Emco FB2 (Taiwanese clone) radial spindle play

[Diy AddictParticipant @diyaddict]

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

[Diy AddictParticipant @diyaddict]

[HuubParticipant @huub]

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

[Diy AddictParticipant @diyaddict]

Posted by Huub on 08/07/2023 00:02:22:

0.04 mm is quit a lot.

Measure the play in all directions

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

[Graham MeekParticipant @grahammeek88282]

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

[Graham MeekParticipant @grahammeek88282]

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,

[Diy AddictParticipant @diyaddict]

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

[Ian PParticipant @ianp]

Posted by Diy Addict on 08/07/2023 10:58:35:

Posted by Huub on 08/07/2023 00:02:22:

0.04 mm is quit a lot.

Measure the play in all directions

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

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

[Diy AddictParticipant @diyaddict]

Posted by Ian P on 08/07/2023 12:12:08:

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

[Graham MeekParticipant @grahammeek88282]

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,

[Diy AddictParticipant @diyaddict]

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

[Graham MeekParticipant @grahammeek88282]

Good luck with the replacement Quill assembly.

Regards

Gray,

[Diy AddictParticipant @diyaddict]

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

Paul

[Diy AddictParticipant @diyaddict]

Well, it took a few months to wind its way from the USA to the beautiful Forest of Dean UK, but I now have my spindle, and it’s been in use for a while now.

The original clone quill assembly (with the Myford collet nose) is on the left, and the well-travelled Emco assembly is on the right. There are a few differences, notably the large bearing at the top. My clone’s head casting doesn’t have enough depth to accommodate the Emco bearing, but it’s an easy fix: Just unclip the circlip and the large bearing and gear slides out, then just swap them – they interchange perfectly. A very minor modification was also made to the oil seal position on the clone’s head, but that’s a subject that would be better detailed in the ‘Emco FB2: Quirks and Additions’ thread, if anyone’s interested.

Anyway, the difference is night and day. The spindle play is now barely measurable, and this shows in the ease of making cuts and the surface finish. I feel I could quite easily make twice the depth of cut that I could before, and finally, I can centre-find using a DTI. I’m really enjoying using my FB2 clone now, and I was very lucky the quill assembly turned up at the right time.

I’m also in a position to investigate the problem with the original spindle at my leisure, but that’s now much lower on the priority list. If anyone’s interested in the original fault, please reply here and I’ll make an effort to strip it and diagnose properly.

All the best, Paul

 

 

[Graham MeekParticipant @grahammeek88282]

Hi Paul,

Glad to see you are sorted out, where abouts in the beautiful Forest of Dean are you? Anywhere near Cinderford?

Regards

Gray,

[Diy AddictParticipant @diyaddict]

Hi Gray. Near enough – I’m in Lydney. Moved here over 20 years ago and loved it ever since. Would love to meet up sometime. I’ll PM You.

Paul

[snewellParticipant @snewell]

Hello,

I have a Warco copy of the FB2 and was looking for advice on spindle end play, this thread and forum has been most helpful so far. There is about 5thou of movement at the spindle end in all directions so decided to take the mill apart. I’ve haven’t had it that long and I purchased it from an ex model engineer.

Now the quill is out the top two ball races are damaged, you can feel this when they spin. I was surprised they are just normal NTN ball races as I didn’t think these are really designed to take axial loads. Can anyone advise on the following questions I that might help me with my next steps:

1. Is that the same top bearing arrangement on the original EMCO FB2, which are better quality models? Someone has clearly had a go at the locking collars to the top bearings so I am wondering if the bearings I have removed might not be the machines original ones?

2. As the bearings are 47OD x 25ID x 12mm Would I be better off purchasing some back to back angular contact bearings?

3. Is it worth replacing the bottom roller bearing too (the spindle looks in good condition with no damage or wear). If so what bearing tolerance is needed – has anyone ever done this with their EMCO or copy mill?

Thanks for reading!

Steve.

[Graham MeekParticipant @grahammeek88282]

Hi Steve,

I tried to post this yesterday but the Forum was having an away day.

In the Emco Quill the two top bearings while they may look like standard bearings, they are anything but.

 

These bearings were specially prepared by the bearing manufacturer. When the two are clamped up onto the spindle they have almost Zero sideways movement. These bearings are not available commercially.

All standard bearing can tolerate Axial Thrust, or Loading and this is usually about half the Radial Loading. To eliminate any axial play, standard bearings would need a shim between the bearings. This would need to be carefully gauged as it this is over done then too much loading would cause the bearings to fail prematurely.

Angular Contacts would be a good substitute used in “Back to Back” format.

The original Emco Needle roller bearing was specially selected to match the Spindle diameter. This diameter had 3 basic sizes, 30.023, 30.028 and 30.033 mm. These bearings are also no longer available. I did manage to track one down about 14-15 years ago and it cost £60.00.

I did however rebuild a friends Quill about 5 years ago. The Needle roller bearing used was obtained from “Simply Bearings”, (usual disclaimer). This was made in Japan and had an extra roller when compared to the original Emco bearing. Standard bearings off the internet will have too much clearance.

The Spindle needs to be a good fit in this bearing. The sort of fit that requires the oscillation of the Spindle to align the bearing rollers. Then a good firm push by hand to insert the Spindle. Anything less than this will cause premature wear on the Spindle as the rollers will Skid rather than Roll.

Hope these notes help.

Regards

Gray,

 

[Ian PParticipant @ianp]

Gray, not sure if my memory is playing tricks but I seem to recall that a few years ago you described making from scratch, a new improved quill and spindle for an FB2 which I think did not use the Emco needle race bearing.

Is that the case?

Ian P

 

 

[Graham MeekParticipant @grahammeek88282]

Hi Ian,

Your memory has not failed you. However while the bearing arrangement was simpler there was no real gain in performance, over the original Emco design. I would say they got it right first time.

 

 

I had better just add that this Quill was a complete remake, and does not use any of the original parts of the Quill.

 

The Quill needed to be made 8 mm longer in order for the Taper Roller bearing to miss the Keyway.

The Spindle also being longer needs another longer Cap screw for the draw bar.

All of the parts were made on the Emco equipment I had at that time. The whole exercise was a valuable learning curve.

The original is now in the Southern Hemisphere. I had no longer use for it and a Forum member had purchased a mill without the Quill assembly. I have not had any feed back so I cannot give any more details.

Regards

Gray,

[Ian PParticipant @ianp]

As usual really nice work.

You say it had no real gain in performance but I would say that it does have one big benefit as your design is future proof. Needle bearings for FB2 and Mentor mill spindles are extremely rare in 2024 and if there are any new one around now there will be even less in 10 years time. Also any damage to the spindle itself may render the whole machine beyond economic repair.

I’m not sure Emco did get this part right.

Ian P

[Graham MeekParticipant @grahammeek88282]

Hi Ian,

While my design overcomes the bearing issue. Setting the preload on this bearing arrangement was a very critical affair. Too much preload and the machine, (single phase), would not start in High Gear. I set my design using a cord wound around the Quill and a Spring Balance. This setting was matched to the original Emco Quill reading.

The ideal set-up would have been two Taper or Angular Contact bearings “Back to Back” at the Spindle nose. That way any expansion in the Spindle would not affect the bearing preload.

From a manufacturers point of view the original Emco set-up did not suffer from this problem. Thus it was easier to assemble, even though there was some “Selective Assembly” involved as regards the Spindle Fits.

I have always found the wear problems with these machines to be associated with a poor maintenance regime. Emco call for the oil to be changed regularly in the Head. My last machine was filled with Castrol Syntrax on the advice of Castrol Technical department. This being a synthetic Oil does not need changing, (good for the planet), just merely topping up.

Regards

Gray,

[Ian PParticipant @ianp]

Gray

Setting preload is a bit trial and error with the relatively coarse threaded locknut, but it is a once-only procedure so I think acceptable on a small machine.

Regarding preload changes due to temperature, workshop good practice often suggests running the machine before use to thermally stabilise everything, its definitely not ecologically friendly although better than having to make a part twice!

When I bought my Emco Mentor the seller explained that it would not start in the highest speed (although he failed to to mention the bent spindle!) I think the reason is that Emco used a true 3 phase motor run in Steinmetz mode which results in some loss of power. More or less the first modification I made was to fit a VFD and since then have rarely needed to change gear ratio. As it happens it is stuck in one speed now because of a damaged Tufnol gear.

Ian P

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