New Mill – Starter Tooling

[Neil WyattModerator @neilwyatt]

I've got a Warco 80mm swivel base vice and , to be honest, the base only uses up about 20mm of headroom.

Neil

[Ron LadenParticipant @ronladen17547]

Once I receive the mill I will check the gibs and the backlash and adjust if necessary, hopefully it will be ok.

I,ve watched a few videos on how to carry out the tramming of the table to spindle. One video I watched on a Chinese mini mill showed a 12 thou run out across 12 inches (6 inches either side of the spindle) in the X whilst it was 2 thou front to back in the Y. I,m hoping mine will be better than that, it would seem that the most popular method of correcting any problem is to shim the column to the base. I was thinking about that and though it will correct the run out, surely you lose the full face contact between the column and the base casting as the face of the column is bridged across the shims. Wouldnt that be losing some rigidity or am I wrong..?

Edited By Ron Laden on 14/10/2018 11:00:53

[Philip PowellParticipant @philippowell34749]

Posted by JasonB on 13/10/2018 09:15:32:

Sorry its the "versatile" not universal as I called it.

I can vouch for those Arc vices, I've had mine a couple of years now and very pleased with it too. I first baulked at buying it because it seemed too cheep, not quite up to Kurt standards but for the home workshop a great vice.

First thing I did with it was to remove the swivel base which gives a bit of weight to the stand and gave the machine a bit more headroom under the quill.

Phil.

[Ron LadenParticipant @ronladen17547]

Thanks Philip, thats good news as I have just ordered one

Ron

[JasonBModerator @jasonb]

I've had a bit of feeler gauge under one side of my mill coloumn, does not seem to have hampered me.

[Neil WyattModerator @neilwyatt]

Having scraped the mounting bracket for my X2, I would recommend shims…

Neil

[Ron LadenParticipant @ronladen17547]

Thanks guys, does the column to base have dowel pins as well as the fixing bolts..?

[JasonBModerator @jasonb]

Does on the SX2.7 and X3 but not sure about the SX2P

[Ron LadenParticipant @ronladen17547]

Should anyone be interested I watched a video last night on youtube of a German guy who trammed his mill using high quality metal filled epoxy and soft copper wire, no shims. If you go into youtube and do a search for tramming a mill with epoxy it will come up. I thought it a great idea and easy to do, if I have to do mine I would certainly give it a go.

[Neil AParticipant @neila]

The SX2P just has the four M8 fasteners holding the column to the base, no dowels.

If you think about it a small angular movement between the column and base has no effect on the vertical axis of the spindle.

[Ron LadenParticipant @ronladen17547]

Posted by Neil A on 15/10/2018 11:28:43:

The SX2P just has the four M8 fasteners holding the column to the base, no dowels.

If you think about it a small angular movement between the column and base has no effect on the vertical axis of the spindle.

Thanks Neil, though you have lost me there, surely it has an effect on the relationship between the spindle and table.

[Ron LadenParticipant @ronladen17547]

I have read that ER collets have some variation in their size and can be used to hold work/tooling which is +/- to a certain degree, I guess the same is not true of finger collets..? I was just wondering if my dial gauge post at 9.78mm would hold in a 10mm finger collet.

Edited By Ron Laden on 15/10/2018 13:32:59

[not done it yetParticipant @notdoneityet]

No, they are for discrete sizes only. ER usually cover approx 1mm or 0.5mm range depending on the supplier and ranges offered.

You dial gauge might be held adequtely, but not a working cutter.

Edited By not done it yet on 15/10/2018 13:39:49

[Neil AParticipant @neila]

Just to clarify my thinking

If the spindle is truly vertical then rotating the column on its horizontal flange will not effect the vertical axis of the spindle, only its position in the X and Y axis above the table. Hopefully the horizontal faces of the column and base are parallel to the top of the table otherwise there will be some effect, albeit small. Rotation is limited by the clearance in the setscrew holes.

Sorry to cause confusion, should have stuck to saying "no dowels".

[Ron LadenParticipant @ronladen17547]

Neil, I understand what you were meaning now, sorry just me reading something else into it.

Ron

[Ron LadenParticipant @ronladen17547]

Well probably been asked dozens of times but having no experience with a mill I need to ask it again. The correct use of the drawbar..? My mill spindle is R8, I understand how to fit the collet and tool but how tight does the drawbar have to be, I dont want to over do it. Plus removing the collet, do the drawbars always require a tap to release it.

[Mark Elen 1Participant @markelen1]

Hi Ron,

I’m glad you’re asking this, because I’ve got a R8 collet on it’s way for a project I’m working on. The only experience I have is with an ER25 collet Chuck. I find that the drawbar always needs a tap with a rubber mallet to release the Chuck.

The problem with the Chuck is that it takes up 2” of room that I need to machine a long part, so I’m going to try a finger collet.

I’ve had no problems with the ER collet Chuck, although, I always tighten it up pretty tight on the cutters and I don’t think I’m pushing it overly hard.

Cheers

Mark

Edit: forgot to say, to add to your list of tools, I found I can’t be without a set of parallels. I’ve got one of those Arc versatile vices, good bit of kit for the price.

 

Edited By Mark Elen 1 on 15/10/2018 22:41:19

[Ron LadenParticipant @ronladen17547]

Thanks Mark, thats helpful, I feel a bit guilty asking questions which much seem obvious, but with no experience on a mill I just dont want to get off on the wrong foot. I was pleasantly surprised at the cost of the R8-ER25 chuck and with 18 collet sizes available at just over £5 each you can build up a set to suit the tooling as you go along, well thats my plan anyway.

Ron

[Anonymous]

Posted by Ron Laden on 15/10/2018 20:22:50:

……… but how tight does the drawbar have to be, I dont want to over do it. Plus removing the collet, do the drawbars always require a tap to release it.

I do mine up pretty tight; a good hard push on a ring spanner. Remember that power transmission is entirely through friction of the mating spindle and tooling tapers.

I probably tighten more than most people for several reasons:

On both my R8 taper mills I use the Tormach TTS system which uses a 3/4" collet and tool holders with a plain 3/4" shank. So the collet needs to grip the plain shank tightly to transmit power

I often run my mills to the limit of the available motor power and I don't want to ruin work/tools/mill by having tools pull out or slip in the spindle

On the CNC mill the tool holders need to be pulled tight to the spindle nose for consistent tool lengths

I'm a master exponent of BF & BI

In theory the R8 taper is self releasing. In practise I find that a tap or two on the tool is needed, although by no means always. The TTS toolholders often just slip out, indicating that the collet has relinquished its grip.

Andrew

[Ron LadenParticipant @ronladen17547]

Thank you Andrew, that is exactly what I wanted to know, much appreciated.

Ron

[SillyOldDufferModerator @sillyoldduffer]

This is a bit 'suck it and see'. So much depends on how you drive the mill. Andrew has decent kit and time pressures so he pushes harder than I do with my relatively weedy equipment and 'for fun' production rates.

Two things you don't want:

1. A loose tool shank slipping inside the taper during cutting. This will damage the mill.
2. A tool shank pulled so hard into the taper that you have to hammer rather than tap the drawbar to remove it.

With MT (a different taper that always has to be tapped out), I don't tighten up much. Roughly hand tight plus a quarter turn with a spanner. Hand tight plus a full turn makes the tool much harder to release, requiring an alarming amount of pounding. Unlike the MT series I'm used to, R8 is meant to be self releasing. If it needs a tap, then it's a shade tight. Andrew does that deliberately, you may prefer to use your mill less aggressively.

In your position I'd tighten my biggest cutter in the R8 with the quarter turn nip up and then take a fairly deep short test cut in mild steel. There should be no sign of slippage. But the acid test is to remove and inspect the taper carefully for abrasion. If there is any, tighten up.

Don't fret too much, provided you don't develop a bad habit, MT is fairly tolerant. I've no direct experience of R8 but in theory it should be better.

Good idea to give tapers a wipe each time they go in and out of the socket. Dirt and oil increase how tight the drawbar needs to be.

Dave

[BazyleParticipant @bazyle]

I've never used R8 but be aware that there is a small pin in the socket and groove in the collet to stop it rotating as you initially tighten it. From time to time you see posts on forums about someone with a collet stuck because it slipped round causing the pin to cut a groove in the collet making it like a bayonet fitting. Probably more of a problem with a well worn pin and a monkey on the handles.

[Ron LadenParticipant @ronladen17547]

Thanks Dave/Bazyle, this is all good to know. New to all this I have been watching a lot of videos and it surprised me the different approaches people take to fitting or releasing with the draw bar, thats why I asked the question. I think most seem to get it hand tight and then a quick nip with the spanner but one or two I have seen really tighten it down and not on serious kit like Andrews but on mini-mills. Likewise with releasing the tooling, some a light tap others a bit more with the odd one hammering to the point of it been scary.

Anyway I am sure it will all come to me in practice just wanted steering in the right direction.

Ron

[Ron LadenParticipant @ronladen17547]

After a long time waiting I am now the proud owner of a mill, its installed in the shop and ready to go, well almost.

I broke the machine down into two parts removing the column from the base and that made it manageable, well just.

The seller didnt exaggerate when he said it was in good condition and little used, you can see that by just looking at it. Impressed with how quiet the brushless motor and belt drive is, seems very smooth.

With the base/table assy free of the column I took the opportunity to adjust the X and Y gibs, I spent quite a bit of time doing it and they are as good as I can get them, its left the X hand wheel a little stiffer than it was but its ok. There is about 5 thou of backlash in both the hand wheels which is better than I expected. The backlash on the spindle fine feed dial is about half a turn but apparently there is a quick fix which improves it.

With the machine back together I set up the dial gauge in a collet and trammed the table. Checking 5 inches either side of the spindle in X there was a 4 thou difference, 4 thou over 10 inches I didnt think that bad. However in Y there is an 11 thou difference from the table front to the rear over 5 inches. The column is leaning forward or I wonder is it..? I havnt checked the head gib, could it be possible that the error is there, what do you guys think..? If it is the column to base I will set too and adjust it.

The vice arrived from ARC, it looks good, thanks Jason for pointing me to it. Also a couple of end mills and collets arrived so at least I can make a start and get in a bit of practice.

Thanks guys for all the help and advice you have given me, it really is appreciated.

Ron

[not done it yetParticipant @notdoneityet]

As you mentioned backlash in the same paragraph as gib setting, please be aware that the two are not (necessarily) connected. Backlash in the lead screws cannot be sorted by tightening the gibs.

Also, do remember to use a soft hammer or mallet, not a steel one, to tap any shaft in these type of bearings

If tight, I often use wedges to loosen my MT tool holders.  Available from AET, or can be made yourself.

Lastly, don’t fit colder taper tooling into warmer taper sockets. Expansion/contraction will make your life more difficult. Likewise a hotter inserted taper may loosen, if fitted to a cold socket.

Edited By not done it yet on 17/10/2018 17:00:56

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