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ATM Parts

Secondary Mirrors

We sell premium secondary mirrors in the most popular sizes. All are made on fused Quartz ®, 1/10 wave or better. Includes interferogram test data. All have 96% enhanced coatings. These are the finest secondary mirrors available anywhere.

Secondary mirrors are 1/10 wave from Ostahowski Optics and have 96% Brilliant-Diamond coating. Secondary mirrors can be purchased separately. These are simply the finest optics and coatings available anywhere.

2.6" $325

3.1" $475

3.5" $525


Side Bearings

Solid cast aluminum side bearings

Note: You supply the laminate of your choice.

18.5 inch diameter arcs
(used on Obsession 12.5 inch scopes)
$95 per pair plus $25 shipping

20.5 inch diameter arcs
(used on Obsession 15 inch scopes)
$285 per pair plus $50 shipping

24 inch diameter arcs
(used on Obsession 18 inch scopes)
$325 per pair plus $60 shipping

26 inch diameter (with spokes)
(used on Obsession 20 inch scopes)
$375 per pair plus $70 shipping

Side Bearings

Etched Virgin Teflon


Same Teflon used on all Obsessions. 0.093 thickness. Acid etched on one side so it will accept an adhesive like contact cement or epoxy. No nails needed. Sold only in 6 x 12 inch sizes. Score with a sharp knife on the back side and it breaks into perfect pieces.

$85 plus $11 shipping.

Primary Mirror Collimation Bolts

split bolt

3” long with 3/8” threads. Same collimation bolts we use on all our production telescopes.

$12 set of three. plus $10 shipping. $22 total for domestic destinations.

Aluminum Tubing for Truss Poles

split bolt

We offer aluminum tube in the most popular sizes. This is the same 6061 aluminum tube we use for all our truss poles. Available in lengths up to 12 feet. In stock. 4 foot minimum.

Email or call for quote. Specify size, length, and amount.

1.25" OD - 049 wall $5.25 per foot

1.50" OD - 049 wall $5.75 per foot

Tube Inserts

tube inserts

Threaded push fit tube inserts

Press fit into the ends of aluminum tubing, they allow you to connect the wood cage rings to the struts.

For 1.0 and 1.25 inch diameter tube only. Sorry no other sizes for sale.

$3 per insert plus $11 shipping for any quantity to any US destination.

Split Bolts

split bolt

1/2" by 4" long machine bolt has a 2" long water jet cut slot in it. The end of the bolt is not cut so it has far more strength. Insert your sling through the slot. This heavy duty slotted bolt will hold even the heaviest mirrors up to 30 inches. No need to hack saw anything.

$60 per pair plus $11 shipping ($71 total) to any US destination.

Kevlar Mirror Sling

split bolt

1.5" wide Kevlar sling webbing is the same fabric we use on our Classic series. No stretch and rated for 2000 pounds, this material will hold any primary mirror. Pass it through your split bolts and you have the perfect edge support.

$3 per foot

Argo Navis™ Digital Setting Circles

Argo Navis remote

The "Argo Navis™ digital setting circles" are the most advanced DSC in the world. Now you can have over 29,000 object at your finger tips, flash memory, highest navigational accuracy and much much more. It even corrects for mount errors and atmospheric diffraction! With the Argo Navis™ you will target and observe ten times as many objects during the night than with a traditional finder.

We are an Argo Navis™ dealer and usually have the Argo Navis and super 10K res encoders in stock.

"The Dobsonian Telescope"

"The Dobsonian Telescope"

By Kriege and Berry

Highly recommended for all Dob builders.

Save hundreds of dollars and learn how to build the best scope possible.

"It belongs on the shelf of every amateur telescope maker, and for that matter every Dobsonian owner. With its whimsical style and thorough treatment of the subject the book is destined to become a classic...
"Sky and Telescope, October 1998

Ordering Info

Sorry we are not set up for credit cards. To order, please send a check to cover the total amount plus shipping (US destinations only) to:

PO BOX 804

If you have any ordering questions please send an email. NOTE, foreign orders (outside United States) please send an email so we can determine shipping costs before you place your order.