DIY polarscope illuminator

[Clive]

Having recently purchased a SW EQM-35, on first use I was disappointed to find that the polarscope was next to useless since the graticule was completely invisible.  For the first 3 uses (only 3 clear nights since it arrived in mid-September) I used PHD2 drift alignment to home in on the pole but I seemed to be spending more time on alignment that actually imaging.

 

The polarscope hole in the EQM-35 is just the right size for 32mm plastic waste pipe, so in the intervening cloudy period, I put together this polarscope illuminator.  Since I use a USB hub at the mount, it seemed sensible to use one of the spare ports for the power.  Apart from the pipe, insulating tape, super glue (used to bond the cables to the pipe and box) and the USB cable, all of which I already had at home, the parts were purchased from Farnell for just over £5.

 

Last night was the first clear night for weeks so I had the opportunity to try it out.  Setting Polaris to the correct position on the graticule was a breeze and done in a minute or two.  It's surprising how little light is required to see the graticule.  The circuit shown allows the LED to be completely turned off, whilst at maximum intensity, Polaris is completely hidden.  I found that about 1/3 of a turn from minimum gave the ideal illumination level.

 

 

[Philip Gray]

Hi Clive, you have inspired me to follow suit!

 

I just bought the EQM-35 and was about to take the plunge and buy the polar illuminator when Google led me to you

 

I'm up in the North East of Scotland - Kemnay in Aberdeenshire 

 

No real experience of electronic assembly but keen to start - soldering iron at the ready and 3D printer on standby 🙂

 

One quick question - when you're gathering components for these kinds of projects are you sourcing individually or do you buy bulk/starter kits - I'm assuming such things might be available

 

Phil

[Clive]

2 hours ago, Philip Gray said:

Hi Clive, you have inspired me to follow suit!

 

I just bought the EQM-35 and was about to take the plunge and buy the polar illuminator when Google led me to you

 

I'm up in the North East of Scotland - Kemnay in Aberdeenshire 

 

No real experience of electronic assembly but keen to start - soldering iron at the ready and 3D printer on standby 🙂

 

One quick question - when you're gathering components for these kinds of projects are you sourcing individually or do you buy bulk/starter kits - I'm assuming such things might be available

 

Phil

Hi Phil, I generally purchase my electronic bits and bobs as required from Farnell (https://uk.farnell.com/). You could probably get things cheaper elsewhere but I've used them for years and their is full part data available so you know exactly what you are buying. If you put the part numbers I quoted into the Farnell website search box it should take you to the exact part that I used.