How to stay in control of mill depth of cut? (My mill has no fine quill feed)

[AndyfParticipant @andyf]

I am not familiar with the Sieg HM-10, but it looks like one of the machines which Grizzly Tools sell in the US. They have an online manual for their machine, written in in American English, rather than Chinese English. I don't know if this might help you.

Andy

[Sub MandrelParticipant @submandrel]

The Clarke manual HERE is up to scratch too, possibly better advice on actual milling – they are obviously upgrading their manuals.

The Grizzly one has scared me off using my mill now:

Neil

Edited By Stub Mandrel on 17/03/2013 12:24:59

[John Stevenson 1Participant @johnstevenson1]

What about something like this that is sold for the X3 mill ?

http://www.arceurotrade.co.uk/Catalogue/Machine-Spares/X3-Small-Mill-Spares

Top item, carries a stanadr 4" vertical DRO bar.

[JC Uknz 1Participant @jcuknz1]

Thankyou all, Thankyou Andy that is a good link and a more informative manual than what arrived with the mill with its hillarious use of english There are small differences but my HM-10 looks very much like that in the manual. by Grizzly Thanks.

[Robert van der DriftParticipant @robertvanderdrift16271]

To all.

Concerning stick-slip of the slide on the main column:

As is mostly usual in hobby machines, the adjustment gibs are provided with small dimples and rounded adjustment screws in the saddle. Upon moving the saddle up and down, you can easily feel a bit of up and down movement of the gib itself. Consequently, with the gib riding on the rounded screws, the gib tends to bind and this causes the stick-slip effect. Also it is almost impossible to adjust the gibs as we would like to.

I solved the problem by drilling a 3 mm hole at a right angle in the left hand side of the FB-2 slider and straight through, into the full depth of the gib and fitting a round silversteel 3 mm dowel into the saddle and gib. I left the dowel about 4 mm sticking out so I am always able to pull it out using a vice grips. Being a bit lazy, I didn't want to dismantle the mill, so I did the drilling by hand. I checked the drilling depth and distance of the center of gib from the left back corner of the slide. In my case the drilling depth turned out to be 18 mm so check this frequently whilst drilling. After punch marking the saddle, I used drilling steps of 2,5 / 2,9 and finally 3,0 mm. Of course the pro's would take a 3 mm reamer at the end and use that, but the end result in my case was highly satisfactory and most remarkable. No more sticking and I could adjust the slide much better with less play.

Robert

[Sub MandrelParticipant @submandrel]

The great George Thomas was an advocate of pegging gib strips.

Neil

[Ian PParticipant @ianp]

Robert

I too have experienced the moving gib strip problem and carried out a similar modification to yours on my lathe cross slide which made a considerable improvement.

I will now check the Z gib (same as yours) on my mill.

It totally defeats me why some people refuse to drill a hole in a machine casting on the grounds that it is then non-original, each to his own I suppose.

Ian

[Ian PParticipant @ianp]

Gray

In the absense of a suitable strip of cast iron would brass be as good, worse or better?

Ian

[Robert van der DriftParticipant @robertvanderdrift16271]

Thanks Graham and Ian,

Graham, your point about the dowels' insertion direction from the back side in stead of from the side is a very good one. I didn't think about that. Also your point about the c.i. gib. Thanks. I'll start a hunt here in the Netherlands for a suitable piece of c.i. and then change "for the better". And yes, parallel to the adjustment screws. My mill is a clone and not an original one. I was stupefied by the spindle bearings. Read the thread about it. Your mill must be ok by now. I honestly admire your work. I partly solved the problem with the single ball bearing top bearing by adding an extra simple ball bearing on top of the original one and adding a few shims between the two outer rings so these bearing are now under some tension. I know, those two bearings are not angular contact bearings but I couldn't find suitable ones as the diameter of the quill is only 52 mm and I could only fit 48 mm dia. Guess I have to change these bearings in one or two years then.

Ian, I do hope you read Grahams remarks. A mill is no Swiss cheese with lots of holes. Nor Dutch cheese for that matter. So position your dowel hole at the back side of the saddle.

Robert

[Robert van der DriftParticipant @robertvanderdrift16271]

Hello Graham,

Thanks for answering! Concerning the clone Emco FB-2 needle roller bearing: I could order this at SKF. Bearing # : NK 30/20 TN . I payed € 24,95 ex VAT for this bearing. The top bearings, as I have them now installed are 6005/ C2 and 16005 normal. C2 stands for extra tight fitting bearing. I have the 6005/C2 at the bottom and the 16005 at the top with a brass 0,004 shim between the outer races. I couldn't use two 12 mm wide bearings that's why I had to use the 16005 which is 8 mm wide. As far as I can measure, there is about half a thou radial slack in the needle roller bearing which I think is ok for the time being. I even tried to get oversize needles but could not get them. I use SAE 140 hypoid oil, mainly to silence the gearbox noise. Also I found out, that I had to adjust the gear shift forks inside the gearbox in order to get a quieter running gearbox. It is allright now. Of course I stripped the hub/gear joint of the top tufnol gear. That was a long time ago. It was just pressed in on the lightly nurled hub. I fixed it by degreasing the hub and the gear itself and gluing it back together with epoxy glue. Cured it inside the domestic oven at about 80° centigrade for half an hour. No more trouble.

I will heed your good advice concerning the slide gib. Now the gib in the slide (thank you!) is way too flimsy. The locating slots in the other gibs are much too wide on my mill. The gibs on the X and Y have about 1 mm slack in it. I think I will hand fit the slide gib in order to get maximum rigidity.

Robert

[Ian PParticipant @ianp]

Gray

Your knowledge of these machines is impressive. Nowadays many manufacturers (or their agents) give out their own part number freely but rarely give generic bearing numbers let alone tolerances.

Going back to the gib strips, I am tempted by your recommendation that CI versions make a big improvement. When you say fill the gib strip space, do you mean making them 1mm (or whatever the existing gap is) thicker?

From my POV making a new X axis strip would require access to another milling machine. ideally I presume they should be surface ground too?

Ian

[Ian PParticipant @ianp]

Gray

I can easily see how fitting new gibs to an X1 mill will make a significant improvement, in fact any improvement at all to an X1 is a big improvement!

I fitted ballraces on all the leadscrews and they made a truly dramatic change, I also relocated the Z axis leadscrew so its nut was clamped directly to the moving head rather than at the end of an 'L' shaped bracket out in mid air.

Going back to the Emco gibs, could you have eliminated the last stage of machining by mounting the slitting saw on the tilting head? also, where does one purchase cast iron in long strips?

Ian

[Ian PParticipant @ianp]

Gray

I had assumed that you did not use the FB2 to make its own X axis gib strip as its table travel is always going to be less than the gib length. My suggestion of 'tilting head' was misleading though.

Ian

[Ian PParticipant @ianp]

Doh!!!!!

My apologies Gray, I have even managed to confuse myself. For some silly reason I got it in my mind that the gib strip was on, and therefore as long as, the moving part of the slide. I have just measured my Mentor mill and the X gib is 300mm long and the table has almost 350mm travel.

I have not measure the gib section yet but it looks very similar to your drawing.

When I make new gibs I think I will put additional adjusting screws between the existing ones. My gut feeling is that more points of contact between the back of the gib and the supporting casting will increase the rigidity of the slide.

Ian

[Ian PParticipant @ianp]

Gray

I do not have a manual for my mill but I am now wondering whether my machine should have the push rods in the adjustment holes? Your mention of them, and the fact that the existing (M6 Allen grub) screws are quite long at 25mm make me think that it might be worth fitting them.

I presume the holes are tapped all the way through so the push rod would only be sitting on the thread crests but since no real movement takes place it should not pose a problem.

Ian

[AndyfParticipant @andyf]

I second Gray's comments about dowels into the gib strips. As to spherical ended screws, I had to go even further with a Chinese lathe gib where the dimples weren't quite in line. The gib twisted so much during adjustment that one end of it was forced down into contact with the slide base which, combined with the twist, made adjustment impossible. I ended up gripping the strip by its top and bottom in the milling vice so it was at 30°, flat-bottoming each dimple with a 3mm slot drill (and moving the out-of-line dimples over slightly) and making up new M4 adjusting screws with flat ends, turned down to 3mm over the last 3mm of thread. With a dowel at each end, the problems with adjusting the gib were solved.

Andy

[Ian PParticipant @ianp]

Gray

My mill is a Mentor. It has the Mentor plate fixed to the base casting so that pretty well nails it!

Interesting you mention the Spanish manufactured bits. I would never have even suspected that it was not all in-house Emco. From a quality point of view I would rate the base and slides as being noticeably better than the column and head parts.

The only bad design feature of the base is the positioning of the Y axis locking screw/lever. When I bought my machine the Y axis gib was bent because a previous user had tightened the lock whilst the gib strip was in mid air. I have moved the lock to a position where the slide is always fully engaged. Incidentally the front most gib adjusting screw bears on the end the gib that is always in fresh air anyway (but as you say gib stiffness still makes it a valid adjustment.

Ian

 

 

Edited By Ian Phillips on 27/03/2013 20:18:43

[Ian PParticipant @ianp]

Thanks Gray

I presume when you mentioned a 10mm needle race you meant a thrust race?

Ian

[Ian PParticipant @ianp]

Gray

Your work is very impressive, photography is not bad too! I now know the meaning of amateur, which my efforts certainly are by comparison.

The steel parts look like they are ground all over and have never been handled. Is the ball handle chrome plated or is it just polished?

I lust after an FB2, the pinion looks so much more substantial (larger diameter) than the earlier mill.

I assume the bronze pegs expand radially when you tighten the end screw, do they then grip by friction or do they engage in holes? With the two stages of gearing how much quill travel does one rotation give?

[Ian PParticipant @ianp]

Gray

Its not clear where does the motor fits in relation to these parts, It appears that you will have a worm on the motor shaft, but then what?

Youy are still modest. There are trained toolmakers, and there are trained toolmakers, they can be worlds apart though!

Sorry to hear you not fully well, I hope you recover quickly.

Ian

[ray jones 1Participant @rayjones1]

 

Hi, I have modified my RISHTON mill, which is very similar to the ones listed

 

It is fitted to a MYFORD 254 .

I had four parts to make,

1/ the clamp for the quill.

2/ the base for the slide..

3/ the slide itself.

4/ the reader head base to hold the magnteic pickup.

The reader head is then connected to a spare port on my 3 axis DRO .

My DRO is accurate to 5 MICRONS, – 2 tenths of a thou..

 

l

 

front of mill showing quill clamp

 

 

side of gearbox showing slide, reader head and base holding sensor tape

 

DRO showing quill setting 0.5000.

 

Edited By ray jones 1 on 05/04/2013 23:34:16

Edited By ray jones 1 on 05/04/2013 23:35:16

Edited By ray jones 1 on 05/04/2013 23:35:52

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