Member postings for Steve355

It’s an optical illusion! The top faces of the two pulleys are the same size. The hole on the right pulley is just under 1/2”. The hole on the left pulley is 3/4”. The motor shaft diameter is 3/4”.

Steve

Edited By Steve355 on 28/10/2021 23:22:39

Hi again

One other job I have to do to get my mill going properly is sort out the pulley on the motor. The motor that came with the mill blew up (literally), but luckily an extremely kind chap on the Dore Westbury group gave me a spare motor he didn’t need any more.

Trouble is, it has a larger diameter spindle than the original motor I had, and so the original pulley doesn’t fit, which means I can only use one speed. So what to do….

1) bore out the original pulley to fit the motor spindle

2) Turn a new one on the lathe - which would be good lathe practice for me, but I’d be concerned about messing it up.

Thoughts?

Steve

Yes, good idea, I will check it very carefully. I had another play with the table on the mill this evening and it seems like it will indeed run true, which is a good result. I think I’ll have a good look at the Y axis mechanism too to see if I can identify any further faults while it’s all apart. I’m sure there are more problems to find.

John, do you mean this bit?

Hi Howard

If I’m understanding you correctly, I am in the lucky position of not needing to, I think.

First, I have the drawings for the Dore Westbury mill, so I can look up exactly where the holes need to go.

Second, because the ****** person who built the mill installed the table the wrong way round, there are NO HOLES in the end (see pic) that actually should have had the lead screw/handwheel attached. So I can drill completely new ones, in exactly the right places.

And I feel vindicated now because when I came home to face my wife last summer with a 6ft tall Jones and Shipman pillar drill I got for £10 on eBay, she said a drill that big would never be any use. How wrong she was.

Thanks John, it’s really helpful to know I’m not just going mad. I’m very new to all of this and it’s particularly difficult with a machine that wasn’t professionally built in the first place, to know what’s right and what isn’t.

I just turned the table around and threw an indicator on it, moving it manually. Even without the gibs or hand wheel installed, I can see that it is way better than before.

I also may have found the source of the “wobble” and hand wheel stiffness. If you look at the pic above of the table the wrong way around, you can see that the screw holes that attach the handwheel tray are poorly placed. This would place stress on the lead screw - causing the same effect as it being bent, I would expect. So I can sort that out too.

Now I’ve just got to work out how to drill accurate holes in the end of that table. Luckily I have a big pillar drill!

Cheers

Steve

What I’m hoping Howard (optimistically) is that if I turn around the table and everything is suddenly aligned the way it should be, I could take a test cut and check if it’s square. If it is, I just need to drill a couple of holes in the end of the table to fit the hand wheel. If not, I have a bigger problem! And will be looking at the kind of things you suggest above.

Steve

Right, I spent some time on this before work today.

This all started on Sunday night, when I wanted to start to make some vise jaws (missing from vise I bought on eBay). I decided to mill a test piece to check for square before I started squaring the ends of the stock for the jaws. It wasn’t square.

I think to some extent I am chasing ghosts. I’ve been measuring with reference to the base. I’m not sure this is relevant.

Is this statement true? :- It doesn’t matter if the milling table is not square to the base of the mill (within reason). The milling cutter is round. What matters is that the X, Y and Z axes run perpendicular. Tramming ensures the Z axis is perpendicular. The X and Y axis should be perpendicular by manufacture of the table.

Looking closely at the Dore Westbury table, one of the slideways is precision located with dowel pins on a ground surface. It looks to me that this is supposed to be a perpendicular reference surface. The other slideway isn’t so important.

TABLE

BASE

Looking at the base it sits on below, there is a perpendicular ground surface. That looks like it should mate with the precision perpendicular surfaces on the table. This would guarantee that the table and the base run parallel.

However, they don’t. See below how it is…. The non-precision located slideway is against the ground guide.

And clearly, this is how it should be….

So basically, it looks like the table was installed the wrong way round. In fairness to the bloke who built it, he does seem to have followed the drawing.

This would explain why the table is wonky, and why I’m not getting square parts.

I’d appreciate any views on this. Am I right?

Cheers

Steve

Thanks for the ideas chaps, I will take a closer look in the morning.

You are absolutely right, the gib strip (located under the display of the calliper) pushes the table against the guide rail, which is located under the right arm of the calliper in the pic. I need to look into this more.

I know it must seem like I’m always asking questions on here, but I’ve solved loads of other problems on my own, honest!

While trying to work out why my mill table was wobbling (which I think is fixed now) I noticed that the vise didn’t seem square, so I put an indicator on the mill table. Lo and behold, it didn’t seem square to the base - about .015 movement across about 2/3 of the width.

So I took it to bits again, and it turns out the the ways are not parallel. 3.0” at one and and 2.973 at the other. In fact, you can actually see this difference from the outside. I’ve put this all in pics below. Only thing is, I’m not 100% sure that the indicator movement is in the same direction as the slideway parallel difference, it something is definitely wrong.

I guess, Dore Westburys being originally a user built kit, it was an error in the original build.

Before I start messing around trying to re-bore the countersunk screw holes in the slideway to put them in the right place, I would ask here for opinions on what to do (if anything). And ideas on how to do it, that doesn’t involve using a milling machine, cos it is in bits again.

Thanks

Steve

Edited By Steve355 on 26/10/2021 21:32:32

Edited By Steve355 on 26/10/2021 21:34:26

That’s right, and also they have an aluminium tray at the end which is nothing like as solid as the cast iron. This provides a very long lever arm to wobble the table laterally.

Thanks Pete

I’ve examined the lead screw and it isn’t obviously bent, but I will take another look.

there is a stiffness in the handle that always occurs in the same place in the turn. I think that whoever is causing it, is related to that,

cheers

Steve

Actually the table wheels are spoked. I might give that a go.

I did have the best genius idea of putting some oil on it earlier and it seems to turn a lot more easily.

I am beginning to want to add a power feed already.

Yes indeed, but in this case it looks like they can sit in the dimples in two ways.

If the gibs sit on the bed, the gib screws will push the upper side of the dimple, and only the top inner corner of the gib will make contact with the slideway. Looks like that’s why the gibs weren’t locking the table.

if the gibs sit about 1mm above the bed, the screw fully engages in the dimple and the entire gib contacts the slideway, providing a lot more friction. I’ve now got it like this and the gibs can lock the table properly. I can also not move the table at all in the hoizontal plane.

But there is also a vertical component. I think I was turning the handle too roughly, which seems to flex the table - only very slightly, obviously. But it doesn’t take much to create a .002” movement on the DTI. The gauge plate I was using was very slightly off square to the table, so a slight vertical movement moved the DTI needle.

I think I’m getting there.

Steve

Looking at the drawing, perhaps the gib is supposed to be “raised”, when I’ve installed it it just slots in and settles on the bed. It feels right, but according to the drawing it isn’t. I will have a go at that next.

No, it doesn’t seem to, and I can get them all as tight as they will reasonably go and the table will still move. Getting stiff, but it moves. I’m thinking perhaps the gibs are installed incorrectly.

done it now, same result, now 0.002 wobble on DTI. 😢

John, you may just be a genius… certainly another line of investigation….

I have it apart again, the strips are all tight and seemingly in good nick. I am wondering about those spring dowels. I can’t seem to post pics of the drawings here, but I can’t find anything about them on the drawings except the holes in which they go.

see pic below, do you think that looks right? I can’t see the point of those holes myself, so Is something missing perhaps?

>>What's holding that bit of bar you have the clock running against? looks like it's just stood on top of the fixed jaw.

nothing, it was just an experiment to check it wasn’t imperfections in the surface of the cast iron on the vise. Same results.

>>you are talking of wobble or just the steady change in reading from one point to another.

wobble, it is “wobbling around a steady change” if you see what I mean

as Michael also suggested I will take the vise off and eliminate that as a variable.

Thanks!