Author Topic: The Artful Bodger tries to make something! (Read 22163 times)

John Hill · « **on:** March 07, 2009, 02:32:43 AM »

This is the rotor for my gyroscope, 520grams, 108mm diameter.

It is actually seven pieces of steel, one disc and two rims all cut from rusty 5mm plate. (four steel rivets of course).

I have also made two of the gimbal rings now I need to sort out some problems with the hub and pivot designs!

rleete · « **Reply #1 on:** March 07, 2009, 08:29:21 AM »

No fair just showing the finished product. We need step by step process pics!

John Hill · « **Reply #2 on:** March 08, 2009, 12:06:59 AM »

Time to start making some sort of hub for it..

...starting with a scrap of mild steel bar.

Roughed out with a hole in the middle...

Then turned down a bit of a rusty old bolt for a squeeze fit in the...

...hmmmmmm... not quite as firm as I would have liked but it is snug.

The first bit goes back in the lathe and one hub cheek is roughed out and ...

... parted off.

Here are the bits so far, the rotor wheel, a hub cheek, the original bit of bar used as a mandrel..

.. and of course the bit of old bolt that will be pressed in to hold everything together then sawn off. Loctite in case the fit is not really tight enough?

Everything pressed together and in the vice for the Loctite to cure.

Meanwhile....

... the first bearing cup is being parted off.

sbwhart · « **Reply #3 on:** March 08, 2009, 01:53:53 AM »

This is intreaging me

can't wait to see the finished job.

Nice to see your adding more photos John

Keep the posts coming

Cheers

Stew

Brass_Machine · « **Reply #4 on:** March 08, 2009, 03:55:43 PM »

Waiting for more

Eric

John Hill · « **Reply #5 on:** March 12, 2009, 03:52:16 AM »

The Artful Bodger gets ready to try something scarey!

I need to cut a slot in the end of that bar, the block of steel in the 4 jaw has a 'V' in it so the bar is securely located.

I have ground a HSS tool to cut the slot and tomorrow, if I can pluck up the courage, I will cut the slot, I have 8 of these to do if it works out OK.

Obviously I have to take really fine cuts but what is the recommendation, dead slow or a few hundred RPM for this type of interrupted cut?

Stilldrillin · « **Reply #6 on:** March 12, 2009, 04:38:31 AM »

Oooooh, John!

That look seriously scarey to me.

I wouldn`t dig straight in........

Can you rough out the slot with a hacksaw, before turning?

Can you rough out with a milling cutter in the chuck, & the component in the toolpost?

Be very carefull....... Please!

David.

bogstandard · « **Reply #7 on:** March 12, 2009, 05:04:51 AM »

Yes John, certainly scary.

It is not the plunge cut that will cause the problem, but the interrupted cuts. The lathe tool nose will take hell of a bashing.

I am not saying you are wrong, as you have no other way of doing it, just take your time and get ready for anything that happens all of a sudden.

It might go smooth as silk, and all our gum beating will be relegated to useless info.

Give it a go, but win or lose, let us know how you get on. Don't be afraid of failure, and boast about your successes.

John

Brass_Machine · « **Reply #8 on:** March 12, 2009, 07:25:26 AM »

As Bogs said, just be extra cautious when you are doing this.

Eric

sbwhart · « **Reply #9 on:** March 12, 2009, 07:34:16 AM »

Hi John

That looks like a brown trouser job.

Don't stand in line with the spinning job, stand to one side and slowly does it.

Good Luck and interested how you get on.

Stew

Darren · « **Reply #10 on:** March 12, 2009, 07:36:07 AM »

I'm not sure I like the look of this, that's going to be some pressure on the chuck jaws as well as whacking the heck out of the cutter.

If you were in the UK/US I'm sure an offer of help would come about....is there no-one in NZ you can turn to?

Just go very gently and slowly, though the lathe will need enough speed to actually make the cut.

kellswaterri · « **Reply #11 on:** March 12, 2009, 07:50:16 AM »

Hi John, have you thought of this set up...removing the tool post ...clamping the job to the top slide and using a milling slot cutter in the chuck to mill out the slot...much safer than trying to turn it out

...Just a thought,
All the best for now,
John

sbwhart · « **Reply #12 on:** March 12, 2009, 08:01:19 AM »

John the other John just about beat me too it. above is a Crap O cad of another way you could do it in the lathe as John just suggested.

Cheers

Stew

John Hill · « **Reply #13 on:** March 12, 2009, 02:04:36 PM »

I wasnt really scared but now I am terrified!

There is all today to think about this as garage playtime is in the evening. Thanks for the comments.

I suppose I could buy a mill cutter and lash up something to do it, I suppose I could drill 60% of the material out in advance.

Of course I could ask Sally Shaper to do this job but it looks a tall order for such a small machine and I am yet to master slot cutting with her.

However there is a certain advantage of the turning method if I can do it and that is the radius of the cut will match the piece that these slotted bits have to mate with.

kellswaterri · « **Reply #14 on:** March 12, 2009, 03:11:44 PM »

there is a certain advantage of the turning method if I can do it and that is the radius of the cut will match the piece that these slotted bits have to mate with.

John, I am some what confused,easily done these days

but how would that work?
All the best for now,
John.

John Hill · « **Reply #15 on:** March 12, 2009, 04:42:43 PM »

Quote from: kellswaterri on March 12, 2009, 03:11:44 PM

there is a certain advantage of the turning method if I can do it and that is the radius of the cut will match the piece that these slotted bits have to mate with.

John, I am some what confused,easily done these days but how would that work?
All the best for now,
John.

All will be revealed John.

John Hill · « **Reply #16 on:** March 13, 2009, 04:00:18 AM »

Much to noone's suprise I am sure but the turning project had to be abandoned.

The tool cut the end of the bar OK and although there was some chatter it was not serious. What caused me to abandon the process was that there was too much strain on the fixing in the lathe and just the slightest bit of movement there spoiled the shape of the cut.

[Besides, I broke the carefully ground tool that was exactly the width of the required groove.]

sbwhart · « **Reply #17 on:** March 13, 2009, 05:35:35 AM »

Good try John

What's your plan B?.

Stew

sbwhart · « **Reply #18 on:** March 13, 2009, 05:54:45 AM »

John Here's a suggestion for plan B or should that be plan BBB

Do it with a fly cutter held in the lathe chuck' and supported by a running centre in the tail stop, You'l have to make the tool holder but that won't be too difficult, the hardest bit will be filing the square for the tool bit, try and make the whole thing nice and stubby and robust. How deep do you want to go ?.

Cheers

Stew

Stilldrillin · « **Reply #19 on:** March 13, 2009, 09:31:15 AM »

Very good idea, Stew!

David.

John Hill · « **Reply #20 on:** March 13, 2009, 03:41:17 PM »

Yes Stew, I think that is a very good idea and not too hard to manage and I wont need a square hole if I use a round piece of tool steel.

I will loose my ability to machine a radius to fit the matching bit but maybe that can be tolerated (somehow).

This would certainly be more attractive than my (previously) current plan which was to have a hearty breakfast and break out the file chest, will no doubt do a better job too!

I had wanted to go about 10 mm but half that would be enough to get a secure fit, slot is about 5mm wide.

Stew

and of course

Maybe later today (Saturday here and a few chores to get out of the way.)

sbwhart · « **Reply #21 on:** March 13, 2009, 03:52:56 PM »

John

When you make the tool holder remember to drill so the tool is cutting on centre its a mistake

I always make when doing that sort of job.

Good luck

and have fun

Stew

John Hill · « **Reply #22 on:** March 14, 2009, 01:35:07 AM »

Bodger makes progress.....!

Fly cutter, as recommended by Stew, chops its way into the work...

Work parted off and now turning a bearing cup..

Bearing fits nicely!

Tried for size on a gimbal ring.

Doesnt look too bad, even if I say so myself!

sbwhart · « **Reply #23 on:** March 14, 2009, 02:22:34 AM »

That looks real cool

I can see what your making now John.

More More More.

Stew

kellswaterri · « **Reply #24 on:** March 14, 2009, 07:12:16 AM »

Hello John, now a litttle less ''confuddled''that I can see what you have made...very good job too...
All the best for now,
John

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Author Topic: The Artful Bodger tries to make something! (Read 22163 times)

bogstandard