Hi all,
Been thinking of getting a small mill and had thought of going for an x2/conquest/mini mill. I'm now wondering about the difference between this and the Warco ZX-15/Champion.
Anyone care to pass comment?
Ta
The biggest issue with these mills is losing accurate location with round column models. When you need to raise or lower the head or adjust the height to change a tool or similar they can pivot slightly on the round column and then you find the cutter centre has moved. Mills with a dovetail slide for the head or the knee will not usually have this problem, but they are of course more expensive. However the current issue of MEW (issue 108) does offer a solution for this problem. In the right hands they can be a very capable small machine, just look here
Peter
Sorry - just realised that didn't answer your question at all.
Peter
No experience of the ZX-15, but here's some observations on the Sieg X2 I've had for about 3 years.
GOOD
NOT SO GOOD
Some of the less desirable 'features' can be worked round.
The plastic gears don't fit any recognised DP or module gearing, but if you are feeling brave it's possible to make replacement metal gears. Only do this if you are completely deaf and have no neighbours, otherwise keep a set of plastic gears spare (they're cheap and quiet).
Many problems arise with heroic use - lighter cuts within the machines capacity will result in accurate and reliable work.
The only way to deal with the fine feed issue is throw the fine feed away and replace with a ballscrew, or install a DRO.
Either pin or glue the column to the base after the mill has been accurately trammed - I have't had the column move since loctiting it in place.
Mine now has a DRO, glue in a few places, and I've obtained a ballscrew which will be fitted to the Z axis. I know this will attract a few "silk purse" comments and that a 2nd hand Bridgy could be obtained for what I've shelled out, but there simply isn't the room for a large mill here!
I worked through this last year and ended up with a Warco Economy (which appears to be identical to the Chester eagle 25), these machines are robust, and have experienced just how massive milling forces can be with just a 12mm end mill, glad I didn't buy anything less. I'd guess you just couldn't get full use of a 12mm end mill on a Conquest.
Googling on the Conquest (in all its guises) you find all sorts of worries, loads of play in fine "z", a recommendation to epoxy the the column in place and buy a new set of plastic gears. I almost bought the ZX-15/Champion but worried about the very limited range of speeds and the bottom speed was fairly high from memory, limiting the diameter of fly cutters.
The round column thing has never caused me a problem, because I'm not doing anything particularly serious with it (I've made a new top slide for my lathe with 45deg dovetails was about the most difficult set up to date, not wanting to buy a 45 deg cutter for only one job).
Biggest problem for me is that the M3 taper can stick and be a bugger to free off and I've read in this NG that the R8 taper (of which I've no experience) doesn't.
A year on if I was making the same decision again, I'd probably go for a square column mill with an R8 taper, but I don't regret buying the Warco.
Steve
Hi,
I bought a Warco ZX-15 about a year ago and am pleased with it.
Some minor problems such as the thrust adjustment on the leadscrews working loose but easily fixed.
I thought the tilting head may make it more useful than the standard mill/drill models but, having set it square with I dial guage, I have yet to tilt it.
It seems to be quite robust and the table travel is better than many small mills and can be increased further (see MEW 101).
I have not had problems with the round column (other than when I didn't clamp the head tight enough} but sometimes you have to think ahead to avoid losing the head location or arrange to be able to reset it with a dial guage.
My only real complaint is the high bottom speed so a future project is to add a variable speed drive.
Russell.
Thanks all for your replies.
Simon
As usual, I can't find a retailer with MEW in stock.
But I'm interested to know what solution is suggested - maybe it's worth going to the backnumbers service.
I have a Westbury-Dore mill and although the round column hasn't been a problem so far, I haven't used it a great deal and I'd like to have a solution to hand for the time when it annoys me.
-adrian
I could scan & mail the article if you like, providing of course that no-one raises any strong objections to me breaching the copyright...
Peter
Peter Neill wrote:
No, I'm quite happy to buy a copy or may be able to borrow one eventually. I'm just interested to know the general idea of what they've done : added a keyway perhaps, or some sort of alignment aid ?
-adrian
It's a vertical guide bar, mounted to the column at the base with a split bracket, with a pillow block type arrangement fixed onto the head, and has retained registration to 0.001" apparently. There is another idea here
Peter
Adrian
The usual 'fix' is to screw the vertical rack, which usually sits up the length of the round column, to the column itself. This provides a crude register against which the head can be pulled prior to re-locking. The keyword here is 'crude' - repeatability is very questionable to any degree of accuracy.
I remember that a Frenchman wrote an article for Model Engineers' Workshop , perhaps four years ago. --
Chris Edwards (in deepest Dorset) ..."There must be an easier way...!"
Thanks, it sounds worth a look to see if I could adapt it.
The metalmaster scheme is also interesting but cutting the triangular groove in the column would need another, bigger, mill.
-adrian
I have a spiral jacking groove rather than a vertical rack, so would need a different method.
-adrian
"Planning is an unnatural process - it is much more fun to do something else - and the nicest thing about not planning is that failure comes as a complete surprise, rather than being preceded by a period of worry and depression".
Sir John Harvey Jones
I looked at the article and there was a fair bit of work sorting out the top.
Presumably it could be made more simply by using a slot and gib arrangement at the head so that the only precision component is the base bracket.
- Stewart
I've got hold of a copy now. It's not directly appropriate to my mill, which has a column that slides into the base rather than a head sliding on the column. It's possible that I could put it upside-down, with the pillow block on the base and the bar fixed to the head.
I'm surprised, though, that it achieves the quoted accuracy - I considered this approach but thought it would be difficult to mount a bar parallel to the column that didn't wave around at the free end.
-adrian
I've just been hit by a bit of lateral thinking (quite painful).
Mount a pair of pieces of ground steel or a linear slide under the base parallel to the column. have a platform run up and down the slide/silver steel attached to a collar on the bottom of the column. Use a rotary encoder, probably geared up via some anti-backlash gears, to detect the column angle.
If any of that made sense, the idea is to forget about retaining accurate registration, but to enable measurement of the column angle so that, after jacking the column up or down, you can return to the angle you started at.
Mark Rand RTFM
If you are going optical, I wonder if you could do something with a laser attached to the head to reset the angle.
Stewart
I've seen that suggested before - someone put a laser on the head and noted the position of the spot on a far wall. After realigning the column, the spot should be in the same horizontal position (though it might be vertically displaced).
I see Morrisons have laser levels for ?4.99 at the moment ..
-adrian
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