There are a few "homemade pipe mount" threads in the ATM forum but I'll add to this thread here too.
I built two pipe mounts out of 2" black pipe. An equatorial mount and an alt-az mount. The alt-az mount can hold two scopes or be converted to hold one scope with counterweights on the opposite side.
I also built the pier. The pandemic, lack of available lumber, having COVID-19, and a TBI have delayed building the observatory and fencing that will surround this pier. I hope to get to finishing the observatory this summer assuming lumber becomes available again in my neck of the woods (I hope so because I now have a long list of projects on my to-do list).
We have bears, bobcats and skunks roaming through the yard every night in the warmer months so having a secure area for observing/imaging is absolutely necessary. This new pier has only been useful for solar observing so far because it is out in the open which leaves me vulnerable to wildlife. I find it impossible to stay focused on what I am doing when I am constantly looking around and over my shoulder all the time. I had one scare with a bear and I have no desire to ever experience that again. No hobby is worth that.