Member postings for Dave S

Spade drill is the way to go for that sort of size.
If you can make them from carbide so much the better - it’s stiffer.

PCB drills are another option that works well

edit to add photo, Lego man for scale:

Dave

Edited By Dave S on 06/11/2021 18:13:29

The problem with prop 65 is the list of things on it is so big and the chances of being sued in californium is such that it is easier to put on the warning than it is to try and determine if it actually has any of them in.

the list also changes frequently…

Dave

If you use inserts look at the recommended feed per rev and start there.

When not screw cutting my lathe is usually set to 3 thou per rev IIRC - it was the feed rate of my most used insert tool.

Dave

A jewellers bench peg will clamp onto any decent table, and is the correct thing to use to support thin metal when cutting it with a jewellers saw

Dave

Evening all,

I recently bought a Deckel S0 grinder. It came with 3 wheel adaptors. 2 of them are Deckel ones (one was on the machine and one of the spares matches)
The third one is a mystery - it doesn’t fit the Deckel spindle.

Can anyone ID it?

The Deckel one is on the left, the mystery one is longer and has a thread on the wide end of the taper

Mystery taper is about 17mm at the wide end

Wheel nut is about 35mm dia

Flange to wide taper end face about 28mm

Suspect it might be for a Chinese Deckel clone, but not really sure.

Dave

Why did you use moly grease in the first place?

IIRC moly is an EP additive, for use when there is considerable pressure and the lube film may break down.

I would think a quality lithium grease would be fine.

Dave

With Jewellers saws blades, especially for the smaller sizes, just looking at them wrong causes them to snap

I have used both Super Pike and Platinum King (and also Valorbe) blades, and I (a somewhat experienced operator) get better results in Stainless (and Titanium) with Platinum King blades. This will of course be down to various conditions such as the actual alloy, the saw frame, the operator etc. FWIW the Super Pike blades seem 95% as good as Valorbe ones for less than 95% of the price.

On a 'real' hacksaw I use full hard blades - I found that bimetallic ones seemed to stretch and loose tension, with the result that the cut tended to wander more. Yes they are more likely to break if you 'twist' the frame during the cut, but you shouldn't be doing that anyway....

Hacksaws get their 'set' from the wave. I think this is mostly because the teeth are small, so setting individual teeth like on a woodsaw is impractical. I have had a big, course power hacksaw blade with individually set teeth, but most are wavy. Jewellers saw blades, at least in the finer sizes don't have an set that I've noticed.

Most junior hacksaw blades seem to be a bit rubbish - they are very soft, and the spring frame and soft blade inevitably leads to wandering cuts. The handles on most junior hacksaws don't help their either.

Dave

In general saws which just have a spring frame are better setup pull cut.

My junior hacksaws are set to pull cut.

A “full size” hacksaw has a rigid frame - so push cut is fine.

Jewellers saws are best used sitting down with a bench peg and the saw handle at the bottom, blade vertical.

As with all manual skills there is no escaping the need to practice. If you want to cut things straight and fast without putting in the hours at the bench you need a machine.

Dabe

Mark,

sort of depends… if your hobby is machine tool rebuilding (seems to be from long observation ) then rebuild it properly.
If you are going to sell it I would think there are other machine tool rebuild hobbiests who would love to start from a known state - clean but worn.

Your unlikely to make money rebuilding it, and I suspect it’s just as saleable in honest known clean but worn condition.

The most objectionable thing about “rebuilt” is that they are generally “cleaned and made to look good” - it’s a morally ambiguous position - one mans rebuild is another mans slapped some paint on it

<warning massive generalisation ahead>The dealers are generally trying to make a buck so don’t spend more than they can get back, which leads to a description that is more positive thought than practical rebuilding.

Dave

PS how much?

Saw blades from Cookson Gold. Make sure you get the correct size - you want 3 teeth in the cut.

For lubricant plain old beeswax is as good as anything - although I tend not to use anything most of the time - the swarf is fine and tends to gum up the cut when a lube is used.

Dont saw fast, a gentle, slow stroke is best, with minial pressure - the saw should the 'thought' along for want of a better way of describing it - almost meditatively.

The simple answer is you need more practice.

I’ve never seen deeper jewellers saw blades.

I have had better results on stainless with Platinum King blades than with Super Pike ones.

Dave

White spirit is not cellulose thinners, so I just that part is true

Dave

This may be useful:

Using laser cutters

I work at Kitronik

Dave

Edited By Dave S on 30/10/2021 18:23:57 - fix the link

Edited By Dave S on 30/10/2021 18:26:37

From your new picture, assuming the front/back faces are parallel, I would clamp dial in the milling vice with enough sticking out to be able to cut the slots.

Cut 2 slots. Then cut 2 lengths of a bar the same level both and long enough that when inserted into the slot they will touch down on a parallel without the part rocking. Ensure that they don't protrude past the face.

Then setup the part the other way up in the vice on a suitable parallel (thus indexing 180) and cut the second pair of slots

Dave

What do you want to know?
We run 4 at work, and I know a very good laser guy - Dominic @ Smoke and Mirrors

Dave

Never had a cutter shift in a properly done up ER collet. I have forgot to do them up but that’s a different problem.

I use ER16 on my Unimat, which predates me getting a mill, so I bought an ER16 chuck for the mill when I got it.
It’s an INT40 machine - TOS FNK25 so a bit larger than the typical hobby machine.

The other size i use is ER32 in the TOS, and in various fixtures like the Stevenson Spindexer for instance.

The tightening torque spec is quite large iirc, the ER32 hook spanner I use is about 18” long.
Do em up properly and I don’t think you’ll see a cutter shift

Dave

Do you mean a taper turning attachment or the top slide add on?
Ive not seen a taper turning attachment (like on a larger lathe) for a Unimat, so that would be interesting.

Dave

Looking good. Biggest improvement I made to my Unimat 4 was fitting brass gibs.

Dave

This:

is a roller filing jig for a lathe.

the 2 rollers guide the file in a linear manner. Traditionally they are used with a head stock division plate to file squares and other polygons onto the end of round stock.

Squint a bit and refer to my sketch and you will see how to make such a thing.

However Robert is correct - use a machine to do the job

Dave

2 or 3 angle plates and a pair of rollers. Set the whole lot on a flat surface. Adjust the rail to give required size, push up against angle plate to give squareness.

Sketch appears to be at 90 degrees to the intention.

Dave