One of the wonders of building such a precise astronomical insturment is how roughly some of the tools and equipment can be built. Our stand is largely built from scronged items that I already had on hand. Before the kids and I went to Lowe's I took stock of what I already had, so that I could get by as cheaply as possible.
When we got to the store, we went straight to the plumbing department. I really wanted to get a galvanized pipe and flange for the pedastal, but I didn't want to spend as much as that was going to require. My next choice was oak, but again price intervened. Ultimately, I decided on the PVC which cost less than $7.
The first step was to cut a 6" 4x4 timber (it had been a part of a fence that I took down). We then planed the corners off so that it would fit inside the PVC pipe. This timber is what the top is secured to. We then mixed a bag and a half of mortar mix left over from my oven project. It had set around for nearly a year and become quite compacted.
Once the mortar was mixed, we filled the bucket with the mortar and then set the pipe in, which we also filled leaving room for the 4x4 block. We used a level to make sure everything was properly plumbed and leveled. All of the weight makes the stand very stable, so that it will not be wobbly when we begin grinding.
I then attached the top using 4 counter-sunk screws, which can be seen through the mirror blank. The cleats, which hold the mirror, is from a flower stake from my garden. The cleat screws are also counter-sunk.
The only thing left to do with the stand is to seal the top. When using the abrasive charges for grinding, water is used as a lubricant, and I am sure that the glue used in the top is not waterproof.
We will using Kilz, left over from painting the bathroom for the sealer. Once that is done, our stand will be completed.
Also, the mortar does not adhere to the PVC, so there is no need to be excessively careful when filling the PVC pipe.
When doing a project like this, do not be afraid to use what you have on hand. Remember the goal is not a beautiful stand, but one that is serviceable for the intended use.
Next week, we will begin "hogging out" the mirror blank and making the grinding tool. Stay tuned.
can't wait to find out what "hogging out" means---sounds like something to do with food... :)
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