Thread: What did you learn today?

Originally Posted by KBs PensNmore

Hi Bill,
Any chance of some pics of your Rotary Turntable from an Aldi Gym Weight, or did you do a WIP please ??
Kryn

G'day Kryn,

Have a look here ( I wanted to see if I could get a tool accepted in that forum)

Manual Rotary Table

Biggest learnings (these comments may make more sense after you look at the photos)

Make everything as close fitting and tight and square as possible - - basically you are holding a handle in your hand that is connected to a Mill Motor via the rotary table, workpiece and cutter, any sloppiness will result in vibration and will assist the mill motor to grab the workpiece and turntable out of your hand or it can make the main table wobble.

I ended up cutting a couple of radial holes from the outside of the table into the centre so that I could screw into the bearing grubscrew holes and really tighten on hard from the outside instead of using tiny little grubscrews from the inside.

Made a big washer to sit underneath the bearing because there was 0.001" end play and that was making things a bit juddery and grabby.

When doing things on round bits of metal its always handy to know where the centre of the circle is/was so its handy to scratch a couple of diameters or concentric arcs that will refer you back to the original centre if you ever need to know where it was - this not knowing the location of the centre was a particular nuisance when I cut the semi circle slot for the sharpening protractor and needed to modify it. This was also an oversight when making the main table.

I ended up cutting a couple of plugs for the centre hole of the bearing - one had a raised nipple and the other a centre drilled hole - great for quickly centering the jig under the mill and the nipple was handy for plugging into a small hole on the workpiece to get the workpiece cetred on the table prior to clamping it down.

Two handles within approx 30 degrees allow you to grip with thumb and fingers in a wide grip that makes it easier to control the movement rather than a single handle.

There are a few different plans out on the internet, I improvised with what I had and copied the broad principle of the thing. Harold Hall (of course) has a detailed plan for one on his website or in one of his books.

After I get the spur gears and worms working a bit better I'd like to make a proper rotary table with a metal wormscrew driving a 40 or a 90 tooth spur gear.

Seeya

Bill

Reading this thread on the HMEM forum, it seems that the weightlifting weights are not a very practical source of cast iron .

Cast Iron Body Building Weights - Home Model Engine Machinist

Don't kid yourself When the steam engine lads get their hands on bar bell weights they often end up as wheels for the engine, tender etc. True some are just rubbish and are not worth the time taken to clean them up. Most window sash weights fall into this category.

I only have a lightweight lathe and I have used a number of quite small ones for different jobs very successfully. At the end of the day you pays your money and takes a chance. In my opinion it's worth it.

Originally Posted by morrisman

Reading this thread on the HMEM forum, it seems that the weightlifting weights are not a very practical source of cast iron .

Makes sense I guess. Why waste good metal on a dumbell. I reckon its probably one of the things sold new where the buyer wouldn't complain if it were underweight.

I think it will depend on whether it is 'proper' cast iron or whether it is just some scrap steel that has been melted and poured. The ring test sounds reasonable.

Michael

Learned that milling bits below 5mm diameter are relatively fragile frail weak things. Snapped 3 yesterday.

Learned that I can improvise a dovetail cutter from a woodwork router cutter and make small dovetails in aluminium. Didn't have a collett the right size so held it in the Jacobs chuck and doing 2000 rpm - seemed to work fine.

Getting blocks true and square on my mill is a right hassle - made some aluminium soft jaws for the vice and whizzed around the piece using X and Y handwheels them trimmed off the excess - initial results are better than the other method I tried - this one Cutting a Block Square

Dont know what I was doing wrong but couldnt get the rick sparber method to work for me.

Bill

Thanks for that tip. Now to find aluminium flat bar 12mm thick. Would make instant raising blocks at the same time.
Kryn

This morning I learned the value of wearing safety glasses.

I had been working on modifying my dust extraction system so no safety glasses were really needed.
Then I needed to turn an opening in a 150 mm PVC pipe end cap.
Approach MW lathe and put on safety glasses.
I needed to change chuck jaws so the old ones were fully out and almost off when I reached up to a shelf behind the lathe to grab the new ones and knocked a full pressure pack of Inox off a shelf above.
The Inox landed on the corner of a chuck jaw which generated a 5mm long gash in the can and it squirted up a full on jet of aerosol liquid onto my face, so it got into my mouth, nose and even into one ear as I turned my face away from the key.
A little did get into my eyes because it ran down my forehead but I managed to get to a tap quickly and rinse them.
The remainder seemed to find its way onto my clothes and when the can fell on the floor it even gave my boots a liberal coating
I just looked up the MSDS and apart from the propellant and flammability issues it claims to have no harmful contents.
My eyes did not sting even a little.

Anyway it could have been a different material.
Just goes to show.

You are so right Bob on the value of wearing safety glasses, even when you aren't expecting to be exposing your eyes to any significant danger. An unexpected result when preparing your lathe for a job, - out of the blue so to speak, and suddenly you are inundated with the contents of a pressure pack can. I'm not sure of the ingredients in Inox, but had you had Lanotec, you could have left the Brylcream on the bathroom shelf for the next few days, and still had your hair well slicked back..
Of course on the more serious note, I'm very pleased that you have not suffered any injury as a result of this accident, and I hope that the cleanup was not too difficult. Thanks for passing on your experience, it will jog our memories and just might help prevent another similar occurrence.
Rob

Hi Bob,
Certainly lucky it was Inox! The blurb on their bulk refill packs say it is non toxic and suitable for use on food machinery. Gets used for many light lube and cleaning jobs in my shop, as I find it does not thicken and go gummy as other lubes do. Also very good on firearms and we keep a small spray bottle on the pistol range as a first line defence for guns that are gumming with bullet wax and residue. With a spray bottle each of Inox and an ATF/Kero blend my shop is faitly well equipped.
Combustor.

Originally Posted by BobL

This morning I learned the value of wearing safety glasses.

I had been working on modifying my dust extraction system so no safety glasses were really needed.
Then I needed to turn an opening in a 150 mm PVC pipe end cap.
Approach MW lathe and put on safety glasses.
I needed to change chuck jaws so the old ones were fully out and almost off when I reached up to a shelf behind the lathe to grab the new ones and knocked a full pressure pack of Inox off a shelf above.
The Inox landed on the corner of a chuck jaw which generated a 5mm long gash in the can and it squirted up a full on jet of aerosol liquid onto my face, so it got into my mouth, nose and even into one ear as I turned my face away from the key.
A little did get into my eyes because it ran down my forehead but I managed to get to a tap quickly and rinse them.
The remainder seemed to find its way onto my clothes and when the can fell on the floor it even gave my boots a liberal coating
I just looked up the MSDS and apart from the propellant and flammability issues it claims to have no harmful contents.
My eyes did not sting even a little.

Anyway it could have been a different material.
Just goes to show.

your all squeeky clean now...

Originally Posted by Combustor

Hi Bob,
Certainly lucky it was Inox! The blurb on their bulk refill packs say it is non toxic and suitable for use on food machinery. Gets used for many light lube and cleaning jobs in my shop, as I find it does not thicken and go gummy as other lubes do. Also very good on firearms and we keep a small spray bottle on the pistol range as a first line defence for guns that are gumming with bullet wax and residue. With a spray bottle each of Inox and an ATF/Kero blend my shop is faitly well equipped.
Combustor.

What do you use this blend for? an ATF/Kero blend . you mean auto trans fluid? thanks

Hi, I haven't posted for awhile but have been reading the forum. I nearly took my eye out today. For some reason I decided to do a everyday job differently. Instead of holding a pistol in the vice and replacing a firing pin and spring I decided hold it in my hands. Long story short, firing pin hit me in the eye. I must admit I don't normally wear eye protection when doing the little jobs but when I'm usually working with springs I normally throw on the safety glasses.

Ben.

Ouch, I hope that you are now over the worst of it, and recovery is happening real fast,
Rob

Originally Posted by Paul M D

What do you use this blend for? an ATF/Kero blend . you mean auto trans fluid? thanks

Yes, Auto Trans Fluid.
ATF/Acetone is an excellent penetrant - beats the daylights out of commercially available things like Penetrene. ATF/Kero I imagine is a less volatile, more lubey, slightly less penatratey variant.