What is an SCT Cooler?

UPDATE FEB 1, 2023: Prices have changed to reflect increasing component and shipping costs.  8-11" models are now $109.95 plus $15.00 added for shipping in the 48 states.  The price of 12 - 14 models are now $129.95 plus $20.00 added for shipping in the 48 states.  Shipping outside the 48 states will be quoted once we receive your complete shipping address.



We have been quietly shipping the NEW SCT Cooler to select customers for the last few months. The reception has been excellent.   An example email from an early adopter / beta tester:


From: Dean Devera [mailto:dean.devera@XXXXX.XXX]

Sent: Saturday, December 19, 2015 10:31 AM


To: Robert Haler

Subject: Re: Do you still carry SCT coolers?


Hi Robert,


I finally had a chance to use the new cooler over the past few

days.  It's awesome!  Last night, I was finally able to see the

'E' and 'F' Trapezium stars in M42.  I'd never been able to do

this before using active cooling, even on nights of good seeing.

I'm certain the Lymax helped make it possible.  I love this thing,

and I'm sure the new design will be a hit!!


Hope you have a happy holiday season and new year!!



Dean Devera



What's New About the R3 SCT Cooler?


  • The main body is now 3D printed
  • Lower cost - Only $109.95 for 11" and smaller and $129.95 for 12-14", plus shipping of $15.00  for 11" and smaller in the 48 states; $20.00 shipping for 12-14" in  the 48 states
  • Half the weight of the previous version
  • Runs from USB port power - use your cell's backup battery pack!
  • Filters, blowers, and air ducts can be customized for special applications
  • Custom versions and odd sizes are available.


Why the change when everybody loved the R2?   Short version:


They were getting prohibitively expensive to produce and new telescopes require flexibility of design.


Like many important accessories astronomers have come to depend on, the SCT Cooler is a steady demand, but relatively low-volume product. Anybody in the business of manufacturing will tell you: volume is everything. It controls your costs, access to raw materials, access to skilled labor, etc. It is not economically or logistically practical to make these in huge quantities and then store those huge quantities for extended periods. The price of plastic keeps going up (allegedly because the price of oil keeps going up, but it never comes down when the price of oil goes down!)  The  cost per hour for using a $1M 5-axis CNC mill keeps going up; and getting a production slot scheduled is becoming harder. Many common components - like mechanical switches, large connectors, and discrete leaded LEDs are becoming obsolete.  This is driven by regular progress - like touch technology; or being pushed out by social pressure - like the once ubiquitous cigarette lighter plug.  By moving to 3D printing, we are able to reduce our costs and the retail price. We also get incredible flexibility in being able to produce special models and models for unique telescopes.


A FAQ, more images, movies of SCT coolers being printed, and the full story of "How the SCT Cooler is a case study in how 3D printing can save a product from oblivion" will be published shortly.



To Purchase an SCT Cooler:


Email lesa@lymax.com with your PayPal address and the size of telescope for which you require a cooler.  We currently have coolers sized for Celestron 8", 9.25", 11", and 14" SCTs and Meade 8", 10", 12" and 14" SCTs.  We can also accommodate other sizes of SCTs, MAKs, and other brands of scopes.  Just email us your requirements and we send you back the measurements we need.


Your scope MUST have NO LENSES IN THE BAFFLE TUBE OR FOCUSER. The air duct fits inside the optical tube via the focuser.


You will be sent an invoice via PayPal by lymaxstore@lymax.com


All SCT Coolers are made to order to keep costs down and accommodate special requirements.  Our current lead time to shipment is 2 weeks after payment is received.


We accept all payments through PayPal. If you do not have a PayPal account, you can still pay us via PayPal using a credit card.  Email us with your requirements and mention that you don't have a PayPal account. We will email back instructions.


International Customers:  We will need your full shipping address to quote shipping costs.  A contact phone number will also be required for completion of the shipping and customs documents.  Customer is responsible for any customs fees or duties imposed by your respective authorities.


Your Questions are welcome!



Our ebay store is still open!

take me to Lymax's ebay store

CosmicOne SCT Cooler model R3 by Lymax

The CosmicOne SCT Cooler - or "Cat Cooler" - is a device for ventilating the inside of SCTs, Maks, and other catadioptric telescopes so that they may be brought quickly to ambient temperature.  This allows image-ruining tube currents and heat pillars to be minimized in 10-20 minutes instead of the usual 45 minutes to 2 hours.  The greater the temperature difference between the place your telescope is stored and the outside evening air, the more quality viewing time you can reclaim with a CosmicOne SCT Cooler.  The SCT Cooler has a filtered air intake and other design features which minimize the possibility of dust infiltration and direct the air flow away from the internal optical surfaces.  SCT Coolers are available exclusively from Lymax!

The original R1 Model of the CosmicOne SCT Cooler by Lymax