Takahashi PM Mounts Ready for Autoguiding

Unfortunately, Takahashi PM series mounts have no autoguider port. Personally I don’t feel the needs of autoguiding since tracking and polar scope accuracy are good enough for my use – mainly 200 – 300 mm focal length in each 3 minute exposure. But the dithering must be nice.

Here is the retrofit solution.

_DSF1002Some of ST-4 wires are soldered directly onto PCB and connected to Shoestring GPUSB to electrically isolate. I tested with BORG guide scope with ZWO174MM last night. It just worked as expected. The retrofit work shouldn’t be challenging to all of users. So we will write up the procedure of that. But at least you need to get a Shoestring autoguider interface box.

I was using PhD guiding for the test.  Believe or not, this was my 1st attempt for this software. I don’t use PC at the field. So I needed a bit the time to go along with it. PhD guiding log looked describing within +/- 2 arc seconds for RA tracking if my reading was correct. And as expected, DEC was no shifting in 5 minutes. This reminded me how Takahashi polar scope was accurate. That actually looked similar performance to my EM200. Factory-installed EM200’s polar scope always allows for no DEC correction even without the drift alignment or some other fine-tuning method. An optical scope is accurate enough. Period. This PM series showed similar to that. As always, I feel this is real good value. This assured me I won’t need any other extra device such as PoleMaster etc for PM mounts either.

Anyway, I understand many of Takahashi PM users are interested in autoguiding capability. Until the procedure will be up online, please contact me for further details. I will send you a picture where each wire should be soldered. Fortunately, controller box already has the good size of clearance hole at rear side. So as shown above picture, the cable can go through without any modification work.

Also I wanted to mention PM-1’s one of very good features is two levers.

I’m sure these levels help for accurate polar alignment a lot. While I’m using PM-1 mount myself, I’m sure this is the mount Takahashi technical staff carefully and seriously designed. Probably I can say this is the ultimate portable mount.

Above setup shows PM-SP(a smaller brother) counterweight and shaft. But heavy equipment users can set an PM-1 original shaft and weight. Originally it was not intended for that. But I noticed the reversed shaft fits as follows


Then, we can set 5 – 6 kg equipment at the top.



~ by tedishikawa on July 16, 2016.

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