Sky & Telescope - December 2021 - 74

ASTRONOMER'S WORKBENCH by Jerry Oltion
Bowling Ball Mounts, Take 2
A closer look at an innovative spherical mount.
This brings up a happy coincidence:
If you're currently using a Newtonian
scope on an equatorial mount - one
of the most ungainly, awkward setups
known to mankind - you're in great
shape to do a bowling-ball conversion.
You already have the tube rings! If you
have a Dobsonian, you can either make
or buy tube rings or you can bolt the
tube box to the transverse shaft.
When you run the rod through the
Brett Tatton enjoys the ease of
use of his ball-mounted scope.
A SPHERE IN A CRADLE is arguably
the simplest, most convenient way to
mount a telescope. It enables easy oneaxis
movement in any direction, even
straight overhead and near the poles,
and it allows for comfortable eyepiece
placement as well.
Bowling balls are ready-made for
spherical mounts. In our July 2018 issue
I featured several bowling-ball mounts,
but I focused mostly upon the tracking
system that their builder, Doug
Arion, made for them. Inspired by that
column, Brett Tatton, of Port Elgin,
Ontario, Canada, has come up with a
great design, so in this installment let's
look at how he made the mount itself.
The basic concept behind the
bowling-ball mount is simple: Attach
the telescope to one side of the ball and
stick a counterweight out the other side
to balance it. Set the ball in some kind
of cradle, and you're done.
First, of course, you need a bowling
ball. A trip to the local lanes yielded
Brett a bright purple one for free. (Brett
thanks Port Elgin's Sunset Bowling for
74 DECEMBER 2021 * SKY & TELESCOPE
their generosity.) He used a long 5
/8-inch
wood bit in a large drill press to extend
the thumb hole all the way through,
and he bought a length of 5
/8-inch Ready
Rod (long, fully threaded rod) for the
transverse shaft. He ran it through the
ball and bolted it to a flat metal plate
that the telescope's tube rings mount to.
By moving the cradle off to the side and
cutting a slot in the pipe end cap (left), Brett
enabled the counterweight to hang straight
down while attaching and removing the telescope
(right).
ball, put a big rubber O-ring on either
side and add a pair of big washers
outside the O-rings. Now snug a nut
up against the ball from the long side,
pressing the O-rings against the ball.
That'll mate the curve of the ball to the
flat washers and keep the shaft from
turning inside the ball. (If the shaft
turns, friction on that axis won't match
friction in other directions, so the scope
will be harder to aim.)
Put a counterweight or two on
the other end of the shaft and secure
them in place with nuts, too. Another
advantage for those of you moving from
equatorial mounts: You have readymade
counterweights. But you can
ALL IMAGES COURTESY OF BRETT TATTON

Sky & Telescope - December 2021

Table of Contents for the Digital Edition of Sky & Telescope - December 2021

Contents
Sky & Telescope - December 2021 - Cover1
Sky & Telescope - December 2021 - Cover2
Sky & Telescope - December 2021 - 1
Sky & Telescope - December 2021 - Contents
Sky & Telescope - December 2021 - 3
Sky & Telescope - December 2021 - 4
Sky & Telescope - December 2021 - 5
Sky & Telescope - December 2021 - 6
Sky & Telescope - December 2021 - 7
Sky & Telescope - December 2021 - 8
Sky & Telescope - December 2021 - 9
Sky & Telescope - December 2021 - 10
Sky & Telescope - December 2021 - 11
Sky & Telescope - December 2021 - 12
Sky & Telescope - December 2021 - 13
Sky & Telescope - December 2021 - 14
Sky & Telescope - December 2021 - 15
Sky & Telescope - December 2021 - 16
Sky & Telescope - December 2021 - 17
Sky & Telescope - December 2021 - 18
Sky & Telescope - December 2021 - 19
Sky & Telescope - December 2021 - 20
Sky & Telescope - December 2021 - 21
Sky & Telescope - December 2021 - 22
Sky & Telescope - December 2021 - 23
Sky & Telescope - December 2021 - 24
Sky & Telescope - December 2021 - 25
Sky & Telescope - December 2021 - 26
Sky & Telescope - December 2021 - 27
Sky & Telescope - December 2021 - 28
Sky & Telescope - December 2021 - 29
Sky & Telescope - December 2021 - 30
Sky & Telescope - December 2021 - 31
Sky & Telescope - December 2021 - 32
Sky & Telescope - December 2021 - 33
Sky & Telescope - December 2021 - 34
Sky & Telescope - December 2021 - 35
Sky & Telescope - December 2021 - 36
Sky & Telescope - December 2021 - 37
Sky & Telescope - December 2021 - 38
Sky & Telescope - December 2021 - 39
Sky & Telescope - December 2021 - 40
Sky & Telescope - December 2021 - 41
Sky & Telescope - December 2021 - 42
Sky & Telescope - December 2021 - 43
Sky & Telescope - December 2021 - 44
Sky & Telescope - December 2021 - 45
Sky & Telescope - December 2021 - 46
Sky & Telescope - December 2021 - 47
Sky & Telescope - December 2021 - 48
Sky & Telescope - December 2021 - 49
Sky & Telescope - December 2021 - 50
Sky & Telescope - December 2021 - 51
Sky & Telescope - December 2021 - 52
Sky & Telescope - December 2021 - 53
Sky & Telescope - December 2021 - 54
Sky & Telescope - December 2021 - 55
Sky & Telescope - December 2021 - 56
Sky & Telescope - December 2021 - 57
Sky & Telescope - December 2021 - 58
Sky & Telescope - December 2021 - 59
Sky & Telescope - December 2021 - 60
Sky & Telescope - December 2021 - 61
Sky & Telescope - December 2021 - 62
Sky & Telescope - December 2021 - 63
Sky & Telescope - December 2021 - 64
Sky & Telescope - December 2021 - 65
Sky & Telescope - December 2021 - 66
Sky & Telescope - December 2021 - 67
Sky & Telescope - December 2021 - 68
Sky & Telescope - December 2021 - 69
Sky & Telescope - December 2021 - 70
Sky & Telescope - December 2021 - 71
Sky & Telescope - December 2021 - 72
Sky & Telescope - December 2021 - 73
Sky & Telescope - December 2021 - 74
Sky & Telescope - December 2021 - 75
Sky & Telescope - December 2021 - 76
Sky & Telescope - December 2021 - 77
Sky & Telescope - December 2021 - 78
Sky & Telescope - December 2021 - 79
Sky & Telescope - December 2021 - 80
Sky & Telescope - December 2021 - 81
Sky & Telescope - December 2021 - 82
Sky & Telescope - December 2021 - 83
Sky & Telescope - December 2021 - 84
Sky & Telescope - December 2021 - Cover3
Sky & Telescope - December 2021 - Cover4
https://www.nxtbook.com/nxtbooks/aas/st_202406
https://www.nxtbook.com/nxtbooks/aas/st_202405
https://www.nxtbook.com/nxtbooks/aas/st_202404_qr
https://www.nxtbook.com/nxtbooks/aas/st_202404
https://www.nxtbook.com/nxtbooks/aas/st_202403
https://www.nxtbook.com/nxtbooks/aas/st_202402
https://www.nxtbook.com/nxtbooks/aas/st_202401_aus
https://www.nxtbook.com/nxtbooks/aas/st_202401
https://www.nxtbook.com/nxtbooks/aas/st_202312_aus
https://www.nxtbook.com/nxtbooks/aas/st_202312
https://www.nxtbook.com/nxtbooks/aas/st_202311
https://www.nxtbook.com/nxtbooks/aas/st_202310
https://www.nxtbook.com/nxtbooks/aas/st_202309
https://www.nxtbook.com/nxtbooks/aas/st_202308
https://www.nxtbook.com/nxtbooks/aas/st_202307
https://www.nxtbook.com/nxtbooks/aas/st_202306
https://www.nxtbook.com/nxtbooks/aas/st_202305
https://www.nxtbook.com/nxtbooks/aas/st_202304
https://www.nxtbook.com/nxtbooks/aas/st_202304_qr
https://www.nxtbook.com/nxtbooks/aas/st_202303
https://www.nxtbook.com/nxtbooks/aas/st_202302
https://www.nxtbook.com/nxtbooks/aas/st_202301
https://www.nxtbook.com/nxtbooks/aas/st_202212
https://www.nxtbook.com/nxtbooks/aas/st_202211
https://www.nxtbook.com/nxtbooks/aas/st_202210
https://www.nxtbook.com/nxtbooks/aas/st_202209
https://www.nxtbook.com/nxtbooks/aas/st_202208
https://www.nxtbook.com/nxtbooks/aas/st_202207
https://www.nxtbook.com/nxtbooks/aas/st_202206
https://www.nxtbook.com/nxtbooks/aas/st_202205
https://www.nxtbook.com/nxtbooks/aas/st_202204
https://www.nxtbook.com/nxtbooks/aas/st_202203
https://www.nxtbook.com/nxtbooks/aas/st_202202
https://www.nxtbook.com/nxtbooks/aas/st_202201
https://www.nxtbook.com/nxtbooks/aas/st_202112
https://www.nxtbook.com/nxtbooks/aas/st_202111
https://www.nxtbook.com/nxtbooks/aas/st_202110
https://www.nxtbook.com/nxtbooks/aas/st_202109
https://www.nxtbook.com/nxtbooks/aas/st_202108
https://www.nxtbook.com/nxtbooks/aas/st_202107
https://www.nxtbook.com/nxtbooks/aas/st_202106
https://www.nxtbook.com/nxtbooks/aas/st_202105
https://www.nxtbook.com/nxtbooks/aas/st_202104
https://www.nxtbook.com/nxtbooks/aas/st_202103
https://www.nxtbook.com/nxtbooks/aas/st_202102
https://www.nxtbook.com/nxtbooks/aas/st_202101
https://www.nxtbook.com/nxtbooks/aas/skywatch_2021
https://www.nxtbook.com/nxtbooks/aas/st_202012
https://www.nxtbook.com/nxtbooks/aas/st_202011
https://www.nxtbook.com/nxtbooks/aas/st_202010
https://www.nxtbook.com/nxtbooks/aas/st_202009
https://www.nxtbook.com/nxtbooks/aas/st_202008
https://www.nxtbook.com/nxtbooks/aas/st_202007
https://www.nxtbook.com/nxtbooks/aas/st_202006
https://www.nxtbook.com/nxtbooks/aas/st_202005
https://www.nxtbook.com/nxtbooks/aas/st_202004
https://www.nxtbook.com/nxtbooks/aas/st_202003
https://www.nxtbook.com/nxtbooks/aas/st_202002
https://www.nxtbook.com/nxtbooks/aas/st_202001
https://www.nxtbook.com/nxtbooks/aas/st_201912
https://www.nxtbook.com/nxtbooks/aas/st_201911
https://www.nxtbook.com/nxtbooks/aas/st_201910
https://www.nxtbook.com/nxtbooks/aas/st_201909
https://www.nxtbook.com/nxtbooks/aas/st_201908
https://www.nxtbook.com/nxtbooks/aas/st_201907
https://www.nxtbook.com/nxtbooks/aas/st_201906
https://www.nxtbook.com/nxtbooks/aas/st_201905
https://www.nxtbook.com/nxtbooks/aas/st_201904
https://www.nxtbook.com/nxtbooks/aas/st_201903
https://www.nxtbook.com/nxtbooks/aas/st_201902
https://www.nxtbook.com/nxtbooks/aas/st_201901
https://www.nxtbook.com/nxtbooks/aas/st_201812
https://www.nxtbook.com/nxtbooks/aas/st_201811
https://www.nxtbook.com/nxtbooks/aas/st_201810
https://www.nxtbook.com/nxtbooks/aas/st_201809
https://www.nxtbook.com/nxtbooks/aas/st_201808
https://www.nxtbook.com/nxtbooks/aas/st_201807
https://www.nxtbook.com/nxtbooks/aas/st_201806
https://www.nxtbook.com/nxtbooks/aas/st_201805
https://www.nxtbook.com/nxtbooks/aas/st_201804
https://www.nxtbook.com/nxtbooks/aas/st_201803
https://www.nxtbook.com/nxtbooks/aas/st_201802
https://www.nxtbook.com/nxtbooks/aas/st_201801
https://www.nxtbook.com/nxtbooks/aas/st_201712
https://www.nxtbook.com/nxtbooks/aas/st_201711
https://www.nxtbook.com/nxtbooks/aas/st_201710
https://www.nxtbook.com/nxtbooks/aas/st_201709
https://www.nxtbook.com/nxtbooks/aas/st_201708
https://www.nxtbook.com/nxtbooks/aas/st_201707
https://www.nxtbook.com/nxtbooks/aas/st_201706
https://www.nxtbook.com/nxtbooks/aas/st_201705
https://www.nxtbook.com/nxtbooks/aas/st_201704
https://www.nxtbook.com/nxtbooks/aas/st_201703
https://www.nxtbook.com/nxtbooks/aas/st_201702
https://www.nxtbook.com/nxtbooks/aas/st_201701
https://www.nxtbook.com/nxtbooks/aas/st_201612
https://www.nxtbook.com/nxtbooks/aas/st_201611
https://www.nxtbook.com/nxtbooks/aas/st_201610
https://www.nxtbook.com/nxtbooks/aas/st_201609
https://www.nxtbook.com/nxtbooks/aas/st_201608
https://www.nxtbook.com/nxtbooks/aas/st_201607
https://www.nxtbook.com/nxtbooks/aas/st_201606
https://www.nxtbook.com/nxtbooks/aas/st_201605
https://www.nxtbook.com/nxtbooks/aas/st_201604
https://www.nxtbook.com/nxtbooks/aas/st_201603
https://www.nxtbook.com/nxtbooks/aas/st_201602
https://www.nxtbook.com/nxtbooks/aas/st_201601
https://www.nxtbook.com/nxtbooks/aas/st_201512
https://www.nxtbook.com/nxtbooks/aas/st_201511
https://www.nxtbook.com/nxtbooks/aas/st_201510
https://www.nxtbook.com/nxtbooks/aas/st_201509
https://www.nxtbook.com/nxtbooks/aas/st_201508
https://www.nxtbook.com/nxtbooks/aas/st_201507
https://www.nxtbook.com/nxtbooks/aas/st_201506
https://www.nxtbook.com/nxtbooks/aas/st_201505
https://www.nxtbook.com/nxtbooks/aas/st_201504
https://www.nxtbook.com/nxtbooks/aas/st_201503
https://www.nxtbook.com/nxtbooks/aas/st_201502
https://www.nxtbook.com/nxtbooks/aas/st_201501
https://www.nxtbook.com/nxtbooks/aas/st_201412
https://www.nxtbook.com/nxtbooks/aas/st_201411
https://www.nxtbook.com/nxtbooks/aas/st_201410
https://www.nxtbook.com/nxtbooks/aas/st_201409
https://www.nxtbook.com/nxtbooks/aas/st_201408
https://www.nxtbook.com/nxtbooks/aas/st_201407
https://www.nxtbook.com/nxtbooks/aas/st_201406
https://www.nxtbook.com/nxtbooks/aas/st_mars
https://www.nxtbook.com/nxtbooks/aas/st_201405
https://www.nxtbook.com/nxtbooks/aas/st_201404
https://www.nxtbook.com/nxtbooks/aas/st_201403
https://www.nxtbook.com/nxtbooks/aas/st_201402
https://www.nxtbook.com/nxtbooks/aas/st_201401
https://www.nxtbook.com/nxtbooks/aas/st_201312
https://www.nxtbook.com/nxtbooks/aas/st_201311
https://www.nxtbook.com/nxtbooks/aas/st_201310
https://www.nxtbook.com/nxtbooks/aas/st_201309
https://www.nxtbook.com/nxtbooks/aas/st_201308
https://www.nxtbook.com/nxtbooks/aas/st_201307
https://www.nxtbook.com/nxtbooks/aas/st_201306
https://www.nxtbook.com/nxtbooks/aas/st_201305
https://www.nxtbook.com/nxtbooks/aas/st_201304
https://www.nxtbook.com/nxtbooks/aas/st_201303
https://www.nxtbook.com/nxtbooks/aas/st_201302
https://www.nxtbook.com/nxtbooks/aas/st_201301
https://www.nxtbook.com/nxtbooks/aas/st_201212
https://www.nxtbook.com/nxtbooks/aas/st_201211
https://www.nxtbook.com/nxtbooks/aas/st_201210
https://www.nxtbook.com/nxtbooks/aas/st_201209
https://www.nxtbook.com/nxtbooks/aas/st_201208
https://www.nxtbook.com/nxtbooks/aas/st_201207
https://www.nxtbook.com/nxtbooks/aas/st_201206
https://www.nxtbook.com/nxtbooks/aas/st_201205
https://www.nxtbook.com/nxtbooks/aas/st_201204
https://www.nxtbook.com/nxtbooks/aas/st_201203
https://www.nxtbook.com/nxtbooks/aas/st_201202
https://www.nxtbook.com/nxtbooks/aas/st_201201
https://www.nxtbook.com/nxtbooks/aas/st_201112
https://www.nxtbook.com/nxtbooks/aas/st_201111
https://www.nxtbook.com/nxtbooks/aas/st_201110
https://www.nxtbook.com/nxtbooks/aas/st_201109
https://www.nxtbook.com/nxtbooks/aas/st_201108
https://www.nxtbook.com/nxtbooks/aas/st_201107
https://www.nxtbook.com/nxtbooks/aas/st_201106
https://www.nxtbook.com/nxtbooks/aas/st_201105
https://www.nxtbook.com/nxtbooks/aas/st_201104
https://www.nxtbook.com/nxtbooks/aas/st_201103
https://www.nxtbook.com/nxtbooks/aas/st_201102
https://www.nxtbook.com/nxtbooks/aas/st_201101
https://www.nxtbook.com/nxtbooks/aas/st_201012
https://www.nxtbook.com/nxtbooks/aas/st_201011
https://www.nxtbook.com/nxtbooks/aas/st_201010
https://www.nxtbook.com/nxtbooks/aas/st_201009
https://www.nxtbook.com/nxtbooks/aas/st_201008
https://www.nxtbook.com/nxtbooks/aas/st_201007
https://www.nxtbook.com/nxtbooks/aas/st_201006
https://www.nxtbook.com/nxtbooks/aas/st_201005
https://www.nxtbook.com/nxtbooks/aas/st_201004
https://www.nxtbook.com/nxtbooks/aas/st_201003
https://www.nxtbook.com/nxtbooks/aas/st_201002
https://www.nxtbook.com/nxtbooks/aas/st_201001
https://www.nxtbookmedia.com