Progress on my telescope’s mount

Despite the lack of any progress updates here in awhile, I actually have been slowly working on my telescope. I’ve merely been slowing down because my attention has been diverted by other things (like amateur radio and other miscellaneous projects I haven’t bothered blogging about). So here’s an update on my latest progress. I haven’t touched the mirror since the last update, but I’ve made a bit of progress on the mount. Enjoy the pictures.

PVC clamped onto cradle

The cradle (wooden box) has internal dimensions of just a hair over 10.5″, so the telescope tube can slide in it. It’s 14″ long. Here, I have a section of 10″ PVC pipe clamped to it in preparation for tracing its outline. The PVC section will be what rotates the cradle up and down, providing altitude control.

Routing path on cradle outlined

Here’s the cradle with the outline of the PVC section traced out in preparation for routing the circle. This will allow me to more easily affix the PVC section to the cradle, and ensure that it doesn’t go anywhere. Another circle is traced out on the opposite side.

Side of cradle after routing

The cradle after the circle has been routed out (by hand, no fancy central-pivot system or anything). In case you’re unfamiliar, a router is a device somewhat like a drill that allows cutting to a controlled depth and continues cutting during lateral movement. Making it move in a circle isn’t very easy.

Cradle with PVC section embedded

Proof that the PVC section actually does fit into the routed out circle. Because neither the circle nor the PVC pipe are perfect, it actually takes a bit of rotating and squeezing the PVC section to get it in there, and once it is in there, it sticks in pretty good. Finding a permanent way to attach it won’t be too difficult.

Tracing out circle for cradle rest

Using the PVC section to trace out its outline on the top of one of the side pieces. This is what the PVC section will rotate in, providing altitude adjustment.

Traced circle for cradle rest

The final trace that I would begin cutting one. Notice that one of the two curves (the smaller one) is pretty much superfluous.

Rough-cut cradle holding PVC segment in place

One of the sides after my first rough cut with the router (admittedly maybe not the best tool for this). You can see that it’s too tight because it’s managing to hold the otherwise unsupported PVC section in place. During the fine cut, I expanded the circle a little bit. It didn’t matter too much that it be perfect, because as you’ll soon see, the PVC section only makes contact with it in two places.

Tracing one cradle rest out of another

Tracing the outline of the final shape onto the other side piece in preparation for cutting it.

Countersinking the teflon pads

The four Teflon pads after countersinking. A countersink is a special drill bit designed to cut out enough material for the top of a screw to nestle comfortably in. The countersinking in this step is essential, because otherwise the PVC section would be scraping up against the screws as it rotated. Note that screwing in the Teflon is pretty much the only option available; gluing it obviously doesn’t work.

The teflon pads are attached

Two of the Teflon pads attached to one of the side pieces. I confirmed that the PVC segment does indeed rotate in it smoothly.

That’s all of the pictures I have for now. Not included in these pictures is the work I did last night: I stained all of the pieces of wood you saw above with a nice Minwax PolyShades stain which simultaneously makes the wood darker in color and seals it with polyurethane for nice weather protection. Now all I have left to do on the mount is to permanently secure the PVC sections to the cradle, assemble the four sections of the main body, construct the azimuth mount for the bottom of the base (which consists of a disc of plywood with feet on the bottom and Teflon pads on the top that the base rotates on), and attach handles to both sections for easier transportation. Oh, and I have to assemble the optics in the tube, which I’ll hopefully do on Friday night.

2 Responses to “Progress on my telescope’s mount”

  1. Guy Brandenburg Says:

    Looks good! Keep it up!
    Guy

  2. luis Says:

    how can I contact the guys from the shop?I live in rockville and tonigth beside that I’ve learned a lot reading your lines I have found very intresting all this about the telescope.I want to know more about it.I hope you have the chance to finish your project….looks really good!!!!!!!!!!!!!