ALG 100 nasty vertical head rattle

Dear all please help on this.

I started making some T nuts on my ALG100 FP1 copy.
Straightforward job, started by side facing the 20mm (3/4") part. 1060 steel, nothing too hard.



Problem is that even at modest cuts, a couple of tenths of a millimeter I had a huge knocking/rattle sound from the vertical head.
I think it is very obvious in this video

vertical head rattle - YouTube

I, instantly took the front of the vertical head apart and examined the bevel gears, nothing seemed problematic. Tried again, same thing. If I tried higher speed and even lighter cut knocking reduced but the surface finish was just awful, a constant chatter (forgot to take a picture...).

Trying to identify the source of the rattle, I noticed that the keys had some play in the spindle's keyway. (that instantly reminded me of a similar post I had read here)
Play is as such:

key rattle 1 - YouTube

Took the vertical head apart and found out that the keys had some wear towards the spindle. Keyway seems relatively consistent in terms of width. Please have a look here:

key rattle 2 - YouTube

So, has anybody faced such horrible sounds? Do you have any suggestions on the possible root cause? Could it really be attributed to the key wear? I mean, there is a couple of gears in the drive train, I can't see why just a bit of play in the key would cause such an issue.

Would really appreciate any help on this.

BR,
Thanos

So what are you using for a tool? Got a picture, close up?
Cutter diameter,Length of cut? Speed and feed?

Which direction are you cutting....Climb milling perhaps?

I would start by getting the tool closer to the spindle....Too much overhang there....Not familiar with that machine...what kind of spindle bearings does it have..."anti friction" or bushing....

Have you run this machine for similar work with no noise....

Cheers Ross

Hi Thanos, could you simply make up some wider keys? They might have to be wider on one side than the other if the slots are not the same size. Cheers, Bruce

Hi guys,

@ Ross: tried two 14mm and one 12 mm 4 flute end mills, with same exact results, that is: same rattle... Tried speeds from around 250 to 1000 rpm. Slow feeds mostly (can't recall exactly), conventional milling. Length of cut (height for the particular case) 22 mm. Depth of cut less than 0.5 mm.
Can't remember having taken such a 'deep' cut on steel before (machine is new to me) but have cut so deep grooves in aluminum with even longer end mills and don't recall to have been bothered by something.
Sadly tool overhang is not easy to overcome, original collets are a bit worn so I reverted to ER32 in the MT4 spindle.
Spindle bushings are of the 'older type', i.e. tapered bronze. Bevel gear bearing seems fine, but have to check again.

@ Bruce: That's what I think I'll do, though I wanted the forum's opinion first if it is an actually possible cause.

Thanks guys

Pretty sure you can buy new MT4 collets for this machine at reasonable cost (under 30 Euros as I recall) from RC Machines.

ballen said:

Pretty sure you can buy new MT4 collets for this machine at reasonable cost (under 30 Euros as I recall) from RC Machines.

Click to expand...

Well, ER systems was chosen also for use as drill chuck, since the mill is vertically challenged with that tall swivel table and the albrecht chuck won't leave room for much...

I can also get a couple of these Zugspannzange, 355E Deckel S2x2 FP, rund, d = | eBay and leave the ER for the non-demanding operations.

However, after all that trouble yesterday I tried the horizontal head with the same ER32 collet chuck. Had no issues, nice and smooth cutting.

thanvg said:

I can also get a couple of these Zugspannzange, 355E Deckel S2x2 FP, rund, d = | eBay

Click to expand...

Yes, that's what I meant. These collets from AllesGute are a good deal, I have a couple of them for inch-sized tooling and they work well. You might want to get a handful of them to reduce the amount of vertical space that you lose to the ER collet chuck.

ballen said:

Yes, that's what I meant. These collets from AllesGute are a good deal, I have a couple of them for inch-sized tooling and they work well. You might want to get a handful of them to reduce the amount of vertical space that you lose to the ER collet chuck.

Click to expand...

Yes Bruce, I'll get a couple of standard sizes for space-tight tasks. Nice to have options, though it's nice to have uniformity as well.

Anyhow, all these don't really matter unless I find out what the problem with my vertical head is. Hope I clear this out, it's not a very complicated mechanism...

@ Ballen

What´s your experience with those mentioned collets and that supplier? They look a bit nice but reading the stated run-out of 0,03mm, that´s basically on par with my drill chuck? Have you checked yours if that´s what they are?
Anyway, I guess it is stated because that´s what they might be a bad day maybe..

@OP, sorry for the slight hi-jacking of your thread...

As a test..Try less height (Z) of cut (.8 x cutter radius)
More depth..
RPM somewhere around 500-800
Feed fast enough to keep things loaded...
Cheers Ross

You might also want to consider one that goes directly into morse taper 4, rather than using the 355E adaptor. I mean ones like this (also available via the German ebay site)

Morse Taper Collet MT4 (MS4) with S2x2 saw thread 54E #994 d= | eBay

Lumberjack said:

What´s your experience with those mentioned collets and that supplier? They look a bit nice but reading the stated run-out of 0,03mm, that´s basically on par with my drill chuck?

Click to expand...

The run-out was not enough for me to notice, but I'll measure it and let you know. I need to put it into the adaptor holder then into the SK40 taper, so if there is significant run-out, it might also be the adaptor holder.

Cheers,
Bruce

AlfaGTA said:

As a test..Try less height (Z) of cut (.8 x cutter radius)
More depth..
RPM somewhere around 500-800
Feed fast enough to keep things loaded...
Cheers Ross

Click to expand...

Ok Ross, this sounds like a nice thing to try. I mean, the 'fast enough to keep things loaded' makes sense to me, since the whole thing gets motion through gears, so there is slope by design everywhere!

Thing is that I already took it apart and started making some tighter fitting keys (keys are almost 0.5 mm worn, keyway seems nice). So, in case is works better, won't know if it's your advice, or the new keys...

Also, if I may...if you absolutely need to mill the side of a part (for various reasons, we assume that we absolutely have to mill the side), and let's say this side is, e.g. 50 mm tall (2" in height) and there is no room to fit a 50/0.8=62.5 mm mill diameter, how would you do it. E.g. widen a bit a narrow and deep slot. It should be possible with a 900 kg mill, right?
(I assume that " (.8 x cutter radius)" is for the cutter diameter, right? If it refers to the cutter radius, things are even worse...)
Looking forward to your advice!

ballen said:

You might also want to consider one that goes directly into morse taper 4, rather than using the 355E adaptor. I mean ones like this (also available via the German ebay site)

Morse Taper Collet MT4 (MS4) with S2x2 saw thread 54E #994 d= | eBay

Click to expand...

Not bad alternative Bruce. I imagine using one clamping item (MT4 collet) instead of the adapter+deckel collet could, in principle, reduce runout. (provided, of course, that the MT 4 collet is well built). Also, it is the shortest option for deckel-type mills, so could be worth if a very tight job it to be undertaken.

But, they are a bit pricey at 55 GBP.....

Dear Thanos,

You can find them for less. As I had originally suggested, RC machines has them for 19 Euros here, in diameters from 4 to 25mm:

MK4
and I think the quality is decent.

AllesGute has them for 36 Euro:

Direktspannzange MK4 S2x2 Sagegewinde , 54E (G198) , d= | eBay

and Franz Singer has them for 49 Euro:

Direktspannzange MK4 S2x2 D6 gebr. z.B. fur Deckel Frasmaschine | eBay

You could also use generic MT4 collets with an M16 thread like these ones, which cost 15 Euros:

MK4-Direktspannzange 539E, O 3 - 25 mm, Anzugsgewinde M16-RCDSZM4

together with S20x2 adaptors like these ones, that cost 5.60 Euros:

Anzugsbolzen SK4 M16 mit S2x2 Sagengewinde (G172) | eBay

Cheers,
Bruce

Dear Thanos,

I realize we have gotten off-topic. Your test with the horizontal spindle shows that the problem with your vertical head lies elsewhere. Nevertheless it is sometimes useful to have rigid tool-holding, so I thought I would follow up on the Morse Taper 4 holders with S20x2 drawbar threads.

You can find them for less. As I had originally suggested, RC machines has them for 20 Euros here, in diameters from 4 to 25mm:

Spannzange MK4 O 4 - 25 mm mit Gewinde S2 x 2 mm-RCSZDMK4
and I think the quality is decent.

AllesGute has them for 36 Euro:

Direktspannzange MK4 S2x2 Sagegewinde , 54E (G198) , d= | eBay

and Franz Singer has them for 49 Euro:

Direktspannzange MK4 S2x2 D6 gebr. z.B. fur Deckel Frasmaschine | eBay

You might also be able to use generic MT4 collets with an M16 thread like these ones, which cost 15 Euros:

MK4-Direktspannzange 539E, O 3 - 25 mm, Anzugsgewinde M16-RCDSZM4

together with S20x2 adaptors like these ones, that cost 5.60 Euros:

Anzugsbolzen SK4 M16 mit S2x2 Sagengewinde (G172) | eBay

But I am not sure that the spacing/length here would be correct, so this last approach would only make sense if you already have some M16 collets on hand, or can get them locally at a very good price, and are prepared to go with "plan B" if there are issues with length/fit.

Cheers,
Bruce


PS: many people are not aware that these are available new at decent prices, and so used Deckel ones are often priced higher than I think they should be, for example here:
https://www.ebay-kleinanzeigen.de/s...e-f-zb-deckel-fraesmaschine/420891637-84-1328

ballen said:

Dear Thanos,

I realize we have gotten off-topic. Your test with the horizontal spindle shows that the problem with your vertical head lies elsewhere. Nevertheless it is sometimes useful to have rigid tool-holding, so I thought I would follow up on the Morse Taper 4 holders with S20x2 drawbar threads.

You can find them for less. As I had originally suggested, RC machines has them for 20 Euros here, in diameters from 4 to 25mm:

Spannzange MK4 O 4 - 25 mm mit Gewinde S2 x 2 mm-RCSZDMK4
and I think the quality is decent.

.......

Click to expand...

Thanks a lot Bruce! Apart from the extra rigidity, using direct MT4 collets instead of my ER32 configuration would save almost 40 mm in valuable headroom! (though, most of the times headroom is more of a problem when drilling than milling, but still...).

Regarding the original Deckel items, I guess that originality is, sometimes, too important to pass...

Now, to our (my...) actual problem: I managed to make one of the keys (well, almost, still have to make the round pin thing). Let's see how this will work...

ballen said:

Dear Thanos,

You can find them for less. As I had originally suggested, RC machines has them for 19 Euros here, in diameters from 4 to 25mm:

MK4
and I think the quality is decent.

...

Click to expand...

Well how about this?
German version: Deckel S2x2
English version: Deckel S2x2

That's why I didn't have them in mind....

Will let them know!

Hi guys,

well, I used the horizontal spindle to make some keys to replace the worn quill keys on my vertical head



Not the most good looking keys but they have perfect fit (punch mark was use to center the key on the lathe, since a flat rotary table is of no great use when trying to repair the vertical head and all you have is the horizontal spindle...Also, the offset button is because the hole for it was drilled a bit off with respect to the keyway at the factory. I don't suppose something like this could be found on a Deckel....)

Put everything together and repeated last week's exercise. Same material (1060 steel), same depth and width of cut, same tool, and ... got the same noise. I mean bad rattle/knocking, excessive chatter. Gave a very hard time on the cutter, all cutting faces got chipped. Decided to change the conditions and try some delicate plunge milling, chatter and noise again. Switching from the ER32 collets to the deckel system, same thing....

So, I started looking into the spindle bearings. By inserting a soft wooden mallet handle in the MT4 taper and pushing the spindle sideways I got up to 0.12 mm play. Not sure how hard I should push but I think I touched the bronze taper bearing at both sides. So, we have some play to calibrate out.
When I got the mill on November, some 20 hours of operation maximum, I had adjusted the side play, does not seem proper to require adjustment again.
Anyhow, I took the spindle apart and turned down the washer by 0.05 mm and put it back again.
Took a trial cut, things were hugely improved! Some chatter is still there, but cuts are now feasible.

Satisfaction for identifying the issue is there, but the fact that my spindle requires attention is not something I am very fond of. I fear that, due to wear in the spindle bearings, side-play adjustment is not proper. Spindle taper does not have full and proper contact (or, barely contact) to the bearing taper, so it wears out fast and requires adjustment. I was in a hurry and frustration to try the spindle yesterday, so I got no goods pics, here is a picture from when I first took the vertical spindle apart:



And, for comparison (though most of you know how a nice spindle is), the horizontal spindle:




Has anyone ever had a worn plain-bearing vertical spindle? Did it result in such chattering issues?
Did you keep adjusting it or did you have it fixed?