Thread: Your latest project

Hi Nigel,

A friend of mine uses a MGEHR 2mm holder on his CNC lathe for parting off material. Currently HEX 316 stainless bar. Drilled and threaded both internally and externally for high pressure fittings. An insert only lasts about 30 cuts.

Race bikes have no stand.
I made this portable one - mainly for taking the bike to scrutenering, or hold it up while I get the “big stand”
It has plastic pipe inside, and slips over the footpeg.

And, the next project - Belt sander kit. (I’m not much chop at inserting pics, in the right place!)

Actually factory neighbour's. He is making a machine to centrifugally cast pistons. This is the base, and the start of the box which will hold a gas ring burner to pre-heat the dies:
IMG_1729.jpg
A really interesting project that many people in my complex are helping out with (CNC guy for the dies, stainless kitchen fab'r for the heat box, me for floor space and occasional tools and crazy ideas )


The two plates had some large holes cut for the shaft and slip sleeve. I turned them up into large washers:IMG_1730.jpg
Small one machined as expected (dull with some slight juddering).
Large one? Looks like the tip became blunt – as the long tight spirals of swarf were bright blue – but a nice finish from mild rolled steel !

Having a crack at making a larger diameter fly cutter

Didn't have a end mill long enough to clear the pocket. So I pilot holed the carbide seat then flat pointed a drill bit to get the reach

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That's a BIG Fly cutter Ajax01, what is the diameter ?. It looks like your making it out of an old car engine flywheel.

You'd be right that is a car flywheel. Using the seal area of the crank shaft as a mounting boss for the arbor.

I'll measure the OD in the morning

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250mm

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Originally Posted by BaronJ

friend of mine ... MGEHR 2mm holder ... only lasts about 30 cuts.

That is helpful to know - on big/hard material I may have to always start with a fresh insert

Today, was tempted to buy a CBN insert: https://www.aliexpress.com/item/1005001826855988.html
but decided to use up the cheapies I already have, and then maybe try some MGGN with decent positive rake.







Yesterday's project. A tool post locating sleeve for the Hercus.

The QCTP block just has a washer and M10 cap screw to bolt it in place, so got some inch round, drilled thru at 9.5mm, bored to 9.7mm-ish (to just clear the M10 fastener), and started to turn down the sleeve diameter:
IMG_1749.jpg

A pleasant hour's machining. Hardest part was aligning the round on the very tip of the chuck jaws.
When I did final sizing, took the QCTP block off to see if it would just slide over the sleeve,
and foolishly realised that the block already had a sleeve on top:
IMG_1750.jpg


So, now I have a "tower of Hanoi" or "Matryoshka doll" of locating sleeves
IMG_1751.jpg

1. I got a little frustrated by the height of the set screws in my QCTP holders – they were sometimes getting in the way – so I bought some shorter ones to replace them.
(M8-16mm from: https://www.aliexpress.com/item/4001346922420.html )

Of course, the existing screw's heads fit in a 7mm square hole in the tightening tool, and these new M8 square head screws are 8mm square.

A sensible man would have roughly ground them down on a bench grinder. A bored machinist would have found a jig to do the same. Me? I found some V blocks with M8 holes in them, did my best to align the square sides in a row, and milled them down by about .35mm on each side:
IMG_1754.jpg IMG_1753.jpg IMG_1755.jpg

Turn them around by 90°, mill the other two sides, and the tool just fits:
IMG_1756.jpg


End result, and fitting:
IMG_1757.jpg IMG_1758.jpg



2. Cut a strip of 3/4" plywood, take some hardware:
IMG_1760.jpg

drill some random 7/8" holes:
IMG_1761.jpg IMG_1762.jpg(oops - that went too far thru)...

and voila:
IMG_1763.jpg IMG_1764.jpg

Some of the blocks in my clamp set have defects, which annoyed me last time I used them, so time to do some fixin.

Mostly just wear and tear that I could attack with a triangular file,
but the top two look like they weren't stamped properly in the factory:
IMG_1766.jpg
and I wasn't going to spend many hours with a little file. Time to practice some milling!

An ER16 threading tool should do the job...
IMG_1767.jpg


but the hardest part is holding the job. Another stepped block, and some spacers:
IMG_1768.jpg



I put a sheet of white acrylic behind, to diffuse the light from yonder window, and make a poor shadow box:
IMG_1769.jpg
and had to put another parallel in there to get clearance for the correct angle; vice angled at 40°ish seemed correct.


I just guessed the height and depth. Did an OK job on the two mal-formed steps:
IMG_1770.jpg



Now for the other one, which needs all its steps re-cut. I'll try clamping the bottom and hanging it further out, which necessitates a different cutting tool:
IMG_1771.jpg IMG_1772.jpg

but that didn't work - triangular boring bar won't get far enough in, and don't have a dovetail cutter. So, borrowed a different boring bar:
IMG_1773.jpg IMG_1774.jpg


Also upped the mill spindle speed. Test cut went OK:
IMG_1775.jpg
but it sounds like a machine gun in there



Hardest part was working out the step offsets. A vernier over 10 steps seemed to be 30mm vertical, so I tried 3mm each one. Block is 60°, so Y step should be (tan60)/3mm? Nope. 3mm seemed too tight - when checking against another block, it would ride up as I engaged on more machined steps, and 1.7mm is too much horizontal step.

IMG_1776.jpg

Then I re-measured my "reference" block, and it seemed 10 steps was 27mm. Hmmm.
How could I have stuffed that up so badly?
...hang on, that would make it even worse. 2.7mm vertical would be even tighter.
Did I take into account the 10° slope? Yes I did. Still 27mm/10, but test fit needs 3.06mm?
Hmmm. Surface plate?


Stuff it. Getting late. Where has the day gone. I'll just eyeball it, while light is still shining through my improvised shadow graph. I also realised that the bottom 3 steps would never be used, so didn't bother re-setting vice and clamps to cut them.


IMG_1777.jpg
End result fits OK, and in my mind, this was faster than filing out 12 little steps

OK, not really a refurb, just adding some missing parts;

1. The chuck is missing a key, and it is an odd size – 7.7mm square – so I had to make a key.

• Found some mystery steel that someone had partly turned down (to make a bolt?).
• Put in the lathe, machined the tip down to about 10.5mm round, with some chamfers.
  It machined nicely, so I think it might be 4140.
• V block, vice clamped vertically in the mill, cut 4 flats by eye, just using verniers for sizing.
• V block on bed, drilled through head.
• Attempt to flame harden the tip. Clamped in bench vice, heat tip up with butane torch
  (past straw, and blue, to what I think is reddish),
  grabbed with pliers and put under dribbling tap for a few seconds.
  Then do a second, slower, heat/cool cycle.
• File out hole to fit a random bit of rod for the handle. Try to hammer through, but it gets stuck.
  Try to hammer it back out. Still stuck. Make some nasty vice marks on it while trying.
  Have to drill it out and re-file to make it larger.
• Back in lathe. Polish out some vice marks:

IMG_1778.jpg

• Shove rod handle in. Now too lose. I put some spring steel shim stock in there, to wedge it in.
• Out in the sunshine with a very fine little file, to polish a few burrs.
  Am pleased that the tip does seem a little harder than the body.

IMG_1779.jpg


It fits perfectly in the chuck:
IMG_1780.jpg



2. The grinder is missing a little eccentric connecting rod:
IMG_1781.jpg


I've purchased a manual, which has a diagram, but there are no sizes, so this will be a lot of experimentation

G'day,

I have a Spiramax drill grinder that looks remarkably similar to yours.

I don't have a parts manual for it but do have a copy of the original operating manual that I am happy to scan and send to you if you wish.

If it helps, I am happy to take pictures of the parts you need or remove them from the machine and send them to you to copy.

I did try to upload a picture of the grinder but this site is obviously smarter than me. LOL

Let me know if I can help.

Jacko

Originally Posted by pcx

If it helps, I am happy to take pictures of the parts you need or remove them from the machine and send them to you to copy.

Jacko, thanks - that is incredibly generous.



Before we go that far, we should check they are identical. If you take the crank handle off, and then the cover, you will see 3 gears.

1) Mine has a 1/2" rod coming out of a lever, clamped to the middle gear's shaft:
IMG_1781.jpg
but I'm not sure that is original, because the purchased manual seems to show:


2)
IMG_1794.jpg
a thread in the lever, that a bolt (48) with a swiveling sleeve? (47) fits into.



P.S. The manual is for ZB25 and ZB32. ZB25 is meant to fit a 1" drill down the spindle,
but I can only fit a 7/8", so I assume mine is older than either of these models.

1) Many years ago, I broke the zinc casting on the base of my $99 drop saw. I coped with a fabricated version for a few years, but eventually found a similar one on the side of the road. It is just a little too large, so some quick machining is needed.

First, a slot so it can sit closer to the rear bracket:
IMG_1788.jpg IMG_1789.jpg

Second, make the base flat. Was too lazy to crank the mill head down, so I just stuck it out at its limit, and moved the cutter out a little in the collet:
IMG_1790.jpg IMG_1791.jpg IMG_1792.jpg
(had to get a bit creative with the clamping and shimming)

End result:
IMG_1793.jpg



2) Some mystery metal - a large cast disc. Wasn't sure if it was iron or steel. Best way I could discern was to do some machining, and "read the tea leaves". Started facing off the cast surface with a TCMT 110204. Face wasn't very flat/true, so an interrupted cut. Lots of vibration.

The chips started very small, but had some curve to them, so I'm guessing some form of steel.

Decided to finish the job (i.e. face it flat), but nearly 5mm of interrupted cut needed near the outside. Tried a few different speeds. 200-300rpm cut OK, but at 180mm diameter and slowest auto-feed, it was going to take all day. 500rpm was vibrating too much - I could see the toolpost wobbling a lot, and the hard casting surface was making sparks.
I decided to push the (cheap) carbide to see what it could do, so tried .1mm or .3mm DOC dry, and then tried coolant. First few cuts gave me a nice shower, until I got the flow rate just right - fast drip in the middle of the insert. Found that manual feed worked better than slow auto. Varied between .1mm and .9mm DOC, but when it was close to being flat near the outside and I decreased the depth, realised that the tip is worn out, as it was pushing a lip of material toward the centre of the face.

Anyway, I will look closely at the tip in Monday's light, but thought this stalagmite of shavings under the tool was worth photographing
IMG_1795.jpg

My grinder is the equivalent of the ZB32. It will grind up to 32mm or 11/4.

IMG_2156.jpgIMG_2162.jpgIMG_2164.jpg

Some measurements I took are

Gearbox width 215mm outside to outside.

Small gears in the gearbox 51 tooth 53mm od.

Large gear 105mm dia. approx. Haven't tried to count the teeth. I will if you need it.

The arm on the center gear is a bit different to yours but I don't think that is significant. The throw is approximately 23mm. It has an 8mm thread in it.

The connecting arm is 96.8 long with 2 8mm bore bearings in it on 73mm centers. However this grinder came from a TAFE college and looking at this arm I think it might have been made in the college.

Please let me know if any of this helps and the offer stands.