Good stuff

[Ags]

I recently acquired an RC6, HEM15, ASIAIR and guide camera. I just want to say it is a pleasure everything works together so flawlessly! I love the smooth hum of the mount as it zips about. Plate solving is so cool I'm not bothered by the occasional failures. The Air makes guiding and capturing hassle free. The RC6 is superb and collimation was not as hard as I feared!

[vlaiv]

Happy to hear that all is working fine together!

Btw, is this thread where we share good stuff (don't want to hijack the thread ...)? I have several things I'm happy about as well ...

[Ags]

Share away - more good stuff is good!

[vlaiv]

Well ...

I'm just finishing my design for 3d printed "class 5" mount:

And it's been printed as we speak ... (some parts at least) - here is "creative mess" on my desk:

(sorry about poor focus)

... meanwhile, my obsy is also being finished as we speak or rather type (well, not so much finished as being worked on - I still have a lot to do to finish it after construction is done):

 

[Ags]

What a view!

[vlaiv]

6 minutes ago, Ags said:

What a view!

Not sure if you are referring to the mount or the countryside

Just in case you are referring to the countryside and view from my terrace - here are few better pictures. I've been very lucky to be able to get such view - my astronomy interest contributed somewhat to that as well, as I chose my property based on location and access to clear skies.

Above is the view towards the south. On a good day, I can see mountain peaks that are 70+ km away, and power plants (man made structures) that are 50-55 km away

This one is view due North. I'm basically at the edge of National park, maybe few hundred meters away - there are like 2-3 rows of lots between us and national park (you can actually see game keeper tower in the image.

Both images were taken from the terrace on the upper floor.

Obsy has 360 degree sky access from maybe 15 or so degrees upwards (depending on where you are facing - south horizon completely open).

 

[Vulisha]

Quick question,  what would be "class 5"? You mean eq5, cg5? 

 

Also what performance do you expect of it? I am looking forward to more detailed post!

[Elp]

48 minutes ago, vlaiv said:

Obsy has 360 degree sky access from maybe 15 or so degrees upwards (depending on where you are facing - south horizon completely open).

Very fortunate to live in such an area for astro. Good stuff.

[vlaiv]

1 minute ago, Vulisha said:

Quick question,  what would be "class 5"? You mean eq5, cg5? 

 

Also what performance do you expect of it? I am looking forward to more detailed post!

Yes, that is the sort of thing I had in mind - both carrying capacity and general performance of something like EQ5/HEQ5

Aim is to make (mostly) 3d printable mount that will outperform available offerings in this class for the fraction of the cost. I'm most likely to release it as open source so that anyone can build one or enhance it / design accessories or adapters or whatever, and I'll even possibly offer kits at some point as small business kind of thing. I don't think I have the capacity to go full product with support kind of thing at target price point, so I'm thinking more along the lines of approach found with 3d printers - there are open source builds where you can source parts your self - or purchase kits that are partially or fully ready to be assembled (depending on whether you want to 3d print some parts yourself or not).

I also have two additional ideas for this mount - one is being tested at the moment (but I'm not really convinced it will be good solution). I've developed novel reduction that is fully friction free. It uses magnetic fields to transfer motion and perform mechanical reduction. I've already built 3 prototypes, third one is ready for testing to see how it will actually perform when attached to stepper motor (let's call that stage one testing) - uniformity of motion, any level of backlash or elasticity in the system and so on ...

Second idea is much simpler - but it needs professional tools and skills to be produced. It is high reduction ratio friction gearing in very small package. I can't find anyone that will make me couple prototype samples at reasonable cost. Offers that I received for making those parts (few iterations - not sure how many prototypes I'll need until I'm satisfied with performance) - are high enough that it's more cost effective just to invest in tools and make those myself (and that is the plan now - get tools at some point - if this mount turns out to be a usable thing).

 

[Floater]

1 hour ago, vlaiv said:

I also have two additional ideas for this mount - one is being tested at the moment (but I'm not really convinced it will be good solution). I've developed novel reduction that is fully friction free. It uses magnetic fields to transfer motion and perform mechanical reduction. I've already built 3 prototypes, third one is ready for testing to see how it will actually perform when attached

Wow! 

[maw lod qan]

Seeing something 3d printed like that always amazes me!

And the view is beautiful!

[vlaiv]

4 minutes ago, Floater said:

Wow! 

I know it sounds super fancy - but it's actually quite a simple idea. It borrows from already known mechanical principles ...

Look up cycloidal reducer online and here is a "teaser" video of first prototype / proof of concept in action:

 

That is just a proof of concept. Inner black disk is just held in place by a single bearing. It has no other physical contact with the rest of system. Similarly input shaft is only attached to "housing" / cage via two bearings.

Later prototypes are actually two stage models that have reductions in range of few hundred to one.

This was second one - but it did not work because too tight tolerances. Magnets just kept dislodging themselves and sticking to other magnets:

[Vulisha]

This is soooo stunning!

Regarding magnet drive I had an idea like that as well but I thought natural magnets would be too weak, and doing electromagnets would be just too much.

 

I also dabbled in my own mount design, tried to do 3dprinted harmonic drive for nema 17, but that ended not being so precise in the end, so I put it all on hold 

[vlaiv]

2 minutes ago, Vulisha said:

Regarding magnet drive I had an idea like that as well but I thought natural magnets would be too weak, and doing electromagnets would be just too much.

Neodymium magnets are very very strong.

However, I think there are two major issues with above approach with magnets:

1. Ideal configuration for above type of reduction is some sort of uniform rolling motion - imagine two circles - one large and one just a bit smaller. You can roll smaller circle on inside of larger one just by applying ex-center wobble type of motion on input shaft (think hula hoop), but in order to do that smoothly you really need certain profiles. Cycloid, involute or regular smooth (friction drive) profiles all provide nice uniform motion.

Magnets on the other hand don't have this smoothness. They have variation in their strength, variation in assembly position and magnetic fields don't provide smoothness in changing configuration (drop off with square of distance for example). This will mean that reduction box will have very distinct periodic error.

I'm hoping that it will be easy enough to capture this error and program it into controller in form of periodic error correction. That is one of things I'll be testing with this prototype in upcoming tests (need to first help a friend with Heq5 belt conversion - then we will have time for testing).

2. Magnets are not stiff enough, so I'm worried about elasticity of the mount assembly in the wind - or in general like when accelerating / decelerating during guide cycles.

12 minutes ago, Vulisha said:

I also dabbled in my own mount design, tried to do 3dprinted harmonic drive for nema 17, but that ended not being so precise in the end, so I put it all on hold 

Here are two ideas:

- lookup split ring compound planetary gear reduction. This is "basic" form of gearbox that I plan to implement on above mount.

- have a look at this:

https://www.aliexpress.com/item/1005005537731414.html

(which is now unfortunately out of stock).

Such reduction box can be paired with two Gt2 belts to get very decent reduction  4:1 x 30:1 x 4:1 = 480:1

[Vulisha]

This is actually super cool idea and never heard about this gear, and gave me another idea, planetary+strainwave drive. Bottom drive planetary x3, and top drive harmonic x30, 90 reduction from single drive, and on top drive you have benefits of harmonic drive(smaller tooth more contact, less chance of slipping)

[pipnina]

On 26/05/2024 at 12:10, vlaiv said:

Well ...

I'm just finishing my design for 3d printed "class 5" mount:

 

And it's been printed as we speak ... (some parts at least) - here is "creative mess" on my desk:

 

(sorry about poor focus)

... meanwhile, my obsy is also being finished as we speak or rather type (well, not so much finished as being worked on - I still have a lot to do to finish it after construction is done):

 

 

I'm wondering if you have a progress thread for your mount endeavors, Vlaiv?

I know you have looked at many systems but having just come across this video, I wonder how you would see it as a mount power system?

 

[vlaiv]

5 minutes ago, pipnina said:

I'm wondering if you have a progress thread for your mount endeavors, Vlaiv?

I'm not sure.

I'm quite certain I started a few threads on similar topic when I was contemplating the idea, but I don't think I have actual progress thread.

Here is sneak peek thingy:

That is wedge alt rocker / mount adapter thing. It's massive - I might have gone overboard with dimensions, but I'm going to see it thru before I decide on perhaps another approach.

I did think of CEM idea for a while now - I think it lends itself better in couple of ways to DIY mount - reducers can be mounted inline but still away from the axis. Altitude control can be implemented better. My current design allows for only about 15 degrees of adjustment, maybe 20 total (+/- 10). It's been designed for 45 latitude (that is almost exactly latitude I'm at) - but can be changed.

Then there is this thing:

Which is just brilliant idea to cheaply / off the shelf constrain mount altitude rocker in CEM design:

12 minutes ago, pipnina said:

I know you have looked at many systems but having just come across this video, I wonder how you would see it as a mount power system?

Yep, seen that one recently as well - but unfortunately, it can't be used with mounts. It is constraint to semi circle - or rather segment of a circle. It can't provide continuous motion.

Ra does not need to track the full circle, but DEC actually needs to be able to do so (and regularly does so when imaging near meridian) from + to - 180 degrees. It is also limited to single stage (because in dual or multiple stages we again run into segment of a circle constraint).

I think that I'll make one design with multiple belt stages, so it will very similar to Avalon Linear in that regard.

Btw, here is similar and also cool design that works on the same principle as that with rope (only using timing belts):