Author Topic: Giant binocular  (Read 3997 times)

4GSR

« Last Edit: January 27, 2019, 09:50:35 AM by 4GSR »
Ken

Carpenter84

Re: Giant binocular
« Reply #46 on: January 27, 2019, 10:35:21 AM »
Got it! Very nice.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

Terrywerm

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Re: Giant binocular
« Reply #47 on: January 27, 2019, 11:00:53 PM »
Nice work Charles! I'll be looking forward to seeing more.
Terry

Making chips with old machines!

Bill Gruby

Re: Giant binocular
« Reply #48 on: January 28, 2019, 06:42:41 AM »
 So is he. LOL

  "Billy G"
Don't sweat getting old, you'll still do dumb shit, just slower.

An Optimist will tell you the glass is half full, the pessimist half empty, the engineer will say the glass is twice as big as it needs to be.

savarin

Re: Giant binocular
« Reply #49 on: February 25, 2019, 08:33:29 PM »
For want of a shoe. OR, How I passed the last three weeks of wet.

Needed 4 chunks of aluminium for the altitude bearings for the bino.
Guess I had better cast some.
Hmm, floods and rain so better not.

so I knocked these out for the secondary mirror adjusters.
(secondary adjusters 1.jpg)
Just have to silver solder the brass nut to the brass plate, its a larger version of what I made for the tertiary holders.
BUT, my gas torch wouldnt quite get hot enough for a good joint so cant finish them off, Gaaaa.
Need a bit of brass for the remaining adjustment screws, none here, I know, cast some, oh, I cant its still raining, bugger, getting totally fed up with it so a change of tack was called for.

I had a go at turning a crankshaft, I dont have a use for it (yet) it was just for kicks to see if I could.
Got this far
(c shaft 1.jpg)
then Whoops! crashed the tool onto the chuck and snapped the belt and the parting tool. They are now on order so what can I do now?
As its still bloody raining I still cant cast anything but I suddenly had a light bulb moment, maybe I can machine down these horrible failed castings for two of the bearing blocks.
(ally halves.jpg)
I started facing off the bottom of the bowel as the other side allowed (sort of) clamping.
 The centre is only just there to help prevent it from moving towards the tailstock.   
(start block.jpg)
Then I thought why not cut the ends off with the table saw
(second block.jpg)
Now I can use the rear face of the jaws or chuck to get parallel faces then square up for the other two sides then the ends.
Many many hours later and half a ton of swarf
(swarf.jpg)
these materialised.
(finished block.jpg) 
The arrowed corner will be rounded eventually which will remove that unsightly bit then I may powder coat or polish depending upon how I feel.

From what I thought was a totally buggered up melt came the best cast aluminium I have ever poured, not an inclusion to be found. Just goes to show.
 Oh for a mill or shaper, perchance to dream.

Mind you the lathe certainly got a real flogging getting these down to size.

Ahh, the rain has stopped, the water damage has been repaired and the land is drying out.
Ta Da, casting time.
Out with the muller and prep the sand.
Not a chance, the motor has failed.
(muller.jpg)

I have a 1/4 horse I can "borrow" from the mulcher so I've cut the old brackets out ready to re build.
A major problem is the motor is rated at 2850 rpm. Thats a lot of speed dropping to get down to 30 rpm.
I can make some new pulleys and whack a jack shaft in, hang on, I need the muller for the sand so I can cast the pulleys.
Guess I had better spring for a new slower motor, found a 1/3 hp 900rpm for $140AU all up so I think thats the way to go.
They say in never rains but it pours, weve certainly had that in spades of late.
Now how do I get this purchase pass the financial controller???


Terrywerm

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Re: Giant binocular
« Reply #50 on: February 25, 2019, 10:18:11 PM »
When life hands you lemons, you make lemonade!!
Terry

Making chips with old machines!

chips and more

Re: Giant binocular
« Reply #51 on: February 26, 2019, 08:47:51 AM »
He can make lead into gold!

34_40

Re: Giant binocular
« Reply #52 on: February 26, 2019, 07:33:27 PM »
I love you're "get it done" attitude. Always forward progress.

An inspiration to be sure.
Clausing 108, Clausing 8520, Atlas Horizontal, Lincoln stick and mig welders

savarin

Re: Giant binocular
« Reply #53 on: March 17, 2019, 10:14:47 AM »
The weather dried out enough to start casting again but with no muller I couldnt use green sand so elected to try some welded moulds.
 Heres the melt with the new moulds for the bearing caps heating up on top. (altitude bearing 1a)

No pics of the pour as I didnt have any more hands available.
 They turned out very well EXCEPT----- I followed the interwebs of miss information and degassed with washing soda. Bad move, the worst case of porosity I've had. I now have more info regarding the causes so we will see what the next pours do. Check out the sprue and gate design as well. Very informative.

https://www.youtube.com/watch?v=SfTIv0hLSBs

I obtained some acetal for the altitude bearings.(altitude bearing 1)
I left it long enough to keep sufficient in the chuck to work it.
 First bored to size then turned to O/D and length (altitude bearing 2)

Then flipped it to thin down the flange that was left.
 Next I bolted the bearing blocks together and fixed them to the face plate for boring.
 I clamped them together with a 3mm length of ally between them so the finished hole would leave a 3mm gap between the halves. (altitude bearing 3)

The black marks are high accuracy depth gauge lines.(altitude bearing 4)
 
Once bored they were mounted in the vertical slide for the remaining machining.
 Here I'm using a 6 mm end/slot milling bit for the release slots. (altitude bearing 5)
and then all the corners were rounded over with a carbide rounding bit.(altitude bearing 6)

this is how they will sit on the top plate.
(altitude bearing 7)
« Last Edit: March 17, 2019, 10:16:45 AM by savarin »

savarin

Re: Giant binocular
« Reply #54 on: March 17, 2019, 10:19:18 AM »
Some thoughts-----
Do I slit the acetal so they will clamp tighter for friction? A quick test showed not for light loads but maybe for the total unit.
If more pressure is required I may have to make larger knobs for better grip.
The purpose of the slots in the bearing blocks is to allow easy fitting without having to totally unscrew and possibly loose parts in the dark. Or so I hope.


chips and more

Re: Giant binocular
« Reply #55 on: March 17, 2019, 03:29:12 PM »
Like always, you are amazing with what you make and what you have to make it with!

savarin

Re: Giant binocular
« Reply #56 on: March 17, 2019, 09:32:59 PM »
Thanks Chips thats very kind of you.

savarin

Re: Giant binocular
« Reply #57 on: March 28, 2019, 09:46:49 PM »
Slitting the acetal had a better result in that it removed all play in the bearings.
Now to make the disk brake rotors for the altitude mechanism.
I have some 2mm stainless of unknown composition and the largest rotor I can make is 235mm dia.
The largest bicycle disk rotor I can buy (buy? Thats heart attack material right there) is 203mm dia
I'm hoping the leverage at that size will allow an adjustable smooth friction resistance with an extra twist to the control to lock in place.
The difficult part is its too large a dia to fit on my lathe so I will have to go the old route before I owned a lathe, ie. the drill press.
First I used a hole saw to remove the centre then the angle grinder to remove as much of the waste as possible.
I made a mandrel from a cast billet I had to hold the disk.
Then mounted onto the drill press I got it pretty round with the flap disk then and used a hss tool bit clamped to the wooden block knudged with gentle taps of a  hammer as a feed mechanism to get it fully round.
Slow but it worked.
The top disk is a standard bicycle disk, the card is the largest dia disk I could purchase and the bottom disk is the new stainless one.
Now I have to cut it in half and pray it doesnt distort.
The matched left and right hand calipers should arrive on monday so I dont want to make the brackets for them till they arrive.

Terrywerm

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Re: Giant binocular
« Reply #58 on: March 29, 2019, 08:58:13 PM »
Nice work, Charles.  Looking forward to more as you continue with this project!
Terry

Making chips with old machines!

savarin

Re: Giant binocular
« Reply #59 on: April 07, 2019, 08:26:05 PM »
The disk cut in half with no distortion so that was good.
 So the next job was a very simple one, make a clevis assembly to actuate the caliper brake.
 What a palaver such a simple job turned out to be.
It took 5 attempts to fabricate this simple device.
The first one was a piece of 16mm stainless turned down to 6mm and threaded with the clevis milled out at the large end.
This jammed up somewhere through the motion no matter what I tried.
Various ideas around this theme also failed until I got to the version shown.
The threaded shaft is silver soldered to the small barrel that fits between the brass section so it has some play but cannot turn round.
I made a dolly of the correct size to fold the brass around.
The bracket the thumb screw tightens up against actually sits flat once its tightened to the start of the friction.The steel bracket the two calipers sit on will be bolted to the top plate.
 As a guide when assembling the bottom half of the bino I think I will chamfer a lead in on the front part of the brake pads so the disks easily slip into place.
Now the calipers are in place I can now cut the excess from the bottom of the disks.