiar with acute disc/fascia pain from a couple of episodes I've had. Much more severe and acute.)

I observe for about 15 minutes and sit in a chair for 5. The sitting lessens the pain some but it builds through the night.

I'll try stretching.

and I've talked extensively with mike lockwood about the mirror. Rob t. will be next on my list....

thanks, folks.

dave


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The Ardent
Pooh-Bah
*****

Reged: 10/24/08

Loc: Virginia
Re: Big Dob, Big Back Pain...... [Re: Cotts]
      #6117697 - 10/04/13 05:36 PM

Rob has shortened one of his dobs before to accommodate a faster mirror.

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