Go Back   IceInSpace > General Astronomy > General Chat
Register FAQ Calendar Today's Posts Search

Reply
 
Thread Tools Rate Thread
  #1  
Old 30-01-2013, 11:48 PM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
Aluminium

Gawd I hate working with aluminium!

Decided to fix my in-focus issue on the Tak FS-60C myself, rather than either spending a fortune on Tak bits, or purchasing off the shelf stuff, or getting Hugh to make me one. I already had a 56 to 2" converter (thanks Oasis!), and the short nose Vixen flip mirror, but what to do with the eyepiece...

I ascertained that I needed to lose about an inch of space - the Vixen flip mirror eyepiece holder is LONG, and I DARE not shorten it, so...

I removed the eyepiece spacer tube from the diagonal. I then unscrewed the base of it from the diagonal, and luckily found that Vixen's subcontractor used STANDARD threads. Already ahead.

I then went through ALL the adapters and extensions I had. I found an old prime focus adapter I NEVER use, checked it out, and, the Vixen base threads fit, so...

Tried the hacksaw first. I managed to make at least the pilot cuts/straight circumference lines! gawd aluminium is a pain, especially without a bench vice! So then, the Dremel...

9 cut off discs later (only shattered ONE - the rest wore down!), and about 2 hours of work cutting and I had the piece I needed. Threaded a retainer screw hole, finish sanded/filed/etc, which took a while. Acid etched it,(wonderful how HCl does not attack anodized surfaces), etch primed it, shot it with epoxy satin black paint.

It's 1 and a bit inches shorter than the Vixen spacer, so it WILL come to focus now

I could have bought a low profile diagonal, but I did this for the cost of my time, the original cost of the dremel wheels and paint, and the original cost of the afocal tube (I think it was free with my Maksutov).

I need a lathe, NOW!
Reply With Quote
  #2  
Old 31-01-2013, 09:21 AM
ZeroID's Avatar
ZeroID (Brent)
Lost in Space ....

ZeroID is offline
 
Join Date: May 2010
Location: Auckland, NZ
Posts: 4,949
You sure it was aluminium ? Hacksaw should easily whizz through that . I normally cut round objects in a 'V' block, they can't escape or move. One of those fine tooth hobby hacksaws then just a big sandng block to finish it off smooth and square, tidy it up with a small file on the corners\edges. 10 mins max. I normally wrap some tape around it to establish the cut line.

Etch and paint is seperate.
Reply With Quote
  #3  
Old 31-01-2013, 09:26 AM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
Probably was duralumin. BLOODY tough thing! There was 5mm to get through each side (I had to make the cut at the 2"to 1.25" step down ring)
Reply With Quote
  #4  
Old 31-01-2013, 09:33 AM
leon's Avatar
leon
Registered User

leon is online now
 
Join Date: Apr 2006
Location: Warrnambool
Posts: 12,781
I find aluminum a pleasure to use, but mind you need to secure it when working with it.

Leon
Reply With Quote
  #5  
Old 31-01-2013, 09:57 AM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
It is, as you say, IF you can secure it. I don't have a bench vice, unfortunately.
Reply With Quote
  #6  
Old 31-01-2013, 09:59 AM
lacad01's Avatar
lacad01 (Adam)
The sky is Messier here!

lacad01 is offline
 
Join Date: Sep 2007
Location: Darwin
Posts: 2,587
Not sure if something like pictured would have helped but I have one that I've used to cut aluminium tubing and angle, no prob. Object clamps in place and get perfect 90 or 45 degree mitres.
Attached Thumbnails
Click for full-size image (mitre-saw.jpg)
11.1 KB30 views
Reply With Quote
  #7  
Old 31-01-2013, 10:15 AM
Barrykgerdes
Registered User

Barrykgerdes is offline
 
Join Date: Feb 2007
Location: Beaumont Hills NSW
Posts: 2,900
I love working with aluminium.
I cut bar and tube chunks with my band saw
and finish in the lathe.
The lathe tools stay sharp?

Barry
Reply With Quote
  #8  
Old 31-01-2013, 01:01 PM
ZeroID's Avatar
ZeroID (Brent)
Lost in Space ....

ZeroID is offline
 
Join Date: May 2010
Location: Auckland, NZ
Posts: 4,949
Quote:
Originally Posted by lacad01 View Post
Not sure if something like pictured would have helped but I have one that I've used to cut aluminium tubing and angle, no prob. Object clamps in place and get perfect 90 or 45 degree mitres.
Yeah, the good old mitre box is an excellent option. I've even used an old tenon saw, nice fine teeth, on Alum. I think I cut all the alum struts on both my scopes that way.
Reply With Quote
  #9  
Old 31-01-2013, 03:46 PM
leon's Avatar
leon
Registered User

leon is online now
 
Join Date: Apr 2006
Location: Warrnambool
Posts: 12,781
That's true Barry, many times i have cut aluminum of all shapes and sizes using just the drop saw used for timber, cuts lovely and the blade is fine, as long as one has a carbide tips of coarse.

Leon
Reply With Quote
  #10  
Old 31-01-2013, 04:04 PM
rat156's Avatar
rat156
Registered User

rat156 is offline
 
Join Date: Aug 2005
Location: Melbourne
Posts: 1,696
I use a tubing cutter, just the business for 90 deg cuts.

Cheers
Stuart
Reply With Quote
  #11  
Old 31-01-2013, 06:15 PM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
I tried using my tube cutter, but:
1. the tube cutter I have is too small (the O.D of the tube I used is 4.5cm)
2. the wall thickness is 0.7cm

So, as you can see, a tube cutter really would have had a hard time coping with it, even if it did fit between Even a hacksaw with the tube in a vice would have taken a while.
Reply With Quote
  #12  
Old 31-01-2013, 08:45 PM
2stroke's Avatar
2stroke (Jay)
The devil's advocate

2stroke is offline
 
Join Date: Jul 2011
Posts: 816
I use a brobo coldsaw http://www.brobo.com.au/coldsaws02.html at work which cuts tube perfectly and clean, so if you had to do it again just yell out to your local small metal supplier who will probably do it for $5 if not free lol. God do i need a lathe to, but money holds me back
Good work with the drem, lol i hate using the things for cutting because of disc breaking and flying miles.
Reply With Quote
  #13  
Old 31-01-2013, 08:49 PM
brian nordstrom (As avatar)
Registered User

brian nordstrom is offline
 
Join Date: Apr 2007
Location: Perth WA
Posts: 4,374
Takahashi use good quality Aluminium Lewis , not Die cast ! .
Brian.
Quote:
Originally Posted by LewisM View Post
Gawd I hate working with aluminium!

Decided to fix my in-focus issue on the Tak FS-60C myself, rather than either spending a fortune on Tak bits, or purchasing off the shelf stuff, or getting Hugh to make me one. I already had a 56 to 2" converter (thanks Oasis!), and the short nose Vixen flip mirror, but what to do with the eyepiece...

I ascertained that I needed to lose about an inch of space - the Vixen flip mirror eyepiece holder is LONG, and I DARE not shorten it, so...

I removed the eyepiece spacer tube from the diagonal. I then unscrewed the base of it from the diagonal, and luckily found that Vixen's subcontractor used STANDARD threads. Already ahead.

I then went through ALL the adapters and extensions I had. I found an old prime focus adapter I NEVER use, checked it out, and, the Vixen base threads fit, so...

Tried the hacksaw first. I managed to make at least the pilot cuts/straight circumference lines! gawd aluminium is a pain, especially without a bench vice! So then, the Dremel...

9 cut off discs later (only shattered ONE - the rest wore down!), and about 2 hours of work cutting and I had the piece I needed. Threaded a retainer screw hole, finish sanded/filed/etc, which took a while. Acid etched it,(wonderful how HCl does not attack anodized surfaces), etch primed it, shot it with epoxy satin black paint.

It's 1 and a bit inches shorter than the Vixen spacer, so it WILL come to focus now

I could have bought a low profile diagonal, but I did this for the cost of my time, the original cost of the dremel wheels and paint, and the original cost of the afocal tube (I think it was free with my Maksutov).

I need a lathe, NOW!
Reply With Quote
  #14  
Old 31-01-2013, 10:03 PM
LewisM's Avatar
LewisM
Novichok test rabbit

LewisM is offline
 
Join Date: Aug 2012
Location: Somewhere in the cosmos...
Posts: 10,388
Quote:
Originally Posted by brian nordstrom View Post
Takahashi use good quality Aluminium Lewis , not Die cast ! .
Brian.

I am not a complete moron Brian - I would NEVER cut a Takahashi part!!! The part I cut/modified was some no-brand Chinese adapter.
Reply With Quote
  #15  
Old 31-01-2013, 10:07 PM
brian nordstrom (As avatar)
Registered User

brian nordstrom is offline
 
Join Date: Apr 2007
Location: Perth WA
Posts: 4,374
Moron ,, WHAT??? settle Grettle ,Geez Bro .
Had me worried there .
Yea Chineese Alloy is carp . Its melting point is around 370 degrees , and it clogs cutting discs and is dangerous .
Brian.
Quote:
Originally Posted by LewisM View Post
I am not a complete moron Brian - I would NEVER cut a Takahashi part!!! The part I cut/modified was some no-brand Chinese adapter.

Last edited by brian nordstrom; 31-01-2013 at 10:11 PM. Reason: Info.
Reply With Quote
  #16  
Old 31-01-2013, 10:19 PM
John0z's Avatar
John0z (John)
Registered User

John0z is offline
 
Join Date: Dec 2009
Location: Dundas, Australia
Posts: 129
LewisM,

Aluminium is easy to cut, especially if you have a bandsaw. On the subject of needing a lathe etc - it isn't quite that simple. In 2007, I also decided that I needed a lathe to do things around the house and for astronomy. Then to do a particular thing, I needed another tool or cutting bit - and now 5 years on - I realize that I have spent $7000 and still haven't quite made my first spur gear as yet, but did make a few things along the way. Right now I am restoring an old Tasco 5VTE that I picked up the other day. It needs a few pieces to fix up the mount, so am designing and making parts to make it functional since I don't know what the original parts looked like.

I could buy a lot of gear for that $7000, but I am almost there - just have to make some T-nuts and then my dividing gear will fit and I can start making a spur gear. (Soon, except that I had my calculations wrong and ended up with involute gear cutters that are a bit large - another $249 will fix that!)

-John
Reply With Quote
  #17  
Old 31-01-2013, 10:37 PM
brian nordstrom (As avatar)
Registered User

brian nordstrom is offline
 
Join Date: Apr 2007
Location: Perth WA
Posts: 4,374
Bang on John , cold cuts are the only way to go with this "Plastic Steel" .
Brian.
Quote:
Originally Posted by John0z View Post
LewisM,

Aluminium is easy to cut, especially if you have a bandsaw. On the subject of needing a lathe etc - it isn't quite that simple. In 2007, I also decided that I needed a lathe to do things around the house and for astronomy. Then to do a particular thing, I needed another tool or cutting bit - and now 5 years on - I realize that I have spent $7000 and still haven't quite made my first spur gear as yet, but did make a few things along the way. Right now I am restoring an old Tasco 5VTE that I picked up the other day. It needs a few pieces to fix up the mount, so am designing and making parts to make it functional since I don't know what the original parts looked like.

I could buy a lot of gear for that $7000, but I am almost there - just have to make some T-nuts and then my dividing gear will fit and I can start making a spur gear. (Soon, except that I had my calculations wrong and ended up with involute gear cutters that are a bit large - another $249 will fix that!)

-John
Reply With Quote
  #18  
Old 31-01-2013, 11:44 PM
brian nordstrom (As avatar)
Registered User

brian nordstrom is offline
 
Join Date: Apr 2007
Location: Perth WA
Posts: 4,374
We have 2 Brobos at work , one for cutting steel and one for Non Ferrious , eg. Aluminium and stainless .
Cold cuts Lewis .
Brian.
Quote:
Originally Posted by 2stroke View Post
I use a brobo coldsaw http://www.brobo.com.au/coldsaws02.html at work which cuts tube perfectly and clean, so if you had to do it again just yell out to your local small metal supplier who will probably do it for $5 if not free lol. God do i need a lathe to, but money holds me back
Good work with the drem, lol i hate using the things for cutting because of disc breaking and flying miles.
Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 05:43 AM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Advertisement
Bintel
Advertisement