SharpSky ASCOM compliant digital focuser project

[wasyoungonce (Brendan)]

Dave and users, a few observations on the controller kit. These are some points I have experienced and are not necessarily criticisms but more things to watch for. In any case constructive criticisms are good...brings about constructive change and I know you are a pro-active person generally more than one-step ahead!:

1. The power PCB jack is 2.1mm centre +ve. I stick to 2.5mm centre ....mixing sizes can be a real pain in the field...especially if you fit a 2.5 centre plug in a 2.1 jack...you get intermittent power drop-outs. It's not an issue using 2.1mm however if you want 2.5mm they can easily/cheaply be changed prior to install....it's just users should be aware of this. We all have out favourite sizes and we all differ.

2. The PCB DC jack is recessed in the case (as are all connectors apart from the the motor DB9) so you need to bore a wide enough hole so the the power plug fits thru the case to the jack. The PCB power jack is designed for a 10mm shaft connectors...but...you can get these connectors in 14mm shafts! Thus if you use a longer 14mm power plug shaft (see here and here) you do not need to bore the power jack hole so wide...just to fit thru the case!

3. I found you need to bore the temp and hand controller mini DIN holes in the case larger than mentioned. I found the case walls are at a slight angle and to allow straight plug entry you may need 13~14mm holes.

4. I found the supplied LED clips distorted when the LED's were fitted, I had some Jaycar 3mm LED clips that worked better. I also needed to bore the clip holes larger than the 4mm.

5. I have had issues with the fly LED PCB holes. I damaged a few fly leads when testing (broke off the fly leads) un-soldering the left overs was a real pain and I damaged one via, obviously my fault! I couldn't solder wick (with flux) out the remaining solder so I had to bore the holes with a .6mm drill and this damaged the hole via feed thru. This is not a design fault just clumsy hands.....but..in light of that I would really like a header and plug system for these LEDs instead of the current system. Yes I know the constraints of size and height (for the case design) but maybe a small header/plug (not the std 2.54 size SIL) ...I've seen on fleabay....somewhere?

6. Mounting....obviously as with most DIY mounting is a thing you work out yourself. I have designed stuff and had the same attitude. However, I found the flanged lid version of the case allows itself to mounting better than the original case, see above pics. If you want to replace the case then element 14 has cheap flanged lid cases (here).

The above is not a name a shame it's just things I experienced in building the controller that others may come across. Oh, I'm anal when doing things like this (due to my background) so what I say may be frivolous to many!

Might I say..."Damn this system works well".......keep up the good work Dave, I'm a devoted fan and you know we speak similar language.

[dtrewren (Dave)]

Hi Brendan et al,

That's cool I like the feedback because as you say it allows things to be updated for the better. Here is some feedback on your points :

1. Good point regarding the 2.1mm power sockets. I actually have a pile of 2.5mm sockets here so if anyone fancies swapping over I can supply the larger pin centre part.

2. Interesting on the power plug length .... I'll check the one I am using because have not had a problem with the plug clicking into place.

3. I'll update the document to reflect a larger hole diameter. I suspect if the drill wanders a touch when drilling a slightly larger hole maybe required to get the DIN plug to line up with the socket ..... mechanics always the tricky part.

4. I'll see if I can get some slightly longer clips designed for deeper plastic.

5. The current PCB V1.1 has slightly larger holes for the LED & motor breakout and the kit is supplied with five pin molex headers. So you solder in the headers and plug the motor directly into the PCB to test. Once tested you can cut the lead from the motor and use this lead + plug to wire up the LED's. See attached photo of the motor plugged in for test.

6. Yep mounting is down to personal preference - I bought some magnetic sticky plastic strip and fitted this to the mount and focuser case. The focuser controller just sticks to the side of the mount.

More feedback the better I say

Very pleased all is working well .... i'll get into looking at the issues ASAP !

Cheers & clear skies,

Dave

[wasyoungonce (Brendan)]

Hi Dave

Thanks for the feedback. re: your attached image......"them's the connectors I was looking for"! They are slightly lower than the std polarised SIL!

As usual Dave.....your always one or two steps ahead!

As for a flanged case....I was thinking it would easy to just use some sticky pad under the case and wrap zip ties around the OTA so they hold on to the flange lids..simple...well for me but of course this may not suit others.

Brendan

[dtrewren (Dave)]

Hi Brendan,

I was a bit upset about the headers on the first revision of the board. I had intended headers to be used in order to make build and test easier. Unfortunately, I let the PCB fabrication house choose the drill sizes based on the files I uploaded. They chose a drill size just a tiny bit too small to accept the square section header pins. I tried drilling out the holes but it recked the through hole plating and ended up looking a bit of a mess. So upshot was the first revision had to be wired but V1.1 can use the headers.

On holiday in Spain at the moment, really clear skies wish I had my Astro gear. However, after the girls have finished packing I only had room for my toothbrush and a pair of trunks

Clear skies,

Dave

[wasyoungonce (Brendan)]

Hi Dave

Installed PC driver 3.5 from your site, installed ok (it stated on the ASCOM install routine..."...install PC driver ver 3.5"), but when using your older client.exe I noticed my PC driver was identified as ver 3.4...yet I installed 3.5. I re-installed 3.5 again (twice) same issue.

See screen grab.

In properties tab it displays PC driver 3.4! yet I installed 3.5! I'm only using client for testing...sorry I didn't try focusmax. Edit: same in focusmax properties.

Brendan

[dtrewren (Dave)]

Hi Brendan,

That's a bit strange ....

I suspect it will be one of two things. File version control went crazy (very unlikely) or operator (me) went crazy and didn't update the version variable before compiling

Soon as I'm back from holiday in very sunny Spain I'll recompile and upload.

Sorry about that .....

Clear skies,

Dave

[dtrewren (Dave)]

Hi Brendan,

Back from holiday now so have had a look at the driver issue you reported. I have downloaded the latest driver and installed and can confirm it is V3.5 with the new client reverse checkbox.

I suspect I might know what your problem is. I think you may have a driver dependency situation when installing the new driver. This is 'usually' caused by having a client program active when installing the new driver. Because the client puts a dependency on the driver Windows cannot uninstall the old driver completely and leaves the .DLL in place. It's a safety feature but a PITA IMO.

- Close all client programs
- Uninstall the old V3.4 driver
- Check for the file 'ASCOM.SharpSky.Focuser.dll' in this directory
C:\Program Files\Common Files\ASCOM\Focuser
- If said file is present after uninstalling delete the .dll file

Install the new driver.

I can tell you have the V3.4 driver and not the V3.5 driver from your screen shot because it does not have the client reverse checkbox.

Hope that fixes the problem, please let me know.

You Aussies no what's good for sunburn - apart from playing in the sea with no sunblock on

Clear skies,

Dave

[wasyoungonce (Brendan)]

Thanks Dave.

I found an uninstaller for sharpsky 3.4 driver in the C:\Program Files\Common Files\ASCOM\Focuser\....

I just used this and now installed PC driver 3.5.....many thanks. I was looking for the dir to find the dll ...didn't find it ..until now.

The new ver 3.5 driver has a .dll in the same location no uninstaller.

Have much on my plate at the moment so many thanks for your help and patience.

As for sunburn....always keep your swimming trunks on....lesson No1, when at the beach! I found that the hard way once, when young .

[Astroman (Andrew Wall)]

I am thinking of getting this project instead of an accufocus, seems to offer a whole lot more for little more money. Have PMed David re: pricing to Australia

Sunburn, get some Aloe Vera Spray, works a charm on sunburns....

[dtrewren (Dave)]

Hi Brendan & Andrew et al,

You guys did make me chuckle even though my sun burn smarts a tad. I was actually snorkelling at the time - although complete with trunks, the thought of anything less makes me feel a little ..... ill. School boy error swimming about with back to the sun, tend to lose track of time and by the time I was out I was a little .... pink

The driver does generate an uninstall utility it should be in :
C:\Program Files\Common Files\ASCOM\Uninstall\Focuser\Sharp Sky

And is named imaginatively : unins000.exe

This is the .exe that Microsoft executes when you ask to uninstall the driver in the control panel.

Andrew I sent a private message (for some odd reason) I'm adding on an extra £5 for postage down under. It's about £3 in the UK and about £8 for Australia which I though was quite good as it gets there in about a week.

Clear skies,

Dave

[budman1961 (Andrew)]

Wow, what a fantastic project.....Do you ship to the USA, and how much is the kit in US dollars?

Andy

[dtrewren (Dave)]

Hi Andy,

Very pleased you like the design, thanks for the feedback!

Sure I can send to the USA, just a stones throw over the pond compared to the guys down under. I suspect postage will be about the same so the kit comes in at £73 or roughly $113. If you use PayPal you can simply set the currency you wish to pay in and the conversion is worked out for you...... such a great thing PayPal.

Send me a private message with your details and I can get a kit going transatlantic.

Cheers & clear skies,

Dave

____________________________

[dtrewren (Dave)]

Hello,

Just a little note :

Just to keep the thread clean and non commercial please direct any questions regarding kit supply or pricing via personal/private messaging. That way the thread stays purely technical

Cheers & clear skies,

Dave

[garymck (Gary)]

Hi,

just completed my Sharpsky focuser. All in all I would say that I spent about 4 hours putting it together. Everything worked first time apart from the manual control which I botched up with lousy soldering due to trying to solder a din plug (god I HATE din plugs) left handed as I have a broken right wrist. After replacing this plug which ended up looking like it had been attacked with a blow torch, it worked perfectly. If I can put it together then anyone can....best value astro purchase I've ever made. Dave also replied patiently to my pleading for help emails. Just have to get the motor to focuser connector bored to the right size for my focuser an I'm go.

cheers
Gary

[MrB (Simon)]

Originally Posted by garymck

(god I HATE din plugs) left handed as I have a broken right wrist.

Haha. Yes I hate them too.
I've been using a soldering iron since I was about 7, but I could not imagine soldering with my left hand! Nice work!

[dtrewren (Dave)]

Morning Gary et al,

Excellent news, very pleased you sorted out your manual focus control - was scratching my head trying to figure out what might me the problem

I'm the other way around ..... born a left hander, they tried to beat it out of me as a child but still one of the minority. Soldering with my right hand would be like soldering on the end of a ten foot pole.

With regard the DIN plugs. What I do is assemble the PCB first, then plug the DIN plugs into their respective sockets and then solder the wires on while they are plugged in. Having them plugged in provides a stable platform so you are not chasing them all over the bench. Also the socket & PCB acts as a heat sink so the plug body does not deform with the heat and obviously the socket holds all the pins in place. If you don't use too much heat the plug might even come out of the socket after soldering to

The suns out and I can see sky in the UK ...... miracle !

Clear skies,

Dave

[wasyoungonce (Brendan)]

Dave and I spoke about the DIN plugs, the consensus is that at least these have some protection from moisture. The Alternative is RJ type connectors which offer little moisture resistance.

I'm not a great fan of the DIN/MiniDIN but hey they work and surprisingly well in this case and lock in position fine. Down side is almost impossible to line up in the cold & dark. Daub a locator paint mark on the connector and housing to show the key-way.

Just wish the mini DIN body back shell were a little shorter, that would help.

[dtrewren (Dave)]

This is very true those DIN plugs can be a little fiddly in the dark while holding a large glass of red My controller is fixed to the mount and I leave the manual control permanently plugged in and then attached to the pier with a little square of Velcro.

I am not really doing any visual work, only photography and have the focus positions for various setups stored as pre-sets on my client. As a consequence don't really use the manual control very often. It is useful if the DSLR is on the scope and you want to get approximate focus using live view. Generally hit the focus pre-set and then nail focus with a mask. Then obviously forget the mask and have to do the first sub again

Clear skies,

Dave

[wasyoungonce (Brendan)]

I meant to say for those using ML stepper (re:Hurst) motors. When I 1st used the controller with this combo I got a lot of miss-stepping and motor buzz/chatter.

I had to set the "Period per step" (in ASCOM properties handling tab) from the std 35ms to around 60ms. Once done...all good.

Something to do with the way the Hurst is wound? This didn't happen with the cheaper ebay motor I tried.

Anyway just mentioning this so anyone else seeing this will know what to do.

[allan gould]

I've just started soldering David's controller and stepper motor system after receiving it mid week. I confess that my previous attempts at soldering were absolutely pathetic but I read the instructions and went through to the final steps. Amazingly i plugged it in and it worked perfectly first time without any drawbacks. Could not believe it, not because the kit was complicated but that I could do it with no previous soldering experience.
I was amazed at the versatility of the kit and how well it's been thought out.
My hats off to you David for such a brilliant kit, great web site and for making this available to the amateur community.