Making a TekkyDave AAF2

[Stub Mandrel]

Phew, I've just got Sharpcap on my desktop thinking it's talking to an AAF2.

My Arduino Nano hasn't got any hardware attached, but that seems to be a minor issue...

What I've found really disturbing is that the Arduino IDE happily announces errors when trying to program the Nano but gives no indication of success, no progress bar (after compilation), no messages, nothing! Completely unlike using the AVR development tools and programmers...

Now I've discovered it's for monopolar steppers ... well I have loads of monopolar steppers of all sizes, including the tiny geared ones (hooray!)

But it could take months to track down the little driver boards... (BOO!!!)

I may even find a bluetooth serial adaptor while I'm searching (hooray!)

Thanks to @tekkydave for all the effort put into this and particularly the meaningful comments!

See:

 

[Stub Mandrel]

Wow! This is so cool. I found the stepper drivers - attached to the correct geared steppers!

I wired up except I reversed the connection order to allow a compact configuration (I figured this might reverse stepper rotation at worst):

Connected it all, and lo and behold it works!

I love the rippling LEDs, but might cause upset on a dark site, so I'll put it inside a white PLA case to mute the effect.

 

All so easy to do that the only challenging bit is just making a case (and adding a switch)!

Edited June 1, 2020 by Stub Mandrel

[fozzybear]

2 hours ago, Stub Mandrel said:

Wow! This is so cool. I found the stepper drivers - attached to the correct geared steppers!

I wired up except I reversed the connection order to allow a compact configuration (I figured this might reverse stepper rotation at worst):

Connected it all, and lo and behold it works!

I love the rippling LEDs, but might cause upset on a dark site, so I'll put it inside a white PLA case to mute the effect.

 

All so easy to do that the only challenging bit is just making a case (and adding a switch)!

it's alive great job

[fozzybear]

Neil,

how's the project coming along and what scope are you planning on using it on?

Andy

[Stub Mandrel]

20 hours ago, fozzybear said:

Neil,

how's the project coming along and what scope are you planning on using it on?

Andy

Hi,

The electronic bit Just Works (TM)! Fire up Sharpcap and it does everything you expect, even moving rapidly then slowing down at the end of a long move. Only thing is it was a tad slower to respond than my ZWO EAF, presumably because it uses a smaller stepper with a bigger gear ratio. I changed the stepper speed settings in line with Dave's suggestions to tune it up to be a bit faster.

One thing that's interesting is it happily runs off the 5v USB supply with no 9V battery fitted. It will only draw about 145mA even when two coils are energised, so this should be fine - there's plenty of torque.

I need to make a fixing bracket and adaptor, to be honest the only thing holding em back is it's the ED 66 scope I made myself and I'm reluctant to remove my lovely home-made knob!

[fozzybear]

Neil,

This has me thinking for my SW 72ED and find a bracket to fit the motor to or find one on thingiverse. I've got Nano's and some of those 5v motors with boards somewhere (stolen from my son) 🙊 he won't miss them. now to look at @tekkydave Arduino code

would you use a direct coupling or belt drive?

Cheers

Andy

[Stub Mandrel]

On 13/06/2020 at 22:55, fozzybear said:

Neil,

This has me thinking for my SW 72ED and find a bracket to fit the motor to or find one on thingiverse. I've got Nano's and some of those 5v motors with boards somewhere (stolen from my son) 🙊 he won't miss them. now to look at @tekkydave Arduino code

would you use a direct coupling or belt drive?

Cheers

Andy

I'm going to use direct coupling like the ZWO units.

Yes I might end up with a 3D printed bracket, rather than mill away 95% of a lump of alloy!

[fozzybear]

just found one of Roberts 3d printed brackets for a Crayford focuser  and the above motors

https://www.thingiverse.com/thing:3731843

[Stub Mandrel]

I'll need to do my own design, because it's a self-made focuser.

[fozzybear]

14 minutes ago, Stub Mandrel said:

I'll need to do my own design, because it's a self-made focuser.

I forgot you made your own

[Stub Mandrel]

I might make another one, for my 150PL, if I do that will need some sort of belt drive because it's the focuser you can't the the knobs off.

It looks like if you take the rubber grip off the knobs, they are like a big pulley.

[Dr_Ju_ju]

Instead of milling away an ally block, just get some 50x150 3mm ally angle & drill holes accordingly, or print one using one of the designs on Thingiverse\Tinkercad etc. or even knock one up in OpenScad, it took me all of 30 mins in OpenScad, and I can easily mod the design for other ota's .... 

[Stub Mandrel]

For the amount I need, it would be cheaper to use an existing offcut, or I can copy ZWO and just screw two bits together.

But I'll probably 3D print it for now and make a pretty one when my anodising is set up again.

 

[JamesF]

Other than sorting out life under our new viral master, making up the bracket has probably been the major reason for the pause in constructing my Robert Brown auto focuser.  I need to make up a bracket to fit a Steeltrak.  I really must get on with it.  How much cost/harassment is it to set up a small anodising rig, Neil?

James

[Gina]

I have a thread on it somewhere but haven't done any anodising for years.

[stash_old]

All this 3d printing mumbo jumbo - zinc fence panel bracket + 7lb hammer+anvil -cold form shape - drill - all done 20mins LOL and doesn't destroy the planet using all that electricity/plastic/nylon etc 🙂

[Dr_Ju_ju]

and how did the zinc fence panel, hammer & anvil actually get made...  Oh by destroying\burning\polluting the environment.... 

[stash_old]

2 hours ago, Dr_Ju_ju said:

and how did the zinc fence panel, hammer & anvil actually get made...  Oh by destroying\burning\polluting the environment.... 

Originally but it was recycled by me 🙂 and the hammer/anvil is over 45yrs old.  🙂 

[Dr_Ju_ju]

And I use a 200+ year old bake stone, but that still doesn't mitigate the fact that it and their production entailed the destruction\burning\polluting the environment....

And I'll quite happily admit, that 3D printing can also be as bad for the environment, and can be argued that it is more wasteful and even heavily toxic....  

 

[stash_old]

11 hours ago, Dr_Ju_ju said:

And I use a 200+ year old bake stone, but that still doesn't mitigate the fact that it and their production entailed the destruction\burning\polluting the environment....

And I'll quite happily admit, that 3D printing can also be as bad for the environment, and can be argued that it is more wasteful and even heavily toxic....  

 

No matter what - the same applies to all the kit you/we use in Astro world. 

Sorry Stub Mandrel about high jacking the thread. 

I will not  post anymore on this thread about environment but if Julian wants to start up a new thread on the whole subject fine.

[Dr_Ju_ju]

Absolutely, but no more 🙇‍♂️ .... sorry Stub

[Stub Mandrel]

22 hours ago, JamesF said:

Other than sorting out life under our new viral master, making up the bracket has probably been the major reason for the pause in constructing my Robert Brown auto focuser.  I need to make up a bracket to fit a Steeltrak.  I really must get on with it.  How much cost/harassment is it to set up a small anodising rig, Neil?

James

More harrassment than cost, you need to safely access and store sulphuric acid luckily a dilution just below the level where you need a licence for it is ideal (about 12%). Also sodium hydroxide, for stripping and degreasing. So a sealable plastic box as a tank for the acid, that lives in a bowl with washing soda in it  to neutralise any drips. Lots of PPE - goggles, gloves, plus croc clips, wires...

I bought proper dies (which will last a long time before being exhausted) and sealer, as these make the colours more consistent.

I made a cathode by melting down lead pipe and pouring it into  a (very dry) wooden mould.

I have a long titanium rod for mounting workpeices, it needs to be polished to a clean finish with wet and dry to ensure good electrical contact.

Other equipment is a 4A transformer from an old battery charger and an old style moving iron 5A meter. The meter swings full scale then rapidly drops, rather than set the current I keep going until it starts to drop.

[Stub Mandrel]

2 hours ago, stash_old said:

No matter what - the same applies to all the kit you/we use in Astro world. 

Sorry Stub Mandrel about high jacking the thread. 

I will not  post anymore on this thread about environment but if Julian wants to start up a new thread on the whole subject fine.

 

2 hours ago, Dr_Ju_ju said:

Absolutely, but no more 🙇‍♂️ .... sorry Stub

LOL!

I'm a chartered environmentalist.

My main guilt is the large amount of failed 3D print prototypes I have building up; quite keen to look at a way of turning them back into filament.

But... the environmental cost of a kg of PLA every month and the relatively modest amount of power used by the printer? Compare to any hobby or pastime that requires you to drive.

As for my hobbies in general they don't involve large amounts of material and put me in good position to keep, repurpose, repair, reuse, recycle...

[Gina]

I looked into a "RecycleBot" some time ago and found that the cost in power needed exceeded the cost of new filament!!  Also, you can only recycle once as the filament quality is reduced.  So I am left with a number of dustbin bags full of failed and experimental prints.  I have improved my environmental overhead though by pretty much sticking to PLA which is plant based rather than oil based and will "return to earth".

[Dr_Ju_ju]

I always ensure all failed prints \ off-cuts \ whisps etc. are all bagged in a paper bag & put into our (Runnymede) recycling bins, which are collected every other week.

If I was living in Rhondda, Cynon, Taff (Birth Home), they are even more strict, and would fine you, if you put anything that could be recycled into the wrong receptacle.....