Member postings for Dave Halford

Interesting use of a variable speed on a single phase induction motor too.

Caustic commentators on this thread must remember its Title "Spur Gears - a rogue method"

If you want to pursue the conventional route on this topic by making precision standard gears then this thread is definitely not for you - it has nothing to offer that mindset, walk away.

My examination of free hobbing is more akin to blacksmithery. The Artisan didnt have equipment to drill holes, he heated up metal and punched holes (even square holes). You would hardly have described it as precision engineering but it served its purpose. Just look at the craftsmanship in a horse shoe, note square holes and wrought square nails - dont twist and loosen. These are slightly tapered so that the thin ends curl up as they are hammered into the hoof and dont fall out - thats smart.

The pursuit of free hobbing which started with using taps - (as is done in making worm gears quite successfully btw - I dont hear any howls of disagreement on that score) and extended to spur gears has been roundly discredited for many reasons clearly explained as per foregoing posts.

And I agree - it results in a non standard form

Yet more by accident and in spite of the naysayers, I managed to produce some credible meshing model gears using the method of slitting a large bolt and this tool is currently under development , waiting for parts, and is showing promise.

I am hoping that with a more precisely made gr 8.8 tool I can predict the number of teeth I will get and also the workable distance between centers.

These rogue gears will never approach the quality of precision gears made by conventional methods and they were never intended for that purpose. I expect them to function as workable gears for light duty by a DIY method available to those with limited workshops who would otherwise never considered knocking up a gear train.

So to all amateurs, hamateurs amatures, armatures, armchairs and nearly 18,000 views, lets not resort to machinist' righteous bigotry give the Blacksmith some room maybe his tool might fly

WaM

I was proposing to use a brass shim to eliminate / reduce the slop. Any reason why not? I can't see how that nut can have become loose as there are no signs of damage on it. The previous owner was presumably making do with how it came from the factory.

but last time I suggested improvements (e.g. a LIKE button), existing members jumped on me.

Drag and Drop is not a new-fangled idea these days.

herewith photos to go with my previous posting

Hi all

Another beginner thread I’m afraid. There will be more.

After my last thread on finish I realised that I’m going to need to grind lathe tool bits. I got hold of some 20cm 10mm HSS blanks. The first thing I realised is that HSS is really hard. My hacksaw basically bounced off. So I cut it with a diamond blade on my angle grinder, but it still took ages and overheated the steel. Any tips for cutting HSS?!

At the grinder, I am lucky in that I already have an adjustable tool rest with an angle fence (used for plane and chisel blades usually). The problems I’m experiencing are:

1) It takes ages. HSS seems to be much harder than plane blades.

2) when grinding a plane blade, of course the grinding wheel leaves a small amount of curvature. But I just hone this off on the sharpening stone, through several levels of grit and then strop it for a “scary sharp” finish. But on the lathe bit, the area I’d need to hone is much bigger, and I don’t have a nice sharpening jig to keep it perfectly flat against the stone.

The result is a curved point (see pic). It isn’t possible to grind a consistent and small radius on this. The radius either ends up as “triangles” at either end of the cutting point, or a larger “saddle” shaped radius across the whole point.

I’ve watched a few YouTube vids but none I’ve seen properly address this.

I could get a bigger grinder, which would reduce (but not eliminate) the problem.

I could get a belt grinder with a circular sanding disc on the side, but I’m not sure they will be man enough for HSS.

Most likely thing is I am doing this wrong!

Any tips ?

thanks

Steve

3) I have also noticed that in order for the spindle to turn, the bolts that secure the spindle in the headstock need to be only slightly more than finger tight. Whilst it seems that there is no lateral movement on the spindle, if I pull the spindle with a little force, I can feel the headstock slots flexing. So therefore there must be very little rigidity, and it may explain The test cut I did last night, where on an unsupported pace the finish is horrible further out, improving markedly closer to the Chuck.

But if I tighten the headstock bolts, the spindle will not turn. A couple of questions:

Does this make sense? Might this be a problem?

What tension should the V-belt be? Is there any way I can measure it?

It’s a basic cheapo eBay V-belt. Is this the wrong kind of belt? I have seen a myriad of different belt types on lathes.co.uk.

I will get to the bottom of this!

cheers

Steve

For some reason when I post pics here they are rotated through 90deg anti-clockwise, if you rotate it through 90 deg clockwise then that’s how the pic should look.

it’s not an HSS blank, it’s the rear end of another tool that I have re-purposed. I have ordered some HSS blanks but they don’t arrive until Friday.