By: Public Missiles Ltd.

Contact 1-888-PUBLIC-M

Large carbon fiber tubes available in diameters up to 24"!
Carbon fiber is a simple and effective imaging solution.

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Carbon Tube and Dew Shield on C-14

About Our Carbon Tubes...

Aerospace Quality Materials
All of our tubes are made from the highest quality PAN based carbon fiber available. Also, we do not use "seconds" or "blems" found at surplus sites on the net. This is first-quality, aerospace certified material direct from the (USA) manufacturer.

Tube Construction
The carbon fiber is compression wrapped in a hi-temp epoxy matrix and cured at 160 degrees over a precision mandrel. The OD of the tube is epoxy coated and precision ground before urethane clear-coating and polishing. The tube is cut to length while still on the mandrel to assure squareness. Tube OD tolerance can be held to +/- 0.010" even on our largest diameters. Wall thickness can be held to +/- 0.005".

Urethane Clear-Coat Finish
Our Premium carbon fiber tubes are clear-coated with two-part, automotive grade urethane. The clear-coat is baked at 150 degrees to full cure before it is polished to a mirror finish.
The particular clear-coat we use has very good UV blocking agents to greatly reduce the degrading effects that UV radiation has on the epoxy resin.
Be wary of any tube that does not have UV protection, they will begin to yellow very quickly and will eventually begin to degrade.
More About Our Tubes
Stay focused.
Lose weight.
Look great! .
Carbon tube close-up
How would a carbon fiber tube help me with imaging?

The answer is simple... As the temperature drops, your aluminum OTA tube is shrinking! This brings the primary and secondary closer together and moves your focal plane off the surface of your imaging chip. With a typical SCT, moving the mirrors by 0.001" can move the focal plane by as much as 0.025"! The result is a blurry image.

Our goal is also simple... To provide you with a large diameter carbon fiber tube that does not shrink nearly as much as an aluminum or even steel tube thus making your imaging time much more productive and less frustrating.

We are not claiming that carbon fiber tubes don't shrink at all as the temperature drops, they do. However, our carbon fiber tube shrink rate is at least 1/5th that of aluminum. This means you can image 5 times as long between focus runs! If you could image for an hour without re-focusing with your aluminum tube, now you can image for 5 hours between focus runs.*

*Please note that each night is different and each night the temperature changes will vary. Also note that in most cases you will still need to re-focus when changing filters.

Our Carbon Fiber Tube upgrades will help you.....

Stay Focused
Carbon fiber has vastly superior thermal expansion properties over aluminum. With a typical aluminum C-11, you need to refocus for every 1.5 to 2 degrees of temperature drop. Since the C-14 uses a longer tube, the effect is even greater. If you are shooting 10, 15, or even 20 minute exposures, you can stop after a few exposures and re-focus. This constant re-focusing can be bothersome and eats away at your actual imaging time. The effect is much worse when shooting very long (1-2 hour) exposures in narrow band since you can't stop and re-focus during the exposure. So most nights you simply can't shoot that long because your focus will change by the time a single exposure is completed.

With a carbon tube, you can easily go 10 degrees without refocusing. During a typical Michigan night, the temperature can easily drop 2 degrees per hour. Hence, Ha exposures over 45 minutes were impossible. Now I can image most of the night without re-focusing. Take a look at the M-27 image I posted below. It is a series of 60 minute H-alpha sub exposures (plus RGB). I now consider the 60 minute Ha sub-exposures "short" and typically go with 90 and 120 minute subs. This was impossible for me without the carbon fiber tube upgrade.

Lose Weight
Carbon fiber typically saves 40% in weight over a similar aluminum tube. Weight is not as much of a factor with a typical SCT but it makes a huge difference with longer tubes such as an RC, and especially Newtonian or Classical Cass. Of course, if you are already pushing your mount (or your back!) to the limit, saving 3 lbs. on a C-14 is a good thing!

Look Great!
Nothing has a better "wow factor" than a finely finished carbon fiber tube. Up close, it looks like a hi-tech 3D snake skin with amazing depth. When someone sees your carbon scope, they will know you are serious about the quality of your equipment.

M-27 nebula image
Image of M-27 by: Frank R Uroda