Counterweight Bar Accessory Mount for GEM Mounts
CBAM is an aluminum block that clamps on the counterweight bar on GEM
mounts that have 18mm or 20mm diameter bars, to provide mounting
points for a variety of accessories.
The biggest benefit of mounting accessories on the counterweight bar is to
save weight when dressing out your setup with gizmos. When you add a
gizmo on the top of the mount, you often have to add weight to balance the
RA axis. That weight is the big enemy unless you spent a gazillion bucks
on a monster mount.
A wobbly scope sucks and adding toys to the setup (with the corresponding
counterweights) increases the suckage. Don't add suckage, distribute your
stuff on the mount! You might even decrease total weight.
If you have to add weights on the top side of your rig to balance a scope
in declination, instead you can move some balance weight off-axis and fix
the balance without having to add more weights on top.
As always, with some GEM configurations you can crash your main scope
or counterweights into a tripod leg if you don't plan ahead. Check your rig
before you turn off the lights and let it slowly track to a crash.
#CBAM is the basic mounting block with the clamp screw and allen wrench.
Accessories listed below, when ordered with #CBAM block, come with
stainless steel hardware for mounting the accessory to the block. Please
let us know if you have something else to mount and we can help with the
Thanks to Mike Weasner for generous support and photos!
CBAMs with accessories - Click on images to enlarge:
CBAM with Extension shaft for off-axis weight mounting, One pound weight off axis:
CBAM & SLR with a 1/4-20 bolt, SLR mounting using a ball-head:
CBAM block details, top and bottom:
CBAM block, top and bottom:
Before you order:
Check your mount to verify that the counterweight bar (shaft) rotates
with the right ascension axis movement of the mount. If the bar doesn't
rotate, neither will accessories mounted on the bar.
Measure your own counterweight bar before ordering. Don't guess or ask
the interweb, please measure the diameter!
Prices include shipping in the USA!