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Cheap Counterweights?

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#1 Acer

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Posted 05 December 2019 - 09:36 PM

I'd like to get a few more counterweights for my EQ6-R Pro.  Right now I have the extension rod on the counterweight bar and both counterweights nearly to the bottom of the extension.

I'd like to pick up a couple more counterweights and not use the extension at all.  My problem is, counterweights are EXPENSIVE!!! tongue2.gif

 

I am wondering if anyone knows where I can pick up counterweights for cheap?  I just can't see spending over $5.00 per pound for some cast iron.


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#2 PirateMike

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Posted 05 December 2019 - 09:47 PM

Make cement ones.

 

I have never tried to do it but I'm sure it could be done with a few short pieces of PVC pipe and maybe a few other pieces of cheap hardware.

 

Some good information about working with cement and molds and to help get the inventive juices flowing can be found here... https://www.youtube....h?v=yuSBwFkCiAw

 

 

Miguel   8-)

 

.


Edited by PirateMike, 05 December 2019 - 10:01 PM.

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#3 Hondo

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Posted 05 December 2019 - 09:50 PM

I needed some for my CEM60 and bought cast iron barbell weights from the local Walmart.  A little bit of work with a metal lathe and I saved a small fortune.


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#4 Xeroid

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Posted 05 December 2019 - 09:51 PM

Barbell weights on Amazon or Walmart

 

Use PVC tubing and glue to modify central hole diameter.

 

Rubber bands to secure the weight to your counter shaft. 


Edited by Xeroid, 05 December 2019 - 09:53 PM.

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#5 msl615

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Posted 05 December 2019 - 09:56 PM

Regardless of the solution you come up with (and the above ones are great ideas), you certainly want a larger mass than what you have now so that you can move the CW mass closer to the center of the mount. Having them far out on the CW rod can really induce significant vibrations into the mount, while getting them closer reduces the vibration. I am sure moving them in closer will be a big improvement. 

Mike


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#6 TxStars

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Posted 05 December 2019 - 10:00 PM

As said above, you can use barbell weights with a 1" center hole and enlarge the hole if needed or shim it with PVC or copper pipe.

Or use a drill bushing.

https://www.mcmaster.com/bushings

You can also get shaft collars to hold them in place.

https://www.mcmaster.com/shaft-collars


Edited by TxStars, 05 December 2019 - 10:02 PM.

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#7 John Fitzgerald

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Posted 05 December 2019 - 10:00 PM

I have made a couple nice ones from 4" PVC couplings, lead sinkers embedded for more weight, and concrete patching cement to hold it all together.  I use a 3/8-16 bolt with wing nut for a clamping bolt, and a piece of suitably sized pipe for the inside sleeve.  I have also made a couple of very compact weights from solid lead with aluminum tubing for the inside and the same type of clamping bolt.  These require several coats of paint to seal in the lead.


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#8 Cfreerksen

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Posted 05 December 2019 - 10:11 PM

I'd like to get a few more counterweights for my EQ6-R Pro.  Right now I have the extension rod on the counterweight bar and both counterweights nearly to the bottom of the extension.

I'd like to pick up a couple more counterweights and not use the extension at all.  My problem is, counterweights are EXPENSIVE!!! tongue2.gif

 

I am wondering if anyone knows where I can pick up counterweights for cheap?  I just can't see spending over $5.00 per pound for some cast iron.

Howz about just under 4 bucks a pound. Prime...so at least you don't have to pay shipping.

 

https://www.amazon.c...11&rps=1&sr=8-6

 

Chris


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#9 John Rogers

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Posted 05 December 2019 - 10:18 PM

Will these work for you?:  https://www.cloudyni...s-15-lbs-total/

 

I don't know the seller, but it seems like a decent price to me.



#10 kevindt

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Posted 05 December 2019 - 10:32 PM

If you have local thrift stores like Goodwill, take a look around.  I've often found barbell weights at low prices, and I once found a whole stack of 10# and 20# plastic-coated weights from a weight machine pretty well for free since no-one wanted them.  (I was looking for weights to hold down a canopy awning on concrete, where its tent spikes wouldn't be of any use, so I was really pleased).


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#11 TOMDEY

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Posted 05 December 2019 - 10:43 PM

I actually got over 600 free pounds of lead and cast my own. The nice thing about lead is that the weights are much more compact that iron... because it's 143% as dense. And if you really want compact counterweights... use pure gold! Its 244% as dense. Or go for the best, and use pure platinum, which is 272% as dense.

 

Note: some weights on satellites are actually made of gold or platinum, where compact trumps cheap. That will quite literally pay for itself many times over.

 

Here's a picture of a lead brick that I cast. I have piles of those and other shapes and sizes too. Heaviest one is 100 pounds. The gold and platinum ones are here and there in the barn, garage, domes, etc. So many I lose track.

 

I got the lead by volunteering to rake the sand down-range at the gun club. And when I melted it... fould a lot of casings floating to the top along with the usual slag! Hmmm...  Tom

Attached Thumbnails

  • 56 cast lead weitght.jpg

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#12 Littlegreenman

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Posted 05 December 2019 - 10:59 PM

Plutonium is even heavier, I think?

 

Any large sporting good store should have dumbell weights. No shipping either. Any large hardware store should have clamps to hold them in place,  although I like the idea of pvc or copper shims TxStars suggests above.

 

Ah! Osmium

https://sciencing.co...st-8751708.html


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#13 Migwan

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Posted 05 December 2019 - 11:12 PM

I agree with Tom.  If you have a propane torch, a couple of wide tuna cans and some lead, your in business.  Simply melt the lead into the cans and when cooled, peel the can off and drill a hole through them.   

 

I found a couple of ingots, one at a garage sale a friend's wife was having.  We were supervising while filling up with essential fluids.  

 

Price seems too good to be true, but here's a possibility.   Lead     Also some sporting good stores sell ingots for reloading.

 

jd


Edited by Migwan, 05 December 2019 - 11:15 PM.


#14 zxx

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Posted 05 December 2019 - 11:25 PM

Celestron wants $80 for a 12lb for my CGEM DX ,   Nope,   10lb barbell weight , 1.25" pipe and 1/4-20 knob and a few minutes with my welder. Then made a sheet metal sleeve that fit the pipe so I wouldn't mar up the shaft.

 

weght.jpg


Edited by zxx, 06 December 2019 - 10:52 AM.


#15 RalphMeisterTigerMan

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Posted 06 December 2019 - 12:43 AM

While I agree that counter-weights can be expensive, the part that hurts the most is the shipping. In some cases the shipping cost can either meet or even exceed the price of the actual counter-weight themselves.

 

Do yourself a favour and check on the price, no matter if it's USPS or any of the courier shipping companies, on dollars per pound or kilogram and distance that it has to travel to get to you. Even if you buy from a local vendor, remember that they also have incur the shipping costs and then have to charge you enough to to cover the costs of the counter-weight, the shipping and still make a profit so that they can pay the bills (lease, wages, taxes, etc, etc.) so I think you get the idea.

 

Not trying to make excuses but explain why things can cost so darn much.

 

Good luck in finding suitably priced counter-weights. That was not meant to be sarcastic!

 

Clear skies!

RalphMeisterTigerMan


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#16 photomagica

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Posted 06 December 2019 - 01:41 AM

Bill's policy on counter weights:

  • If you use the real thing never buy new unless you have to. Be patient and get them on CN if shipping doesn't kill you. I did buy a new one recently but got a smoking deal on Amazon Prime - no shipping.
  • Barbell weights are great if their larger diameter isn't an issue.
  • I've also collected scrap lead and scrap wheel weights from a tire shop.
    • When you melt the lead, the debris including the steel tire clips just float to the top and can be skimmed off. BE CAREFUL!!!
  • Alternatively you can just mix the lead in with a can full of thin concrete with a tube in the middle for a center hole.
  • If you need help advertise on CN for someone nearby who is willing to do a little machining or welding for you.

Let us know what you do.



#17 barbarosa

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Posted 06 December 2019 - 01:48 AM

The EQ6-R pro had a 25mm  or .98" counterweight shaft diameter. If you shop around you can find inexpensive barbell weights spec'd to fit a 1" bar.

 

The holes in the cheap weights are not made with much precision. They can be too large or too small, slightly oval or not at 90 degrees to the disk.  What I did was to make up a simple gauge block from a paint stick and visit the nearest sporting goods chain store. About  one out of  three weights was the right size or close enough for a bit of cleanup.

 

These barbell clamps are strong enough to hold several weights in position and fit a range of diameters.



#18 TxStars

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Posted 07 December 2019 - 04:12 AM

When sending counterweights USPS is your friend..

USPS flat rate boxes.. "If it fits it ships"   lol


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#19 jcj380

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Posted 07 December 2019 - 10:58 AM

For people without lathes, welding gear, torches, etc., what about fast-set concrete?  $6 for 50 pounds at Lowes.  Buckshot or fishing sinkers embedded in casting resin?  Use those barbell clamps so no drilling needed. 


Edited by jcj380, 07 December 2019 - 11:00 AM.

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#20 seasparky89

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Posted 07 December 2019 - 11:32 AM

I’ve used plastic covered barbell weights (larger center hole) sandwiched between the 2 stock Atlas weights. Worked fine.
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#21 SteveInNZ

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Posted 07 December 2019 - 03:26 PM

Celestron wants $80 for a 12lb for my CGEM DX ,   Nope,   10lb barbell weight , 1.25" pipe and 1/4-20 knob and a few minutes with my welder. Then made a sheet metal sleeve that fit the pipe so I wouldn't mar up the shaft.

For my EQ8 which also has a 1.25" bar, I bought "Olympic" barbell plates with a 2" hole and used one of the many 2"-1.25" eyepiece adapters that I seem to have collected. No welding or drilling involved.

 

Steve.


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#22 KLWalsh

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Posted 08 December 2019 - 04:09 PM

As msl615 pointed out, it’s better to have a heavier mass closer to the center of rotation than a small mass further from the center of rotation.
For equal torque: M1L1 = M2L2,
(M1>M2, L1<L2)
The rotational inertia is less for the large mass, shorter distance configuration because rotational inertia goes as the square of the distance:
M1L1^2 < M2L2^2

Lower rotational inertia means faster response from the motors and less wear on them.

Edited by KLWalsh, 08 December 2019 - 04:10 PM.

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#23 OldManSky

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Posted 08 December 2019 - 11:42 PM

As a side note to this, I was browsing counterweight prices today...the $40 or $60 for a 20-lb. one for iOptron or Skywatcher mounts, it's a little high, but not bad (not counting shipping).  I can even see the value in the $150 to $200 AP charges for their very nice stainless steel ones.  But Takahashi...there was a 20-lb. counterweight for EM-200 mounts that was over $450 that I saw.  And it's just painted metal, not stainless or anything fancy.  I mean, seriously...!


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#24 SonnyE

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Posted 10 December 2019 - 10:09 PM

I needed to go the other way.

An 11 pound counterweight had to ride too high and hit the ELV lock screw on my AVX.

So, I heated up my lead pot and filled a couple of small cans. Then drilled them and put a piece of EMT (electro metallic Tubing) (thin walled conduit) in them.

Made some smaller diameter counter weights.

I merely used a couple of Breeze Clamps to hold them in place. (Hose clamps)

 

(OK, if you really must know, a tuna can and a diced Jalapeno can.)


Edited by SonnyE, 10 December 2019 - 10:11 PM.

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#25 tiny68

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Posted 11 December 2019 - 01:36 PM

I made a couple of these for friends.  I don't have a finished picture of one.  You can buy the collars in about any size you want to make fit your bar.

 

Luck, Tim

 

https://www.cloudyni...er-weights-diy/


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