One of these days I will have to start doing portable satellite operations. I found this project on the SARCNET website and decided to adapt it to my needs. I have very little experience with mechanical constructions (especially using metals), so their complete design for their MK-II rotator was a great guidance.
I could have bought these bearings locally, but when doing research on the web I found that Banggood had both the bearings and motors + controllers, so I bought all in one go.
The pillow block bearing with 25mm bore was US$5.09.
The flange bearings, also with 25mm bore were US$6.96 per piece and I ordered three of them.
The DC motors were also bought from Banggood. They're 12V 2RPM Reversible High Torque Turbo Worm Geared DC Motors and they were US$9.87 each.
These were especially made for me by a local business in the next town of Zhongli. The chain is type 25 and the big sprockets are 25x32 with a 1" bore, the smaller ones 25*10 with a 6mm bore. I chose a 1" bore for the bigger ones because at the time I didn't know if I could find 25mm tubing. With a shim made of an old can they will fit 25mm tubing just fine.
I paid NT$200 for the 25*32 sprockets per piece, so US$13.5 in total.
The 25*10 sprockets were NT$140 per piece, so US$9.50 in total.
Ten feet of type 25 chain was NT$200, so US$6.50.
In total, with tax, I paid US$31.00.
This were the trickiest parts to get. It was impossible to get 25.0mm tubing of any kind (alu, stainless, fiberglass), so in the end I got these two 60 cm pieces of alu-tubing with an 8mm inner diameter and 25.4mm outer diameter. With the help of BX2AB I found a metal workshop where they could be machined down to 25.0mm. The added cost of that was staggering: NT$500 per piece of tubing (US$16.50). Luckily I didn't have that much money on me when I collected them and the owner was in a good mood, so I emptied my wallet and only payed NT$600 for both of them (US$20), because that's what I had.
Cost of the material: 2x NT$250 (US$16.50 in total).
Labor cost: NT$600 (US$20)