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Shmals
sage


Reged: 04/18/06
Posts: 370
Loc: Tornado Alley
Homemade counterweight ideas.
      #1167300 - 09/26/06 07:50 PM

Hello all,

I am currently in the middle of rebuilding my Alt/Az mount and I had a question to pose to the group. Without getting to into the design I will be needing a counterweight shaft and counterweights, it will be attached to the mount in a horizontal position (hanging off the end of the mount), parallel to the ground. As many of you know nice counterweights are expensive and shipping is just as bad. I would like to stick to a homemade design as well.

So finally my question: I would love to hear some homemade ideas for a counterweight system as described above, I will be needing about 10-12 lbs of counterweight. I have access to a few smaller hardware stores and a home depot to get the materials from. inspire me past my "builders block".

Thank you.

--------------------
Tom
254mm Meade-ish StarFinder EQ
203mm Conical Starhopper
60mm Monolux Circle-T


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Alan French
Night Owl


Reged: 01/28/05
Posts: 4009
Loc: Upstate NY
Re: Homemade counterweight ideas. new [Re: Shmals]
      #1167346 - 09/26/06 08:14 PM

I have followed the example set by Pierre Schwaar for the counterweights supplied with his mounts. The counterweight is made of two wood disks with a short length of pipe running down their middle. Around the outside is some flashing. This container is filled with lead shot through a small hole in one disk, which is then plugged. The shaft runs through the piece of pipe, and is secured by a bolt going through a theaded hole in the pipe (the pipe is a bit longer than the distance between the outer faces of the disks). A handle can be added to the bolt. In one version, I drilled a larger hole in the pipe, and the threaded portion for the tightening bolt was on one of the wood disks. You could certainly make any sort of container for the lead shot.

I could supply some photos if this sounds like something you want to pursue.

Clear skies, Alan

Edited by Alan French (09/26/06 08:16 PM)


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Art Bianconi
Post Laureate


Reged: 03/06/06
Posts: 4659
Loc: Delaware River Valley, New Jer...
Re: Homemade counterweight ideas. new [Re: Shmals]
      #1167439 - 09/26/06 09:08 PM

I'd be very surprised if Loew's or Home Depot carried lead.

Here one suggestion: find a resource for lead shot as was once popular with shot gunners. It comes in different sizes, the advantage being you can micro balance the scope by adding shot.

Afterwards, mix an appropriate amount of epoxy and pour it into a mold along with the shot and let it cure to a shape that fits the mirror box.

You should be close on the weight.

Lead was banned from gunning because of environmental concerns so the amount still on the market is dwindling. You may have to Google a bit, but you will find it.

Rboe is into gunning too. Perhaps he knows a resource.

Last batch of weights I made, I melted the lead on the kitchen stove and poured it into cat food tins. Then I simply drilled out the center, and slid it up the shaft.

Art


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rmcpb
Carpal Tunnel


Reged: 11/16/04
Posts: 1606
Loc: Blue Mountains, NSW, Australia
Re: Homemade counterweight ideas. new [Re: Art Bianconi]
      #1167615 - 09/26/06 10:39 PM

Ever thought of going to the sports store and getting some weight disks of the right weight and the little clips to stop them moving then setting them up on a pipe so they can be slid along it to atain balance?

--------------------
Rob Browne

8" & 13" Dobs
Equatorial Platform
Couple of Panoptics and a handful of BO/TMBs
9x60 binocs


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Shmals
sage


Reged: 04/18/06
Posts: 370
Loc: Tornado Alley
Re: Homemade counterweight ideas. new [Re: rmcpb]
      #1167628 - 09/26/06 10:46 PM

I would like to see a picture if you got one handy Alan! Rob I have thought of this, my fall back is to take 4 2.5lb weights and epoxy, jbweld them all together, a 10lb weights diameter is almost 10 inches (on the one I have), whereas the 2.5lb ones are only 3.5-4" in diameter. This is helping me get a few ideas, if you have another one please chime in, i'm all ears!

--------------------
Tom
254mm Meade-ish StarFinder EQ
203mm Conical Starhopper
60mm Monolux Circle-T


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rmcpb
Carpal Tunnel


Reged: 11/16/04
Posts: 1606
Loc: Blue Mountains, NSW, Australia
Re: Homemade counterweight ideas. new [Re: Shmals]
      #1167657 - 09/26/06 11:05 PM

I wouldn't weld them together I would use the small clamps weight lifters use to stop them coming off the end of the bar so you can change the configuration as you need. Keep it flexible.

--------------------
Rob Browne

8" & 13" Dobs
Equatorial Platform
Couple of Panoptics and a handful of BO/TMBs
9x60 binocs


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Pedestal
Post Laureate


Reged: 03/11/06
Posts: 4374
Loc: Smoggy Bottom, Baytown,Texas
Re: Homemade counterweight ideas. new [Re: Shmals]
      #1167664 - 09/26/06 11:06 PM

I just made a counterweight a couple of weeks ago from a "weight lifters" weight. This was a small one, 5 lbs if I remember. The weights a quite cheap. Cheaper, I'm sure, than buy lead and epoxy to make a weight (although I'm sure that would work).
Google Graf's/Cabela's/Gander Mountain for lead shot (yes, you can still buy it.)
Hubert

--------------------

Hubert
---------------------------------
www.smoggybottom.org





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Michael Miles
professor emeritus


Reged: 02/11/05
Posts: 730
Re: Homemade counterweight ideas. new [Re: Pedestal]
      #1167766 - 09/27/06 12:28 AM

Hey Thomas:

I use barbell weights too. You can bush out the hole in them with 3/4" PVC pipe. I usually have one good weight with a good clamp on the bottom (GEM mount), and then put the cheapos above it fixed with a small spring carpenters clamp. My LXD 75 came with one good weight, and I've got an old mount that has an aluminum bushing in the barbell weight drilled and tapped for 1/2". You can also get the rubber seats out of PVC couplers instead of the PVC pipe.

Cheapskate,

Michael

--------------------
LXD-75 w/
Stellarvue 102ED
Hardin 10" Newt
Antares 8" Newt
Meade AR-5
Meade N-6
Celestron 102mm refractor
Canon 300D, Meade DSI guiding


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GordonCopestake
Carpal Tunnel


Reged: 03/02/06
Posts: 2715
Loc: Newcastle-under-Lyme, UK
Re: Homemade counterweight ideas. new [Re: Michael Miles]
      #1167878 - 09/27/06 03:12 AM

as mentioned, gym weights are the best way to go

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Jeremy@za
professor emeritus


Reged: 02/28/05
Posts: 704
Loc: Cape Town, South Africa. 33 56...
Re: Homemade counterweight ideas. new [Re: GordonCopestake]
      #1167879 - 09/27/06 03:21 AM

If gym weights don't work, find yourself some second hand diver's weights. They're probably 500 grammes to a kilogramme per weight, and should be available at any second hand sports store or diving equipment store.

Jeremy

--------------------


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gazerjim
Postmaster


Reged: 02/12/04
Posts: 8166
Loc: n-dimensional space
Re: Homemade counterweight ideas. new [Re: Jeremy@za]
      #1167917 - 09/27/06 05:15 AM

Hmmm I've never made one from scratch; but seems like there might be some way to drill and tap heavy walled tubing or pipe for the clamp and then cast some kind of steel reinforced concrete (maybe one of the finer grades like vinyl concrete) around it with a large diameter can or even a short section of sonotube. Not sure how the ends would be plugged.

I know this isn't specific; just a kind of musing.

Jim

--------------------
Jim Fisher

"How wonderful that we have met with a paradox. Now we have some hope of making progress."

Niels Bohr


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GordonCopestake
Carpal Tunnel


Reged: 03/02/06
Posts: 2715
Loc: Newcastle-under-Lyme, UK
Re: Homemade counterweight ideas. new [Re: gazerjim]
      #1167962 - 09/27/06 06:55 AM

I guess a tin can with a wooden dowel inside the same diameter as your counterweight shaft and then filled with smooth concrete might work. The base could then be drilled out. Not sure how you would manufacture an adjustment screw though perhaps just have it sit on top of a normal counterweight.

If making your own one thing to remember though is that safety is very important! If this thing slips down your counterweight shaft make sure that the safety washer at the end WILL stop it as you dont want it landing on your foot or worse your set of naglers


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Wallrat
member


Reged: 08/29/06
Posts: 84
Loc: Huntington Beach, Ca
Re: Homemade counterweight ideas. new [Re: Shmals]
      #1167987 - 09/27/06 07:37 AM

I'm currently making a CW system for a member on here. If you throw out some designs we could probably work something out. Here's the one I'm making now (substitude all thread for the 12" rod): LINK

--------------------
Matt

Welder For Hire

10" LX200GPS
W.O. ZS66SD
Canon 300D
QC Pro 3000
Homemade portable pier & wedge
PowerMac G5 Dual & Powerbook G4


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Jim Easterbrook
professor emeritus


Reged: 02/25/04
Posts: 564
Loc: Surrey, UK (N51.36 W0.25)
Re: Homemade counterweight ideas. new [Re: Wallrat]
      #1167999 - 09/27/06 07:58 AM

I have a friend who casts lead diving weights. I made a tin can mould and he poured the lead as described on my web site.


--------------------
Jim (N51.36 W0.25)
9" SCT & 4" Mak. 6" f/5 achro, 80mm f/7.5 apo & 66mm f/5.9 apo refractors.
EQ-6 SkyScan & NexStar 80 mounts. CoolPix 4500 & EOS 350d cameras.


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Wallrat
member


Reged: 08/29/06
Posts: 84
Loc: Huntington Beach, Ca
Re: Homemade counterweight ideas. new [Re: Jim Easterbrook]
      #1168054 - 09/27/06 08:49 AM

The drawback to using lead is that you don't want to be handling that stuff and then eating, rubbing your eyes, picking your nose, etc. If you use lead, you might want to get some of that rubber tool grip stuff (sold at any home improvement store) and coat the CW with it.

--------------------
Matt

Welder For Hire

10" LX200GPS
W.O. ZS66SD
Canon 300D
QC Pro 3000
Homemade portable pier & wedge
PowerMac G5 Dual & Powerbook G4


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strix
sage


Reged: 07/21/05
Posts: 288
Loc: southern Chile
Re: Homemade counterweight ideas. new [Re: Shmals]
      #1168095 - 09/27/06 09:29 AM Attachment (67 downloads)

Hi Thomas,

May this simple idea could help:

"Due to a lack of scraps for my on course azim. mount, I noticed that the counterweight shaft of a flimsy GEM that I have was really short and of no worth at all. Scavenging for a sort of rod longer I found some old shock absorbers and their chrome shining ends lured me enough. Using my beloved hacksaw I cut one shock absorber (only the two outer tubing; dispose fluid properly, it's oily and rather stinky...) and... what a beautiful shaft we have, with an additional small weight on the end. As a bonus I got some tubing for whatever (the inner one). From the vernier caliper to top are: the miserable original shaft, the new one with the original counterweight plus the bonus one, and of course, a used shock abs. Sorry if I re-invented the wheel but it was a pleasure to see the amount of valuable ATM parts an old shock abs. could provide."

I've posted it at Astronomy Daily some time ago 'cause the quote. In addition, follow Jim's idea of melting some lead. Just go to any tire repair shop and ask for those discarded lead counterweights. Here, you can take any for free or they ask for some coins...

Best regards,

David

Attachment

--------------------
Homemade 80 mm f/5 refractor (Starcat)
Homemade 80 mm f/11.3 refractor (Astrix)
Homemade 83 mm f/12 refractor (Astrix-Jaegers)
Homemade 114 mm f/8 newtonian (Silverghost)
UNITRON 105 mm f/15 refractor (older than me...)


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Jim Easterbrook
professor emeritus


Reged: 02/25/04
Posts: 564
Loc: Surrey, UK (N51.36 W0.25)
Re: Homemade counterweight ideas. new [Re: Wallrat]
      #1168119 - 09/27/06 09:46 AM

Quote:

The drawback to using lead is that you don't want to be handling that stuff and then eating, rubbing your eyes, picking your nose, etc.



I think that's rather overstating the risks. In normal handling, solid lead is not a problem. Obviously, don't scratch bits off the surface and eat them, but otherwise it should be OK. Most handling is of the outer tin can, anyway.

UK Health & Safety Executive leaflet on lead (PDF file, 23kB)

Quote:

If you use lead, you might want to get some of that rubber tool grip stuff (sold at any home improvement store) and coat the CW with it.



I've not seen that here in Europe, but I plan to paint the weight black at somepoint anyway.

--------------------
Jim (N51.36 W0.25)
9" SCT & 4" Mak. 6" f/5 achro, 80mm f/7.5 apo & 66mm f/5.9 apo refractors.
EQ-6 SkyScan & NexStar 80 mounts. CoolPix 4500 & EOS 350d cameras.


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kestrel0222
Carpal Tunnel


Reged: 05/21/06
Posts: 2339
Loc: Milford, Michigan
Re: Homemade counterweight ideas. new [Re: Jim Easterbrook]
      #1168145 - 09/27/06 10:10 AM

I had some counter weights left over from the EQ set up that I had a while ago. I used them when I made my own ALt/Az mount, they work great!

--------------------
Tom





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Alan French
Night Owl


Reged: 01/28/05
Posts: 4009
Loc: Upstate NY
Re: Homemade counterweight ideas. new [Re: kestrel0222]
      #1168179 - 09/27/06 10:27 AM Attachment (52 downloads)

Here is a photo of a counterweight made with two plywood disks, a short length of pipe, some flashing, and lead shot. This one is for a 14.5" f/6 Newt, so it is heavy at 56 pounds. It also has clamping bolts on both sides because of the weight (and there is a safety stop on the RA axis below the weight).

Each clamping bolt uses a hitch pin as a handle. The inside of the square black block has a T-nut, which the end of the clamping bolt passes through. There is a hole in the inner pipe that allows the clamping bolt to pass. There are some brass shims epoxied to the inside of the pipe, opposite to the clamping bolt, to provide a somewhat snugger fit on the RA shaft (otherwise the counterweight is too eccentric and can cause balance problems).

This is overkill for the request at hand, but the general idea can be used for much smaller weights. I'd rather work with lead shot than melt lead. (For modest weights pouring a little concrete beats melting lead, and a variety of free weights at your local sports store are useful, as others have mentioned. I've found ankle weights very handy for balancing scopes.)

Clear skies, Alan

Attachment

Edited by Alan French (09/27/06 10:29 AM)


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NeoDinian
Experienced Postmaster


Reged: 10/05/05
Posts: 14043
Loc: Rockford Illinois
Re: Homemade counterweight ideas. new [Re: Jim Easterbrook]
      #1168442 - 09/27/06 01:20 PM

Quote:


Quote:

If you use lead, you might want to get some of that rubber tool grip stuff (sold at any home improvement store) and coat the CW with it.



I've not seen that here in Europe, but I plan to paint the weight black at somepoint anyway.




What I've seen is not a pain, but just a liquid you "Dip" into. (Rubberized). You can re-coat things like the handles on your pliers. I actually think it was called "Grip-Dip" here at my local Ace Hardware.

--------------------
Neo... (Jeff)
-=-=-=-=-=-=-
10" LX200-GPS/SMT UHTC "Draco"

Rockford, Il.

NeoDinian's Eye on the Sky!

Coming soon:


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