Member postings for John McNamara

Hi Steve

Using the lathe could you set the wheels in the four jaw chuck and on centre in the tail stock.

Then with a jack between the bed and one of the chuck jaws, set the crank pin against the top of a bar in place of a tool set in the tool post, that would be position one.

Then rotate the four jaw and set the jack under the next jaw and move the cross slide and tool bar to the other crank pin and set the pin against the tool bar, that would be position 2.

That should get the desired angle within a fraction of a degree, chucks are pretty accurate and the lathe is giving you good axial centering.

The jack is just a short length of bar stock with faced ends machined to fit flat against the underside of a jaw and the top of the bed, handy for various marking out and machining jobs. Unless all your chucks have the same thickness jaws you will need a separate jack for each chuck.

Regards
John

Edited By John McNamara on 18/01/2016 07:09:05

Hi Steve

If the iron was in Melbourne OZ I would be over in a flash wanting to trade it for something.

Perfect for repairing antique metal fittings, It is a different colour to modern mild steel particularly after a light etch and rust to bring back the nice grainy striated pattern and texture.

Regards
John

Hi Grant

I have a (Chinese) two ton engine crane, the type that has two legs that form a V when down and in use and fold up.

Similar to this one http://www.manualhandlingsolutions.co.uk/images/FOLDING_WORKSHOP_CRANE.jpg

It has been a very handy machine around the workshop however it is not very laterally stable, the legs are not wide enough and the Jib is rather flimsy.

Working on concrete it is OK although I always find using not without some trepidation. I would be most wary of using it on bare earth, it might topple.

When I use mine I use it for straight up and down lifting. And never try to push it sideways with a load suspended high. Sometimes you have to move it back from say a bench or the back of a truck to allow the load to clear, but as soon as the load is clear I drop it down as near as possible to the floor. Only then do I try to push the crane around to move the load. The lower the center of gravity for the crane and load the better.

Oh, And never ever allow any part of your body to be under the load or near a crushing point should it let go.
These cranes would never pass a crane inspection for industrial use. Used carefully they are a great help however we must be aware of their limitations and there are many.

Regards
John

Edited By John McNamara on 27/12/2015 06:05:46

Hi All

Merry Christmas, a time to relax with family and friends.
And maybe a bit of time in the workshop, trying to work of that extra slice of Christmas pudding.

Regards
John

H Francis IoM
Sorry you had trouble with my post.

I used google searches instead of direct links for a couple of reasons.

Direct links can fail at some future date due to a page being moved or deleted.
There is so much material available on the net attributed to this man, a name search will always find the latest material posted.

I am surprised the links did not work properly for you, I tested the links directly from the MEW site after posting to make sure they worked. I could have posted the search terms as well, although these days most people can read the Link and work what was used.

The searches were

Arvind Gupta

Arvind Gupta pdf books

Regards
John

Hi All

I stumbled upon this man Arvind Gupta by accident while searching the net
Here is a Scientist educator that likes making toys and a lot more......

In a word amazing.

This is an area that interests me, a good use for the CNC router and workshop, quality toys that can be made quickly at low cost and shared.

General search
**LINK**

PDF Search
**LINK**

It Is Christmas, A time for good cheer getting together with friends and family.

Can't this thread be allowed to disappear into the abyss that lessor value posts descend to in this case preferably at a very low level?

Education and literacy do not necessarily travel hand in hand with being smart. Education is no guarantee that a person is a compassionate and caring citizen or a good craftsman. History has recorded numerous illiterate but great men and women. Anyway this forum is about Engineering it is not about English literature criticism.

I am making a new year resolution. I will not post in this thread again. Let it pass across the Styx to the place where it belongs.

Regards
John

Fusion works fine on a Mac there is a special version for Apple computers, A mate uses it on a Mac and is CNC cutting parts with it.

The CAM abilities are really what got me excited about Fusion. It can import many different file types.

**LINK**

I was able to import a 3D solid model written in Autocad straight into Fusion then create G code using the CAM functions.

See link below Look down the page a bit
**LINK**

For CAM... Direct to Mill or 3D Printer.
If you already have a CAD program you like working with and it has a compatible file type you can use that until you have learnt to use fusion for drawing in 3D.

Regards
John

Edited By John McNamara on 14/12/2015 22:37:10

Learning CAD from scratch is never a doddle, It takes a certain amount of work, well worth the effort in the end. Whichever program you choose make sure there is a strong user base and active discussion forums and Video to get you over the hurdles that will pop up. The miracle of the internet and Video from Youtube and others makes a huge difference.

Think about your current and future needs when deciding upon a program. Unlike say a word processor CAD programs are all different. Switching is not easy, I know.... as I work my way around Fusion 360 It works differently to AutoCad I know well. Relearning can be harder than starting from scratch

Regards
John.

If you have the room on your mill a 4 jaw chuck mounted on the rotary table will cover most of your work holding needs.
Using a dial indicator you can center up a part perfectly. the same way as on the lathe.
By reversing the jaws you can even cheat a little and work over the edge of the rotary table itself.
Odd shaped parts are not a problem.

Make sure you get one with the correct number of through hole mounting points designed for front mounting on a face plate for your particular rotary table.

Regards
John

Hello Paul Jameson

You mention you intend to "build my own oxygen absorbtion machine" That sounds like a very interesting project, Can you elaborate on your design please?

Regards
John

Hi Bob MC

Have a look at fusion 360. It is free for Hobby use.
There is plenty of Youtube videos that will get you started.

It can create Gcode for mills and routers (Laser is under development)
Or create files for 3D Printing

Yes you can make 2d paper drawings too.

Link to thread in this site

**LINK**

Regards
John

Slam weld? typo! I should have said small weld.

Hi David

If your lathe has a fixed steady big enough to fit around the cylinder itself you could centre the cylinder with a 4 jaw chuck gripping the best of the two shafts first then turn the other down and fit a sleeve to bring it back to size. repeat for the other end if needed. You would need a dial indicator because moving one end affects the other you have to keep checking both ends until both ends are centred, it may take a few iterations to get it spot on.

If the fixed steady is not big enough you could make a small cat head, in this case a steel cup with a clearance hole to fit over the end of the roller shaft drill and tap the edge of the cup at 90 degrees for 4 set screws maybe around M8 would be good. centre drill the cup. Maybe a cup depth of say 20mm and a wall and end thickness of around 10mm. The cup can be slipped over the end of the shaft and the cylinder centred on the tailstock. The roller proper can be trued up with a dial indicator. then the cylinder and the shaft can be trued (Except for the bit under the small cup maybe 20mm). to finish the last bit remove the cup and set up the fixed steady on the now true shaft and finish off the last 20mm.

Repeat for the other end.

Because of the stresses set up by the welds the shafts may move after part of the weld is removed. To be certain the process above maybe better done in two passes. leaving a few thousandths for the second pass.

When you weld a piece of metal the white hot pool of metal expands and is then rapidly cooled by the surrounding metal creating an area of tension. the tension can be equal to the tensile strength of the metal itself 40 to 100,000 PSI, even a slam weld can bend a thick shaft or plate.

Regards
John

Sounds Like Hard rubber?

Often patchy grey black

**LINK**

Regards
John

Usually referred to as a Schrader valve tool

**LINK**

Regards
John

Hi TM

Oil wicks and Pipe cleaner like twisted fine wire with a loop at one end to thread a wool or cotton yarn through drilled holes are a common method used to carry oil to the bearing surfaces of industrial sewing machine heads it is still used to this day.

The system works remarkably well. Capillary action doing work, drawing the oil through the machine.

Make sure the wicking thread touches the larger felt pads and only the wick not the soft iron fine wire touches the bearing surface. try to replicate the old system.

Regards
John

Hi Velo

Home page for KB

They have manuals online.

**LINK**

Regards
John

Hi TM

Sounds like you have an interesting machine? I could not find a reference to it on the Lathes.co site.

Can you post a picture or two?

Regards
John

Hi Rainbows

Bearing design is part art part science.

This is a fairly easy to read get you started paper.

**LINK**

or this Google search

**LINK**

Regards
John