Member postings for Steve355

The chuck is relatively speaking new and looks to have a good grip on the piece, and it seems well seated in that if the bolts are removed it is still difficult to get the backplate off the chuck.

I do think the you and an earlier poster may be on to something with the headstock alignment though. Everything else on the lathe was out of alignment , no reason why the headstock should be accurately aligned. It’s actually the only part I haven’t messed with so far. The spindle has a 1MT fitting. Is it worth me investing in a 1MT alignment bar? They don’t look to be too expensive, but are usually quite short. I’ve used of all my other stock messing around recently doing test cuts.

Steve

The chuck is relatively speaking new and looks to have a good grip on the piece, and it seems well seated in that if the bolts are removed it is still difficult to get the backplate off the chuck.

I do think the you and an earlier poster may be on to something with the headstock alignment though. Everything else on the lathe was out of alignment , no reason why the headstock should be accurately aligned. It’s actually the only part I haven’t messed with so far. The spindle has a 1MT fitting. Is it worth me investing in a 1MT alignment bar? They don’t look to be too expensive, but are usually quite short. I’ve used of all my other stock messing around recently doing test cuts.

Steve

On the bed there are a few nicks along the edges, and some wide circular grinding marks that look like they are from the original manufacture. It looks in pretty good nick overall.

Thanks for all the comments

when I remeasured my work this morning the taper was back 😢 no idea how but it clearly is

So I thought I would try what several have suggested and turn a new piece of brass rod without tail support and try shimming the tail end to get it parallel. So I did that…

my first measurement was 935 at the headstock and 961 at the far end. I added shims tightened it back up and took several more cuts and measurements.

now I have quite a lot of shim (about 030) and my level (love it or hate it) indicates a significant amount of twist that wasn’t there before. Headstock:

tailstock:

shims :

my latest measurement is 908 at the headstock end and 920 at the tail end, so quite a lot better but nothing like close enough. I am starting to think this is nonsense, because I seem to be adding twist to try to reduce taper. In addition the finish is bad at the far end of the bar, which is what one would expect I believe, and probably enough to account for the taper.

basically it doesn’t seem to be working. I’m worried too I could damage the lathe.

arghhhh!

Steve

I will give that a go once I’ve finished the current thing, thanks.

Ok, you are right, it’s all me. I did that and it’s very close to parallel - about 1 thou out. I checked again with the micrometer and got the about .5 thou. Luckily this is the “beginners” forum so I am allowed to be an idiot.

Why did it give me an incorrect reading on the other side then?

Ok, just had a close look at it, it isn’t a Starrett but a Rabone. That makes more sense,

here is a 0.004 feeler gauge under one end. I would imagine that makes it sensitive enough to be useful?

i measured it with the micrometer and got exactly the same result, but it’s easier to show on a picture with the dial gauge. But I will try what you suggest,thanks.

According to Harold’s website I should measure along and across the ways. Across the ways gave an imperceptible difference, there is a tiny difference along the ways so those are the pics I took. I’m used to winding sticks on wood so across is where I went naturally, I was surprised about the longitudinal measurement too.

Obviously it’s an eBay special, but I had to try to find a small one as the lathe is only tiny, I don’t have much info on it other than it’s a Starrett. I will check it with the smallest feeler gauge I can find and see what it does.

Another newbie thread - sorry!

I am trying to turn a 2” long brass  cylinder to 0.5” diameter, at the same time I’ve been trying to follow Harold’s lathe adjustment instructions on his website.

I am finding I am getting an unwanted taper of about 0.008 across 2”.

1) I have used a level to check the ways for twist and it seems minimal.

2) The gibs all seem tight

3) I added tail support (I was getting 0.015 before I did that). I realigned the tailstock when I did that.

can anyone please suggest the most likely thing to check or recheck?

A few pics below.

thanks

Steve

Edited By Steve355 on 02/10/2021 20:09:35

That’s interesting. I have a 4 way tool post, which accepts 1/2 inch bits, but I don’t think it is original. I had been shimming up 8mm bits before I started grinding my own. Perhaps I will invest in some smaller blanks. As you say, it is tedious to grind the 10mm HSS.

after having watched a few more videos I can see that tool rests etc are not actually required, just a steady hand. But given I already have one, seems to make sense to use it, particularly in the early days as I try to figure out what I’m doing. Actually I’m thinking now that my cheap grinding wheel, which is fine for chisels, isn’t really up to the task of HSS tool bits.

I’ve watched her videos so much I am beginning to feel guilty! She’s great, but didn’t quite answer my question on this one.

Excellent video, thanks. I get it now. The honing doesn’t need to flatten the entire surface like one tends to (but again doesn’t need to) with woodworking tools. I loved the honing machine at the end.

Cos the two blanks I bought are 20cm long and I was expecting to make 4 tool bits out of them!

Not something I will do again.

Steve

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

Right, I am getting there at last…..

I lashed up a belt tensioning system so could tighten the bearings to stop the chatter without the belt slipping….

I ground a radius on the tool bit….

and the result was a much, much better finish, and no chatter marks further out along the piece.

now to watch some more videos on grinding tool bits properly.

Thanks very much to everyone who has provided such great advice, all of it has made me think. I’m beginning to think I will be able to use these tools in the end.

Edited By Steve355 on 29/09/2021 21:22:37

Right, thanks for all the help from this excellent forum, I think I’m starting to understand some of this. I think there are actually three problems:

1) a problem With the collar at the tail end of the spindle, looseness was causing longitudinal movement of the spindle. I think I have fixed that.

2) A problem with tooling, resulting in the finish being a “long thread” when tail support is applied. The tail support would also stop any longitudinal movement of the spindle. I will re-grind the tool tonight and give this another go.

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