Member postings for Dave S

Cookson do a good selection. I have a Super Pike selection set I bought from them. This one

I generally use the Vallorbe 8/0 for most of my other stuff (watch dials and hands) and the platinum king ones for steel - usually 2/0 for the thicknesses I’m cutting.

Dave 

Edited By Dave S on 02/02/2023 18:54:04

The reason for using a cone drill was the size of the curve could be got correct by the correct depth of drilling, *and* the cone automatically adds the required relief to the cutter.

Made a few that way.

Dave

I’m away so can’t look it up, but I’m pretty sure the calls are in Ivan’s book.

The diameters relate to the number of teeth and the module size.
I seem to remember it’s something like number of teeth + 1 divided by the module, but that might be pitch centre or totally wrong…

Dave

I would also say valve spring compressor. I have one a bit like that which did actually start out as a g clamp....

Dave

I disagree. The reason for using a centre drill is to put a centre in the end of a bar without having to use 2 (pilot and cone) drills. A spotting drill is exactly the correct drill to spot a drilled hole. They have very short flutes, often made of carbide, and no centre pilot tip to snap off. At least as stiff as a centre drill.

Spotting drills don’t create a 60 degree cone, but rather a more correct cone to guide the following drill. The centre drill cone doesn’t really guide well, as the corner of the cone can cause the lip to dig in and push the drill off axis

Youtube machinists seem to get this wrong, and a large audience follows them.

I have used a centre drill to spot, but then I doubt I am alone, at least I know it’s wrong - rules are for the obeyance of fools and guidance of the wise

Dave

Pimoroni do this nice looking set:

https://shop.pimoroni.com/products/combination-spanner-set?variant=30261559558227

Dave

Can’t comment about the evri thing, but last week I returned a dry suit ( other hobbies) using Parcelforce 48hr tracked service and it wasn’t delivered to the company until a week later.

It should have missed the strikes based on the dispatch from me and the 48hrs, but it just sat in a depot after collection from the local post office.

Dave

When I did the kitchen worktops in our old house I used granite floor tiles. I still have some off cuts in the garage.

That same kitchen also had porcelain floor tiles as it happens

Both tile types were roughly the same thickness, around 15mm

I can tell you that the granite tops looked spectacular, and were *considerably* cheaper than getting a kitchen fitter to put in a “solid” granite worktop.

The floor tiles had a perfect reflection, so were quite flat, but I wouldn’t like to use them as a surface plate - too thin.

4 strokes often have separate valves, 2 strokes often use the piston as a valve - via the ports in the cylinder wall.

The piston top on a 2 stroke might have features to help retain the mixture and swirl it - like a 'wedge' shape. I dont think 4 strokes do.

Dave

IIRC, and its been a few years....

The spindle had a pulse generator on it, which was fed into a box of electronics.

That electronics did pulse dividing, which generated the step signal to drive a stepper motor which was attached to the input shaft of a sodding big dividing head.

It was a Victoria universal horizontal - so the table could be swivelled to match the hob angle I think.

There are pictures somewhere, either here or over on the homeshop machinist bbs

Dave

Vetus are what I use, and they are good enough for very small precision work:

That’s standard 0.1” veroboard I deadbugged for a prototype. I also use them for watchmaking. Normally use number 3 shape, but also use number 5 for really fiddly stuff

Dave

3 points of support define a plane unambiguously.

Starrett plates have the 3 points marked during manufacture to enable the end user to support the plate as it was made. This removes potential changes because of the supports.

The bottom of my plate ( and I imagine many other Chinese plates) is not marked for where the supports should go. It is however quite flat, so I figured a flat thing on a flat thing is probably ok. The top surface checks out too as flat as I can reliably measure in an un temperature controlled garage so Im happy with it.

Dave

I cheated for my main use surface plate - It is sitting on a 4'x2'6 cast iron surface table...That plate is a 450x450 granite one. It doesn't have support point markings, so I figured that supporting if on a flat was the best thing.

My 2'x2' Cast iron plate (I use it as a welding table) is on a fairly weedy looking stand made form 1" box section. That supports the plate on its 3 feet, with additional 'anti tip' supports just off touching (like a feeler gage off)

Dave

6mm deep is only 2.5 diameters. That should be fairly straightforward.

it’s likely the problem is at the start of the hole. Once a drill wanders it is very unlikely to self correct.

56 holes is worth a little effort in jigs.

A top hat drill bush carefully made - bore the hole to a tight sliding fit on the drill, face the end in the same setup to ensure squareness and the harden fully, maybe temper to straw. Clamp this to the bar and it will ensure the start can’t wander away.
You don’t say the spacing between holes, but the drill bush can also have a pin to drop into the previous hole to give you simple accurate spacing.

I would be tempted to purchase a good quality solid carbide drill - not for the hardness, but for the stiffness.

Dave

I just used a normal single phase motor and a steel disk. I load it with 7 micron paste to polish:

You can see the motor in the background

Dave

Edited By Dave S on 29/10/2022 20:42:13

The late JS used to repair these by filling the slot with weld and remachining it.

I think there are some photos and how to over on the home shop machinist bbs. Might also be something here in the Bodgers Corner thread (think that’s what it was called)

Dave

I’ve never really worried about the size of a machine. I started with a Super Adept, quickly followed by a Unimat.
This then became a Harrison L5, which was about the capacity of lathe that seemed “right”.

I had a shaper, but then accidentally bought a much bigger mill than intended - I was after about a Bridgeport size, but a TOS FNK25 came up cheap. It’s 1700kg.
That was followed by a J&S540 and then I swapped the L5 for a CVA - basically the same size but much better at keeping the floor from blowing away.

The only one that I didn’t move initially was the TOS - the place I bought it from was having some other machines moved so 100 quid got the mover to drop it off at my door

Dave

Whilst it needs to end up as mt2 (probably) it doesn’t have to be mt2 whilst fixing it.

I would bore the spindle to a suitable cylindrical diameter (probably large end of mt2 ish)

Then loctite or shrink fit a plug in and finally bore and ream that using the spindles own bearings.

Probably worth replacing the bearings whilst your doing it - modern new bearings of reasonable quality are not expensive and are sufficiently accurate for the job.

Dave

Silver steel is normally sold annealed, then hardened after machining.

however if hardened can also be drilled using carbide drills.

How deep is the hole, or is it cross wise?

Dave

Try here:

**LINK**

Dave