DIY Horizon to Horizon Polar Mount

[blademedia]

Brunel would be proud of you!

Will watch this for tips
Britain's Greatest Bridges - what time is it on TV? Episode 3 Series 1 cast list and preview.

 

[blademedia]

Back to work on this today. I need to get sprocket and chain before cut steel for pivot.


Went to shop to make enquiry and get prices. they needed to know how long motor takes to make full resolution for correct sprocket and chain. wanting roughly 6min end to end 180 degree (hope to see 60E 60+W with moving dish location.

Did test on rotation 37 seconds 1 resolution. go back tomorrow with information and hope they have stock,

Rough price for parts Sprocket £22.50 Taper lock £11.36 Chain £6.20 a ft. need just over 4ft. not bad was expecting pay more

 

[archive10]

Sprocket

All other things about your great project being equal - Isn't that just a beautiful word? Sprocket...
you can almost taste something between a sprout and a rocket...

 

[blademedia]

beautiful word? Sprocket

Sprocket picked up st1

I was limited to size of sprocket could use without having shaft machined down, (need to buy a lathe) now calculated time end to end is 4.30 same as the one I am coping. sure this will be ok

Also bought oilite bushes for pivot. parts £78 can do more work on this now

 

[blademedia]

Few more parts picked up. spending more time finding parts than working on this.

 

[blademedia]

Just had a hour and installed chain

 

[archive10]

Just had a hour and installed chain]

Very nice. Good progress!

Maybe it's just me not being mechanically inclined, but i got the impression that the chain wrapped around the sprocket in an omega-shape to ensure maximal grip for heavy load situations (wind etc)?

 

[blademedia]

Very nice. Good progress!

Maybe it's just me not being mechanically inclined, but i got the impression that the chain wrapped around the sprocket in an omega-shape to ensure maximal grip for heavy load situations (wind etc)?

Thanks st1, various ways it can be done, I don't see any issues doing it this way. it will have to strip teeth. the sprocket is made to take very high torque

 

[blademedia]

Thanks st1, various ways it can be done, I don't see any issues doing it this way. it will have to strip teeth. the sprocket is made to take very high torque

Having said this

but i got the impression that the chain wrapped around the sprocket in an omega-shape to ensure maximal grip for heavy load situations (wind etc)?

I think your right st1 this way would be better, for the sake of two extra sprockets and a 1ft of chain i will take this route, ive come this far shame to scrimp on a few extra parts, thanks for the suggestion

 

[Trust]

Having said this



I think your right st1 this way would be better, for the sake of two extra sprockets and a 1ft of chain i will take this route, ive come this far shame to scrimp on a few extra parts, thanks for the suggestion

That why I pointed to the 2 chain tension wheels in post #19
Never thought you gonna do it wthout them .

 

[blademedia]

Ive made a few mounts in the past but never a chain driven one, thought one sprocket would be ok, but after installing the chain only two teeth hit the chain,

Ok it would work and teeth are hard to strip, but its far better like st1 says, I am no expert and don't claim to be, its all a learning curve, this way is far better than my first intension,

Now I can see how it works its obvious this is the way to go, this part was hidden from my view, thanks again for the guidance

 

[blademedia]

Back on track, no bearing type in stock. will replace these at a later date

 

[Trust]

Did you check the outgoing shaft of the gearbox with the sprocket , at play ?
Because common gearboxes are made to operate most of the time in one direction and to avoid unnessasary friction , they have some play at new .

 

[archive10]

Ive made a few mounts in the past but never a chain driven one, thought one sprocket would be ok, but after installing the chain only two teeth hit the chain,

Ok it would work and teeth are hard to strip, but its far better like st1 says, I am no expert and don't claim to be, its all a learning curve, this way is far better than my first intension,

Now I can see how it works its obvious this is the way to go, this part was hidden from my view, thanks again for the guidance

No worries, only happy to be able to chip in on a project I would never be able to undertake myself!

 

[blademedia]

Oilite bushes in the chain ring part, pivot and gearbox holder to make up next

 

[blademedia]

Did you check the outgoing shaft of the gearbox with the sprocket , at play ?
Because common gearboxes are made to operate most of the time in one direction and to avoid unnessasary friction , they have some play at new .

No play in this one trust, no chance of moving anything on the output shaft its solid

 

[blademedia]

Oilite bushes in the chain ring part

Wasn't happy with my drilling /measuring, was just over 1mm out, so welded holes back up and re drilled, its perfect now weld nut to thread to make long bolt, nylon locking nut on bottom

 

[RimaNTSS]

its perfect now

Nothing and nobody is perfect, even you @blademedia , just kidding. Looking forward to further progress in your interesting project.

 

[blademedia]

Nothing and nobody is perfect, even you @blademedia , just kidding. Looking forward to further progress in your interesting project.

This is true , another possible issue that I am aware of the vertical parts should have been made from 50mm, ive taken a gamble that I wont be able to see the arc before it hits the vertical,

If I can see further I will V it out to allow more travel, rest is plane sailing now all the hard parts finished

 

[blademedia]

Plates for pivot cut and drilled just need welding in place