Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

23.5" f/3.6 Dob

  • Please log in to reply
424 replies to this topic

#26 grzesznypl

grzesznypl

    Viking 1

  • *****
  • Posts: 519
  • Joined: 07 Apr 2019
  • Loc: Jackson Heights, NY ... for now

Posted 07 June 2020 - 10:27 AM

It will be quite an adjustment from building and usage of your 0.8"/15" mirror. 6 point cell and silicon may not due grin.gif 

But seriously, hope to see you building nice world class cell, 18 or maybe even 27 pointer. I would choose later one for mirror of that size but its just me. 


  • Augustus likes this

#27 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 07 June 2020 - 10:55 AM

It will be quite an adjustment from building and usage of your 0.8"/15" mirror. 6 point cell and silicon may not due grin.gif
But seriously, hope to see you building nice world class cell, 18 or maybe even 27 pointer. I would choose later one for mirror of that size but its just me.


It is going to be 18 points most likely but I’m considering 27. Got gifted a stick welder a while ago so I just need to cut/drill the steel and make the triangles
  • hamishbarker and grzesznypl like this

#28 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 24,885
  • Joined: 22 Feb 2010

Posted 07 June 2020 - 11:21 AM

can you even lift a 120lbs easily, Augie? lol.gif


  • grzesznypl likes this

#29 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 07 June 2020 - 11:26 AM

can you even lift a 120lbs easily, Augie? lol.gif

Yes.



#30 Pinbout

Pinbout

    ISS

  • *****
  • Posts: 24,885
  • Joined: 22 Feb 2010

Posted 07 June 2020 - 11:54 AM

Yes.

"easily"... don't drop it. tongue2.gif

 

if you build the scope with motorized wheels, all you'd have to do use wifi your switch to the motors and drive it out of the garage.


Edited by Pinbout, 07 June 2020 - 11:55 AM.

  • Augustus likes this

#31 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 07 June 2020 - 12:01 PM

"easily"... don't drop it. tongue2.gif

 

if you build the scope with motorized wheels, all you'd have to do use wifi your switch to the motors and drive it out of the garage.

Idea is to have the whole thing on wheelbarrow handles and load it up on a ramp into the car. Mirror cell will be like a trapdoor or one of Dobson's mirror cells so I don't have to lower the primary in vertically.



#32 grzesznypl

grzesznypl

    Viking 1

  • *****
  • Posts: 519
  • Joined: 07 Apr 2019
  • Loc: Jackson Heights, NY ... for now

Posted 07 June 2020 - 12:01 PM

In my best days around 10 or so years ago I could deadlift almost 400lb now maybe 320lb on the best day. But there is huge difference lifting heavy bar few inches away from your body and crated 120lb mirror, 20" away from you CoG. I am certain there is no man on this forum that can do it himself. 


  • Augustus likes this

#33 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 07 June 2020 - 12:11 PM

In my best days around 10 or so years ago I could deadlift almost 400lb now maybe 320lb on the best day. But there is huge difference lifting heavy bar few inches away from your body and crated 120lb mirror, 20" away from you CoG. I am certain there is no man on this forum that can do it himself. 

The crate only has to make it twenty feet from my porch to the back of the garage, then it's just the 67-pound mirror to wrestle with (and I should only need to install that in the telescope once) so I'm not too concerned.


  • grzesznypl likes this

#34 grzesznypl

grzesznypl

    Viking 1

  • *****
  • Posts: 519
  • Joined: 07 Apr 2019
  • Loc: Jackson Heights, NY ... for now

Posted 07 June 2020 - 12:51 PM

Here is an idea for you 

Meticulously document your building progress, divide it into episodes and upload them into youtube channel. 


  • Augustus and hamishbarker like this

#35 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 07 June 2020 - 01:05 PM

Here is an idea for you 

Meticulously document your building progress, divide it into episodes and upload them into youtube channel. 

That is the plan.


  • Lukes1040 and grzesznypl like this

#36 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 15 June 2020 - 01:06 PM

The mirror has begun its journey and should arrive while I'm at Cherry Springs. 


  • coinboy1 and jtsenghas like this

#37 stargazer193857

stargazer193857

    Cosmos

  • *****
  • Posts: 9,925
  • Joined: 01 Dec 2013
  • Loc: Southern Idaho

Posted 15 June 2020 - 06:08 PM

That's a big mirror.
Don't let it lay flat on a hard floor, unless you have a plan for how to get your fingers under it.
  • Augustus likes this

#38 jtsenghas

jtsenghas

    Fly Me to the Moon

  • *****
  • Posts: 5,234
  • Joined: 14 Sep 2014
  • Loc: The flatlands of Northwest Ohio 41.11N --Bloomdale

Posted 15 June 2020 - 06:57 PM

That's a big mirror.
Don't let it lay flat on a hard floor, unless you have a plan for how to get your fingers under it.

Don't worry, UPS provided a wide handhold under one edge! (Right?)


  • coinboy1, Augustus, hamishbarker and 1 other like this

#39 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 15 June 2020 - 07:32 PM

Currently wondering where the heck I'm supposed to get thin and wide enough aluminum for my cell triangles. If anyone has suggestions for a source that'd be great.

 

That's a big mirror.
Don't let it lay flat on a hard floor, unless you have a plan for how to get your fingers under it.

Don't worry, UPS provided a wide handhold under one edge! (Right?)

After initial inspection it's probably going to sit on its side in the crate until the scope is almost ready.


  • Bob4BVM likes this

#40 Steve Dodds

Steve Dodds

    Owner - Nova Optical

  • *****
  • Vendors
  • Posts: 607
  • Joined: 02 Apr 2007
  • Loc: Utah

Posted 15 June 2020 - 07:43 PM

The mirror is sitting on cardboard and the back has a good bevel and the box is 6" oversize, it's pretty easy to get your fingers under it.


  • Augustus likes this

#41 Steve Dodds

Steve Dodds

    Owner - Nova Optical

  • *****
  • Vendors
  • Posts: 607
  • Joined: 02 Apr 2007
  • Loc: Utah

Posted 15 June 2020 - 07:49 PM

Currently wondering where the heck I'm supposed to get thin and wide enough aluminum for my cell triangles. If anyone has suggestions for a source that'd be great.

 

After initial inspection it's probably going to sit on its side in the crate until the scope is almost ready.

I would try Mcmaster-carr they have all sizes in many thickness


  • Augustus likes this

#42 Bob4BVM

Bob4BVM

    Vanguard

  • *****
  • Posts: 2,437
  • Joined: 23 Mar 2015
  • Loc: W. Oregon

Posted 15 June 2020 - 08:44 PM

Currently wondering where the heck I'm supposed to get thin and wide enough aluminum for my cell triangles. If anyone has suggestions for a source that'd be great.

 

After initial inspection it's probably going to sit on its side in the crate until the scope is almost ready.

Zane-

I mentioned this before but not sure if you ever looked up scrapyards ( metal recyclers) in your area. Any sizeable town will have one.  Saves you 70-90% over new Al stock, if that matters.

I buy most of my aluminum from our local one, they have everything from 1/16" thick to 2" thick in various shapes & sizes, certainly no problem finding the 3/16 to 1/4" thick in plate or flat bar sizes for cell triangles if i check once a week or so.  What size are your triangles gonna be ?  Leave a 1/4" border around the contact points PLOP gives you and you're good. So what does that end up being?.  Be careful, the PLOP triangles will NOT be equalateral's ...

CS

Bob


Edited by Bob4BVM, 15 June 2020 - 08:45 PM.

  • stargazer193857, Andy Tucker and Augustus like this

#43 stargazer193857

stargazer193857

    Cosmos

  • *****
  • Posts: 9,925
  • Joined: 01 Dec 2013
  • Loc: Southern Idaho

Posted 15 June 2020 - 08:49 PM

Currently wondering where the heck I'm supposed to get thin and wide enough aluminum for my cell triangles. If anyone has suggestions for a source that'd be great.

...


Online metals, if you want 1/8" or 1/4".

#44 grzesznypl

grzesznypl

    Viking 1

  • *****
  • Posts: 519
  • Joined: 07 Apr 2019
  • Loc: Jackson Heights, NY ... for now

Posted 15 June 2020 - 08:52 PM

I second, onlinemetals.com 



#45 avarakin

avarakin

    Vanguard

  • *****
  • Posts: 2,291
  • Joined: 13 Jul 2009
  • Loc: Parsippany NJ, USA

Posted 16 June 2020 - 11:57 PM

I get all my AL from Metal Supermarkets Fairfield NJ. They sell various cutoffs for $3-4 per pound as well as new stock for good prices too.

Prices comparable to onlinemetals but no shipping charges.



#46 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 18 June 2020 - 03:23 PM

Got my AL and sling from junkyards today. Ordered steel online.
  • stargazer193857 likes this

#47 stargazer193857

stargazer193857

    Cosmos

  • *****
  • Posts: 9,925
  • Joined: 01 Dec 2013
  • Loc: Southern Idaho

Posted 18 June 2020 - 04:18 PM

I heard scrap yards are good. I still need to go to one to find out.

There is another company similar to online metals, but similar price and less selection. There are also some places online that cost less for a few items.
  • Augustus likes this

#48 Augustus

Augustus

    Fly Me To The Moon

  • *****
  • topic starter
  • Posts: 10,043
  • Joined: 26 Dec 2015
  • Loc: Stamford, Connecticut

Posted 18 June 2020 - 07:30 PM

No luck at any of the scrap yards with steel tubing for the cell so I ordered some. I did however find a nice old seat belt which I yanked out of a '60s Ford pickup that'll be perfect as the sling.

 

Mirror arrives tomorrow.

I heard scrap yards are good. I still need to go to one to find out.

There is another company similar to online metals, but similar price and less selection. There are also some places online that cost less for a few items.

MetalsDepot, I just bought my steel from them



#49 stargazer193857

stargazer193857

    Cosmos

  • *****
  • Posts: 9,925
  • Joined: 01 Dec 2013
  • Loc: Southern Idaho

Posted 18 June 2020 - 07:57 PM

I just realised, that the heavier the mirror, the more weight trying to stretch the sling between zenith and horizontal.
  • Augustus likes this

#50 Steve Dodds

Steve Dodds

    Owner - Nova Optical

  • *****
  • Vendors
  • Posts: 607
  • Joined: 02 Apr 2007
  • Loc: Utah

Posted 18 June 2020 - 08:10 PM

I have a 18" 2" thick mirror with a 2" nylon strap and I see a significant change in collimation from straight up to horizontal, you might want to consider steel cables.


  • derherr65, stargazer193857 and Augustus like this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics