Member postings for John McNamara

HI

Solid carbide is rather brittle it needs to be brazed to a softer steel support.

As it happens I have two of Gary's holders one is fitted with the standard high speed steel tool, the other is fitted with an insert made from a piece of key steel with a square cut out of one corner along its length. I made the cut out to match a small carbide shank drill, (it was a circuit board drill very hard fine grain carbide). I silver soldered this into the cut out. I also ground the sides down to reduce the nose radius.

This created a very positive rake tangential tool that fitted perfectly into the holder.

This tool is handy for turning hard materials that High speed steel can't handle.

Regards
John

Hi

This is a slight digression from the Double Diamond tool however I did mention a Hirth Coupling. Below is a link to a calculator that gives the tool approach angle to umpteen decimal places and the height of the teeth for a given diameter and number of teeth.

A good video of making one with a fly cutter.
https://www.productionmachining.com/blog/post/video-making-a-hirth-coupling

I have not tried it yet but I think I will add this one to my list.

Regards
John
 

(Alpha version as noted by the Author)
>**LINK**

Edited By John McNamara on 05/11/2018 01:09:55

Hi All

Another variation on the theme
Ball indexing added, a kind of Hirth coupling it will be very accurate.

**LINK**

https://www.google.com.au/search?q=hirth+coupling&rlz=1C1ASUT_enAU791AU791&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi7up7-5bneAhUFNo8KHSIKAnIQ_AUIDigB&biw=838&bih=501

Regards
John

Edited By John McNamara on 04/11/2018 03:30:15

Hi All

I stumbled on this post on You Tube **LINK**

Cam at battler is an Australian you tuber that does some pretty impressive work, in this case a slotter. It would make a great series for MEW

**LINK**

An interesting shop built lathe tool, easy to make too.

Regards
john

Hi

Almost certainly sewing machine parts.

I suspect they are steel hardened and plated.

Example Link below is for a Singer 201 The classic machine found in many homes.

**LINK**

Regards
John

Hi All

Below are some photos of my 8 inch Vertex rotary table, as you can see it has 4 slots, the cover plate at the bottom is attached with 3 set screws. I cannot see a bearing however I have not removed the setting collar with set screw. I can see an inserted steel outer part in addition to the collar there is grease in the joint Judging by the small hollow centre shaft I suspect there may be a ball or roller bearing?.

The table has a Morse taper centre hole.

I purchased this table between 1980 and 1984 I know it was used in my first workshop hence the date range.

The label is not pinned on just a stick on that fell off a while back. I keep it in a drawer.

I will pull it apart when I have the time.

Regards
John

Yup a mill can drill however a drill cant properly mill.

go for a Mill.

Hi All

Stephen Gotteswinter did a series on reworking and scraping a new Vertex table to Gnats endowment accuracy on You Tube.

**LINK**

Link to a calculator for dividing using a Vertex style rotary table

It produces a simple list of the positions you can print in DEG MIN SEC as used by the vertex dividing head.
Just enter the number of divisions required.
**LINK**

I have never opened my 8" rotary table it was purchased over 15 years ago, It has always worked well for me.

Regards
John

Hmm I did a double take on that title. Obviously not made in Queensland.
Cheers

Hi Sam

It will be good to see you if you make it Sam, I will be there I m showing a new DIY CNC mill Design, the moulds are finished and I am showing them. as well as my trusted epoxy cutter grinder.

Regards
John

Hi Clive

I have been pondering.

Having just completed a certified engineered car lift design and build, actually a 5 ton hydraulic moving car access ramp I have become critically aware of the safety aspects. In this case the safety PLC and light curtain safety system cost as much as the mechanical components.

I hope the machine you have sourced is up to current safety code requirements. Does it have a fail safe interlocked safety system?

Is there any possibility of an untrained person operating it at their peril? A child for instance, or a person touching the controls while another person is under it? At the very least the controls should be under lock and key.

Moving heavy iron has to be treated with serious respect.

Regards
John

Edited By John McNamara on 03/10/2018 13:12:53

Hi All

I am working on a new CNC Mill made from Mineral castings, (10-12% Epoxy and Graded aggregate).

It requires about 250 steel inserts of various types.

Many are tapped M6 and M8. I broke an M8 tap today, annoying, I don't break taps very often. The material is the problem it appears to have hard spots. Because of the number I used the lathe to power tap the thread, it has clutch reverse so reversing out is not a problem. Had I not already machined the inserts I would have used leaded steel. It was too late for that. A 30mm thread is required for design reasons not strength so I decided to ream the holes out to 7mm yes this oversize for M8 it should be 6.7mm. The result was no more broken taps and clean threads.

I will do a write up of the mill separately

Regards
John

Rail mount to be cast in place. Note cams to position rail prior to drilling. They will also be left in position.

Edited By John McNamara on 26/09/2018 16:17:09

Hi All

Face bast...ds.

Wanted to promote the Lets make it exhibition so let my guard down and set up a personal face book page for the first time as is required to set up a page to promote the expo, then set up an event page. All good so far.

Well Face book came and went, I set up a page as required with no photo, then set up a page for the promo for the exhibition. You may be able to see it I cant.

While I was editing the info and after having passed all the intro stuff all of a sudden I was shut down and asked for my phone number "for security" or the page would be suspended. I grudgingly gave them that.

A while later shut me down again (Having paid for the promo) they asked me for a photo or I would remain suspended. Well that they cant have, not for their dastardly invasive program. if you are reading this you can see that on my terms I am happy to use a photo. What I do not want is to be face matched for life on the internet. My life is private unless I share it.

So there you have it NBG and no go.

I shut down the credit card number and await their response. There is no actual way to contact them. I got an an email confirming my add has been confirmed however I have no way to see it. as I was shut down after the email arrived with the photo demand.

And how did the 500 or so friends many of whom I have never met appear on my face book page. It clearly dug through my email as I did recognize a contractor that I only met two weeks ago there were a couple of emails to him.

Regards
John

Hi Alan

My lathe did not come with spindle taper plugs

I made two, one Morse and one NC taper at the same time. I did not use a chuck or centres.

I posted posted the method here here a while back.

**LINK**

Regards
John

Removing a raised burr on the machine table or any other metal surface is a two part process for me, first i very gently tap it down with a hammer and a small hardened and ground face steel block, This will push back some of the raised metal rather than grinding it off.

I then use an old well worn dead smooth file with the convex "belly" side against the work, used gently with your finger held directly on the back of the file directly over the burr the file will just cut the high spot leaving the surrounding areas untouched.

I prefer this method to a stone because a stone will remove metal from the entire surface it touches. If I do use a stone it will be as a last step only to blend in the remaining mark.

Regards
John

Edited By John McNamara on 27/08/2018 23:37:44

Hi

There are two clues that make me think there is a missing part. Maybe just a nut.

1. there is a round pin on the shaft that I assume engages the keyway on the outer plate.

2. There is a shiny mark just below the teeth on the gear wheel.
Could this indicate a friction clutch surface engaged there, or just the back of the outer plate. Is it relieved
engaging on the outer edge only?

It is in the right location for maximum friction torque to be applied.

Maybe the plates were simply clamped together after setting with say a wing nut or knurled nut.
Once set the only way to change the time would be to access the mechanism directly.
simple clamping is all that is needed.

Image below.
I have marked the areas in red.

Regards
​John

Hi Andy

JJ Davies Australia supply industrial felts to DIN or UK Standard.

I have no connection with them but have had good service.

>**LINK**

Edited By John McNamara on 18/08/2018 13:55:28

We are hosting an exhibition October 6-7 2018 in Melbourne Australia where I live.

Our club has been going since 1926

We are calling it "Lets Make It" Rather than calling it a model exhibition, this is in recognition of the varied interests of the members. The home workshop is changing for those lucky enough to have the space for one,

There will be plenty of models... also a fair share of high tech, Carbon fibre, Epoxy casting, CNC, Electronics, CAD Etc

Nevil Schute was one of our early members, a pioneer aviator and author I am sure if he was still alive he would be involved in the new as well as traditional model making. We need to diversify and embrace the new.

We particularly want to attract younger members. There will always be individuals who like making things. All "Makers" need to learn multiple disciplines, the multiple skills needed to fashion a raw material into an object. Let us share our knowledge with a wider audience.

**LINK**

Regards
John

Cast Iron (or Alloy Steel) castings can be made with the lost wax process.

This process will allow castings to be made with no draft as the pattern is not physically withdrawn from the mould, it is melted out.

These days 3D printing can be used to create a pattern direct from a CAD drawing, from a low melting point plastic that is melted out of the casting before the pour. Once the design is done 1 to 1 scale it is a simple matter to scale the size of the part with the cad program.

Link

**LINK**

Regards

John

Just stumbled on this 1928 book

If you google

internet archive philosophy nicholson

Old but a great reference on filing.

Regards
John