CONSTRUCTION OF 4-1/4" F4 AND 10" F4 NEWTONIAN REFLECTORS

I decided to upgrade my main telescope back in 2009. And since I'm primarly interested in CCD imaging, optical quality was very important - as was keeping the costs down/wife happy. After some research around the web, I settled on a quite reasonably priced primary mirror from Bob Royce. He offers light-weight conical mirrors and I felt that a fast (F4) 10" mirror in combination with a carbon fiber tube would give me an all around excellent telescope.

The 4-1/4" F4 Newtonian
Since I already had an old set of Edmund Scientific mirrors laying around, I decided to make a carbon fiber tube for a smaller telescope first to get the feel for working with the materials. Most of the cost was in the JMI 1-1/4" Crayford focuser. I made the mirror cell and spider from materials I had on hand. I purchased a bit of aluminum and machined from it the telescope tube end rings and mounting rings. This ended up being a complete success and I plan to use this telescope for visual and/or wide field CCD imaging. The process of making the CF tube is as described below for the 10" F4 'scope.

The 10" F4 Newtonian
I purchased the conical primary mirror from Bob Royce and the secondary/spider from Protostar. The mirror cell is epoxy coated plywood and the focuser is a JMI 2" Crayford. Total weight is 19.5 lbs (OTA only, without finder and cradle). A fine telescope that optically blows away the old 8" Meade SCT. The 41"L x 13-3/8"OD laminated carbon fiber tube has end rings made from simple/cheap rubber stripping, they look nice and protect the tube. The tube is very strong and needs no additional support from metal end rings.
Fabrication of the tube was as follows... I made the tube myself from materials purchased from Aircraft Spruce. I followed the safety instructions for all of this stuff! This was an outside/well ventilated area job. Glass micro is dangerous (I kept it out of my eyes/lungs)! The epoxy is dangerous (I read the warning labels)! Tiny CF particles can get into the air when cutting/drilling (I kept them out of my eyes/lungs). I used safety glasses and an expensive filter mask made for this type of application! The CF fabric was available in a 42" width so there was very little waste and the tube ended up costing about the same as an aluminum one would have. I used a 12" OD cardboard concrete form covered in Instapak plastic film. The ezpoxy absolutely does not stick to that stuff. Did two wraps of CF followed by a 1/2" foam core followed by three wraps of CF. I scored the foam every 1" with a utility knif as it wouldn't "bend" around anything near a 12" OD. I just made up a jig to hold/spin the cardboard tube and wrapped the CF around it while wetting the fabric thoroughly in epoxy with a Plastic Squegee. When the time came to do the foam core I mixed a generous amount of glass micro with the epoxy (think pancake batter) to aid it's bonding to the CF then finished with the three wraps of CF on top of the foam. I bought peel-ply, but didn't use it - and no vacuum bagging either. After a couple of days dry time, I cut/peeled/ripped the concrete form out of the tube. Finally, I clear coated the outside of it for UV protection and sprayed the inside with flat black paint.