Shop Made Tools

[rcaffin]

Funny thing is that some of my CNC lathe programs are a bit like tracers, just 'different'.

Given a finished profile expressed mathematically (that is essential), I can program a tool bit to follow that shape. Then I set up a repeat loop which starts out far enough that the tool barely kisses the blank, then in successive passes I inch the whole profile inwards. (I should add that I do not use CAM; I write my programs by hand.)

Cheers
Roger

[mattthegamer463]

I often struggle to get a good dimension with a boring head, the 2" head I have is 50 thou diameter per rev and it just never seems to come out right. Decided to try a head mounted dial gauge, using a cheap 0.00005(0.001mm) gauge that works very nicely.

Turned the central bore and outer diameter on the lathe, then used the rotab to clear material to make contact points. Then an L shaped piece was made to hold the indicator. A copper 1/4-20 hex head bolt with a 3D printed handle I had lying around works as a non-marring clamp screw.

To use you bore close to the desired diameter, measure by your preferred method, then adjust the boring head using the tool by the desired diameter (-) the current diameter, / 2 as this tool measures the change in cut radius not the cut diameter. Also lets you see if there was any shift when tightening the clamp screws.

[Tim The Grim]

^^^^^^^ I like it. If you had a boring head ball turner you could dial that in too.

[Dan Dubeau]

Funny thing is that some of my CNC lathe programs are a bit like tracers, just 'different'.

Given a finished profile expressed mathematically (that is essential), I can program a tool bit to follow that shape. Then I set up a repeat loop which starts out far enough that the tool barely kisses the blank, then in successive passes I inch the whole profile inwards. (I should add that I do not use CAM; I write my programs by hand.)

Cheers
Roger

Is your control capable of using G70/1/2 canned cycles? I finger cam all lathe programs and the G70/1/2 cycles are amazing time savers.

[BCRider]

Matt, I really like the indicator holder you made there. It takes the guesswork out of the job.

I started to think that magnets might be nice instead of the handle to tighten it. But that would attract swarf and make a mess. Then I started to consider the idea of a spring loaded ball or longer travel plunger that allows you to snap it on and off instead of the need for the handle and tightening. That seemed like it might be slightly quicker and easier. Then the idea of consistent indexing the holder made me think that the spring loaded ball or plunger going into a dimple we drill or grind into the body of the boring head might be a nice idea. Just the one to go with the flat feet that form the saddle. A bit of work to form the dimple but it would ensure consistent positioning of the indicator along the axis of travel. Or do you already have something like that which you didn't mention?

[Arcane]

I often struggle to get a good dimension with a boring head, the 2" head I have is 50 thou diameter per rev and it just never seems to come out right. Decided to try a head mounted dial gauge, using a cheap 0.00005(0.001mm) gauge that works very nicely.

Turned the central bore and outer diameter on the lathe, then used the rotab to clear material to make contact points. Then an L shaped piece was made to hold the indicator. A copper 1/4-20 hex head bolt with a 3D printed handle I had lying around works as a non-marring clamp screw.

To use you bore close to the desired diameter, measure by your preferred method, then adjust the boring head using the tool by the desired diameter (-) the current diameter, / 2 as this tool measures the change in cut radius not the cut diameter. Also lets you see if there was any shift when tightening the clamp screws.

I couldn't help but be impressed by ^that^ and it got me wondering if anybody makes a boring head with a built in digital read out. Turns out they do and for at least a decade! (Poor old out of date me!) I tried to price one out but didn't have any luck with a quick search except for one site that sold a kit of 5 to do a range of bores and they were up in the three thousand dollar range/kit.

[rcaffin]

Is your control capable of using G70/1/2 canned cycles?
I am using Mach3, using NIST CNC commands or definitions.

G70: Feed / spindle override active
G71: Inch format active
G72: Metric format active

So I guess the answer is no ???

Cheers
Roger

[Dan Dubeau]

Is your control capable of using G70/1/2 canned cycles?
I am using Mach3, using NIST CNC commands or definitions.

G70: Feed / spindle override active
G71: Inch format active
G72: Metric format active

So I guess the answer is no ???

Cheers
Roger

Ah, I didn't know mach couldn't handle g70/71/72. That's a big shame. I

G71 is a Z axis canned roughing cycle. You define your cutting parameters (feed, DOC, stock to leave), and the start/end points of your finish profile, as well as the start point of your stock and it will generate a roughing cycle along the z axis to fill in the blanks, then take one pass along the profile leaving the stock offset you specified. G72 is the same, but works along the x axis. G70 follows the a profile path you define. Usually the same profile defined in your g71/2 cycle. Everything is defined in 2 lines of code, plus your profile.

I have one master program I leave in the control for most of the stuff I do (all similar shapes) and just edit a few blocks based on numbers I pull from cad and I'm cutting parts. It's a really great time saver. Maybe it's just a fanuc thing? I've never ran another lathe with a different control.

https://www.cnc.com/g70-g71-gcodes/

[Bruno Mueller]

The spindle and sliding plate is now also manufactured. I made the sliding plate so that it stands about 2mm above the sliding jaw. So it is possible to clamp wide, flat workpieces later, which do not fit between the vice jaws.

The thread of the spindle was cut on the lathe. The last 1/100mm were cut with a die.


Spindle and sliding plate. The spindle runs in a bronze bushing.




Here the projection of the sliding plate is clearly visible.

[rcaffin]

It is not so much that Mach3 and NIST cannot handle the G70/1/2 instructions: they can and they do, but following the NIST definitions of those instructions.

It would seem that CNC.com and its 'cura' programming language do not conform to the NIST (National Institute of Science and Technology) Standard, which places CNC.com in a dead-end development path. If that includes the Fanuc version, my statement stands. But then, have you seen the really weird Siemens programming language for CNCs? Very weird, and very dead end.

I hope this does not come across badly. I have been programming computers since about 1970, and I have seen too many strange dead-end languages. And I can emulate the G70 instruction you are talking about in a few line of g-code anyhow, but with greater control.

Cheers
Roger

[Bruno Mueller]

After a break of over a week, (I have renovated the living room) we continue with the vice again.
The spindle nut was made of bronze and installed. The vice jaws were made and the corresponding threads were cut into the vice. Last but not least a wrench with 10 mm square was made.
A wrench with a 10 mm square was made. For this purpose I made a 10mm square stamp out of 115CrV3 for my rotary broach.
Pre-milled and hardened. Afterwards grinded and tempered on the Bonelle Tool and Cutter Grinder.

One more small note about square broaching.
With the rotary broach You can counteract this by changing the direction of rotation every few mm. The total length of the clearing was about 25mm. The socket was shortened to 20mm afterwards, set down to 16mm and soldered into the lever arm.
I made the clearance hole with 11mm.


The spindle nut is mounted.


Square key for the vice.



Jaws with milled recesses.

[pensioner]

Once a guy I knew gave me brushless motors (BLDCs) taken from old medical equipment, and I pulled out neodymium magnets from them. Tubular magnets, 20mm in diameter with plastic filling inside. And I placed magnets from three motors on one axis and made a small magnetic block out of them for a small grinding machine.
Made the parts for the magnetic circuit, cut the steel parts as planned and prepared the brass inserts to fill the voids.

I hope the photographs show the manufacturing technology of this magnetic system for round magnets. Everything works like in magnetic stands for measuring indicators, only alternating magnetic poles are made on the plane where the part placed on the magnetic block will be attracted.

[pensioner]

And this is what happened:
Everything works as intended, but the magnets turned out to be a little weak. It is difficult to tear off a magnetized part, but it is easier to move, but I would like a stronger hold on the part shifting.
But in general, it turned out well.

[rcaffin]

What clearance do you have between the OD of the magnets and the ID of the bore?
Cheers
Roger

[pensioner]

What clearance do you have between the OD of the magnets and the ID of the bore?
Cheers
Roger

The gap is minimal, as long as it does not interfere with the rotation of the magnets, measurement with a caliper (is he in the photo) showed a diameter difference of 0.03mm ..