Vroobel

Hi. I still struggle with some parking issue: sometimes the mount stops much earlier than it suppose to do. But instead of wasting the time and looking for a solution, I improve the mount. I move step by step towards the maximal ease of assembly outside. Recently i worked on a way of arranging the electronic stuff and cables. Finally I figured out how to avoid tangling and hooking on obstacles like leveling knobs. The electronics found home inside one side of the road he fork. Its temporarily fastened on an MDF board, but I think that is a good place to it. I try to finish building this modular setup before clear nights begin.

Hi. Around one month ago I downloaded and installed the Astroberry on my new RPi4. I like the idea of everything in one place. But as my mount isn't entirely ready I decided to use temporarily the APT application, especially that more people use the Windows and ASCOM compatible software. I should take it into account when I need a support if any problem appears. And indeed, some problems appeared. Just for reminding, I use OnStep @ MKS Gen-L v2.1. One is about parking in wrong position. But at this stage it's acceptable. Second problem is more annoying, because every Park or Unpark command finishes with a crash of the Ekos-KStars. After several days of looking whether it's caused by the OnStep firmware or the MKS hardware I finally found a solution: the Ekos at 3.4.3 version had a conflict with the INDI driver for the OnStep. After updating and full-upgrading the Astroberry the problem of crashes disappeared at all. https://onstep.groups.io/g/main/topic/75830899?p=,,,20,0,0,0::,,,0,0,0,75830899

Hi, I have pleasure to present a first GoTo test: Polaris -> Deneb -> Polaris, performed at home because of rain. 😒 It's made with some stress included. I invested lot of money in fantastic high performance TMC5160 drivers, they are so nice, silent, but not working... After several seconds of work, in random moment they move into disabled mode, steppers stop while an application (the APT) still works. This is very confusing and generates big mess. I tried to find solution looking at forums, but people don't know why it happen, even if it's known problem. I still have some other drivers: A4988, DRV8825 and LV8729. The A4988 offers 16 micro steps while I need at least 64. It's current is not big enough as well. The DRV8825 offers 32 micro steps and also low current. There is big friction in the axes, the Ra needs 3A in GoTo mode, the Dec one needs around 2.5A. The LV8729 is quite good, it offers 128 micro steps, while the 2A of current cause that I can boil eggs... But it works fine for a while. And the poor TMC5160 ones... I told sorry to my DM556 industrial drivers which I bought several months ago. They offer 128 micro steps and 5.6A current! 😳. I set the LV8729 mode and connected everything with wires. It looks odd, I know, but it works perfectly. At home...

Yes, it is! 😁 This kind of harmonic drives work in a joint of industrial robot arms without a counterbalance. The arms are very heavy itself, while they are much more efficient than my mount. 😊 I see, that the fork is OK, when OTA is aimed somehow forwards or backwards, but I expect some bents, when the fork will rotate more left or right. That's why I have to consider welding, even if the profile and bolts are strong, they aren't strong enough to hold themselves and the fully equipped OTA. I'll check it as soon as the electronic stuff is ready and the weather allows.

Yes, that's strange. My one is simple. 😁

Hi, This is a fork mount based on a heavy 101:1 harmonic gear. It's designed for a 10" Bresser Messier Newtonian telescope, but will be able to drive any smaller OTA with standardised mounting. It's not in action yet, just finished enough to test it, but unfortunately there is cloudy sky, like usually when you want to test a new stuff... Here is link to a live story of my fork mount: I hope to show it in action very soon. 😊

Ok, so last several days I was very busy and productive. I designed and printed many knobs for different bolts and nuts and also adapter for 1.25" ASI 120MM mini camera which will work with SW 8x50 finderscope as cheap guider. I finished slides to be able to move the wedge in the Az axis with minimal friction, so the base is ready in general. Thanks to advice another friend from the Polish forum I also replaced most of M6 threaded rods with short stainless steel bolts, spring washers and nuts. The fork is much stronger now. And finally I finished all the mount enough to test it in action. Now all the setup is at home as I have to prepare some box for electronic stuff. There is still lot of work to do, but the most important work is done. I had a plan to build a mount able to hold 30+ kg equipment. Accidentally I made a 70+ kg one... 😳 I confirmed it hanging myself on the tops of the fork - the mount didn't move at all. I am very tired, but happy! 😁

Hi Craig, Thanks for your advice. I am ready to lock it in both Az and Alt axes. The Az is physically done while the Alt is partly performed. I'll finish the Alt one later or immediately if needed. I considered it rather against wobbling, but 4 hinges and the top plate supported on sides should make it solid. The car jack can lift and hold at least a half of the 1 ton car, so I think the 80kg shouldn't be a problem. I'll consider the Teflon instead of brass or bronze. As long as the weather is not good enough for test I have to focus on something else.

Nearly done. Three days of drilling, welding, grinding, I'm really tired. The 36.5kg of the wedge can be easily moved in the Az axis using one finger on the knob. But the wedge + harmonic drive and stepper motor + fork + OTA and its accessories will weigh around 80kg together, so I expect some slight resistance. I'll check it very soon.

😁 Thanks, it's nice, but I am only a DIY enthusiast who has a goal and simply has an idea how to reach it. 😊

Today I made two parts of the base responsible for an Az adjustment. Its precision is around 6.25' movement of the wedge in Az axis for every single revolution of the knob.

It's very close to finish. I mean the stage, when I can test it in action. There is still lot of work: grinding and painting. I have also to find a home for its electronic stuff.

Ah, OK. I had this as plan on the beginning, but my (to be honest - not my) solution is better. In Liverpool latitude is over 53*, so I have lot of space under the top surface of the wedge for its jack and stepper motor. In your solution I would have only 37 degrees. Moreover, in present position the heavy harmonic drive, motor, fork and finally the OTA push the wedge down, which is natural situation for the car jack. In opposite position the jack should be pulled up, while I'm not sure if it's OK for it. To prevent it the wedge should be very heavy, much more than the present 36kg.

Up side down? It will still be wedge, but not equatorial and without possibility to fasten to the base. Is it what you mean?

Hi. I changed mind: I made the longest elements of the base 90cm long, the narrow side of the trapeze is 35 while the widest one is 80cm. It's long enough. The wedge weights 36.1kg, the base - 18.6, that means nearly 55kg together. Now I have to ask professional for welding.

Hi. 3rd day in row: determining a centre of the mass. It's necessary for determining a size of the base platform. Finally I was able to hang my OTA without stress, but there was still needed some significant load to let it fall over. It should be really big guider with accessories. Now I know that I have to build a kind of trapeze-shape base platform around 80cm x 40cm, 110cm long.

I finally made the wedge. It's not finished yet, but it's enough to begin working on it's base. I have to calculate a size of the base. Unfortunately it became very heavy. I knew it, the wedge and the base must be heavy, but I didn't predict that it is difficult to lift it and move. I hope Its stability will be the best award for the effort.

Hi, This time something not so effective, but it took me two days to perform. The wedge, even if heavy (around 40kg), after aiming on a polar with side bolts (soon) may move with any touch. After my friend, who shared the idea of the wedge with me, I'm gonna use vertical bolts and nuts with knobs for a better stability. The front arched holes are for this purpose. 12 degrees of the adjustment range should be enough. As the wedge is made using 6mm steel plate, when I hang the harmonic gear on it, and then the fork, OTA and accessories (around 50kg!) they will try to lift a rear side of the wedge. So the rear arched holes are there for preventing of that. There is a 16mm hole between the rear arched holes - it is for an Az axis. The 16mm treaded rod supported with two bearings under and over the plate will be there for the polar aiming purpose, but it will also partly hold the wedge on a base.

Hi, Next step is done: a main construction of the equatorial wedge. It's heavy, while isn't finished yet. Its weight will be nearly 40kg when finished. Some additional steel part will be welded and some ideas towards higher stability will be deployed. Soon.

😊 Thanks! I don't know what to say... Maybe, when finished, my mount may go on a date with your OTA? 😁 To be honest, I had not too many other real ideas how to build aluminium fork based on the flat harmonic gear. It must be strong and relatively easy to build at home.

Hi, After some attempts with the Arduino Mega 2560 and AstroEQ firmware I had to leave it. I asked its author for access to higher number of micro steps, but they didn't response. 32 micro steps mode gives me 2 arcsec accuracy in Ra axis and 2.5 in Dec one. It's not acceptable for me. I focused then on the OnStep @ MKS Gen-L v2.1. As I use Nema 23 stepper motors, I chose the Trinamic TMC5160 drivers, because they have external MOSFETs onboard and can give really high current with small amount of heat. As an author of the OnStep firmware warned, I had to cut a CLK pin. I am possibly a second person who had to solder it to GND (in GoTo slew randomly Ra or Dec didn't work, now is OK)... It doesn't work with the EQMOD, because it's compatible with Meade standard. Instead of that I used the APT app and of course the ASCOM Platform. I am amazed... 😳 It's so silent! I recorded a Sirius-Polaris-Sirius slew as sample, just to share it on the YouTube. You can hear the mouse click louder than the stepper motors. Special thanks for my friend Sebastian from our Polish astro forum. He shared his knowledge and experience with me and patiently answers all my questions.

Hi, I have to rest a bit from the manufacturing, so it's good time to think about hardware and software. In the beginning I had a plan to rebuild my own software written for my previous mount, motorised Dobsonian one. But my friend, another astronomer amateur and DIY enthusiast encouraged me to look at the AstroEQ or the OnStep software which together with the EQMOD or EKOS can work perfectly in my setup. Thus lest start with the Arduino Mega 2560 with the AstroEQ. I'll try to work on the EQMOD on Windows 7 laptop (I have spare one) - just to be familiar with that. I know that the Arduino Mega is the worst solution as it is not accurate, so I ordered the MKS Gen-L v2.1 which will work with the OnStep. It's the best mobo for the mount and works wireless. Finally I'm gonna install the Astroberry and EKOS on my Raspberry Pi 4 8GB.

It's very impressive! Today we have laptops, Raspberry PIs, Arduino, but I see you had to make your own controller. The construction must be very accurate. Are you still using it? Amazing job!

😁 As I wrote earlier, the jack is not my idea. If it can hold a weight of a half average car lifted, why not to use it for around 40kg load? The item in pics is a chamfer tool for any round rod, including threaded ones. I have made 48 x M6 rods that means 96 round edges to chamfer. This tool does it quickly and smoothly.