Emco FB2 (Taiwanese clone) radial spindle play

I'd really appreciate help from those who know and use the EMCO FB2 milling machine.

I've had an Axminster clone for about a year now, and it seems to do impressive work for it's size. However, I have difficulty tramming or centring, because of radial play in the spindle.

Putting an indicator at the spindle, as close to the head as I can, gives me play of 0.04mm if I press in either direction with my thumb.

The top of the spindle (where you insert an allen key for collets etc) has a play of around 0.07mm. I guess that's to be expected given the top bearing arrangement.

I'm wondering whether the play is due to wear, or whether it was always like that - the mill is in excellent overall condition and doesn't seem to have had much use. There's very little play in the slides. Maybe the Taiwanese factory didn't take quite the same care that Emco did when selecting/matching the needle roller bearing to the spindle?

So my questions are:

1. Is 0.04mm excessive?
2. Should I attempt to do anything about it?
3. If so, what are my options?

Thanks in advance, Paul

0.04 mm is quit a lot.

If you want to measure the spindle play, you have to avoid measuring the flex/bending in the mill. You should place the (magnetic) base of the indicator on the housing of the spindle, not on the milling bed.

You want to measure the play in the spindle so lock the quill to avoid measuring the play in the quill.

Measure the play in all directions

Most mills (and lathes) have contact angle/tapered bearings and those bearings can be adjusted to reduce/remove the play.

Have a look at this thread Emco FB2 bearing replacement

Keeping the indicator still and rotating the spindle for each measurement, the total radial play varies between 0.03mm and 0.04mm, implying a slightly oval spindle. But it's never less than 0.03mm. (Yes, the indicator base was mounted on the head, with the quill locked)

I also have an older 'Mentor' mill head on my lathe. Its radial play is barely measurable: < 0.01mm.

So I'm now thinking the play in the FB2 clone needs addressing. Unfortunately, it doesn't use tapered bearings - just a needle roller cage acting on the spindle itself at the bottom.

The parts are no longer available, so I see the following options:

1. Find a used spindle
2. Lap the spindle and make a bronze bearing, as suggested by Ray Griffin in the thread you linked to.
3. Try and find oversized needles?

I'd be grateful for any other options. In the meantime, I'm going to see if I can adapt the mentor to fit the FB2 mill - not straightforward as the column diameters are different.

Paul

Before you go stripping it down.

Where is the clock mounted?

Is it actually attached to the Milling Head or on the Table?

If it is mounted on the Table then the thumb pressure is also moving the Head on the Column.

If the Clock or Indicator is mounted on the Milling Head then provided the Quill is locked. Any play recorded is actually in the bearings.

Also keep in mind that these Needle Roller bearings have a little play in them, 0.005 to 0.01 mm. This will disappear as the bearing becomes dynamic, ie when the spindle is rotating and running on a film of oil.

This bearing fills with oil over time and becomes in essence an Hydraulic pump and the oil is in-compressible.

I have used FB2's for over 40 years, the spindle was never an issue once you get to know the machine.

Regards

Gray,

Your post came in while I was typing,

Edited By Graham Meek on 08/07/2023 11:01:15

An equivalent bearing made in Japan has one extra roller from the standard one fitted. I obtained one from Simply Bearings, (usual caveat).

Regards

Gray,

Thanks Graham,

I didn't want to make my initial post too long by detailing my measuring technique - sorry my next post overlapped!

I have an update which gives me a little more hope.

Keeping the indicator at the bottom end of the spindle (mounted on the head, quill locked). I tried pressing the top end of the spindle radially. Keeping light pressure on the top end, I then pressed the bottom end as before, and the indicator barely moved.

This makes me wonder if the top bearings are causing the issue somehow?

Paul

I have a Mentor mill and I modified the quill to take a pair of taper roller bearings and a new spindle I made. I then bought a 6 speed head with column and bracket (to fit rear of V10 lathe) with the intention of fitting it to the Mentor. I had several attempts over three years but could not find a way of marrying the two together.

It might be easier to fit the smaller column and head on your FB2 than what I was trying to do, but you will have less rigidity and less power.

Currently I'm going to have to strip down my 4 speed head as one of the Tufnol gears has shed its teeth so only really have one speed, the VFD make it usable but I am now looking at converting to belt drive.

As an aside, do all FB2 'clones' have the same spindle bearing arrangement? I just thought FB2 clone just meant a mill with the same general design, round column, tilting geared head etc.

Ian P

This is a good question. As far as I know, they're almost identical (See the lathes.co.uk page), and one might reasonably assume that Emco had some involvement in the clones once they started to produce the FB2s in Taiwan. Indeed, underneath the Axminster White, my mill is painted red - gloss, not primer.

But there are differences. For example the spindle is extended on my Axminster clone, with a thread to take Myford collets. Really annoying as they're too expensive to be of any use, and just has the effect of making the cut an inch or so further from the bearing than it otherwise would be.

More pertinently, they seem to use the same general bearing arrangement, but I don't know whether they use the same custom bearings that Emco used. For example, are the upper thrust bearings the same custom deep-grooved bearings, or just two angular contact bearings?

According to lathes.co.uk, the Taiwanese clones are very well made, and perform well, but I suspect they didn't go to the efforts that Emco did in matching the bearings to the spindle. I think this could be a factor in the play I'm getting.

Paul

Edited By Diy Addict on 08/07/2023 12:29:03

The two bearings at the top are sort of standard ball races and could possibly be at fault. Have you checked to see if there is any end float on the spindle? If there is some play, then I would say this is where the fault is.

These bearings are retained by a Ring Nut on the FB2 which has a Left hand thread on the spindle. You will need a peg spanner.

I had replaced the bearings on one machine with Angular Contact Bearings, (back to back). These are a direct fit. The original Emco bearings were a matched pair of standard bearings which are specially selected by FAG. These have minimal clearance when loaded correctly. These bearings had two markings on and these markings had to be assembled with the two marked faces together.

Perhaps someone has had this machine apart and not re-installed the bearings correctly.

If you are taking the spindle apart then I would get two angular contacts in ready.

Regards

Gray,

Just checked, and there's no end float. I'm pretty sure no-one's had it apart before (As a former service engineer, you tend to spot the signs!). So still a mystery at this stage.

But I've found a used FB2 spindle on Ebay US, and bought it! The supplier won't post to the UK so it's going to take a convoluted route involving relatives.

Assuming it's not knackered, I'm hoping it'll fit straight into my clone, so we'll soon see how similar they are to the real thing.

If that all works (gulp), I'll be able to make further investigations into my spindle on the bench.

Edited By Diy Addict on 08/07/2023 16:58:34

Good luck with the replacement Quill assembly.

Regards

Gray,

Thanks Graham, I really appreciate your help. Will report back here once it arrives.

Paul