I'm pondering buying one of these for incidental hobby use. Typical materials will be brass, bronze cast iron. I can't envisage a requirement for cutting titanium or hard steels.
Its about the biggest machine I can manage in my garage and I don't have the skills to inspect/refurbish precision machines, so I don't intend to venture into the secondhand market, a decision advised by a toolmaker of no mean reputation.
This Mill looks identical in the catalogues to mini mill Warco have on offer, but I haven't compared them "in the flesh".
Are there any material issues I need to be aware of with this machine (I'm comfortable with Chester's service performance)?
How does the machine spec "as used" compare with "as advertised"?
Get a machine where the entire Z-travel is controlled by a single lead screw, even though this is irritating to wind from one end to the other.
Some of the lower-cost mills have an imperfect Z travel.
You may find that the range of lead-screw Z depth is limited, and when you release the Z carriage, to move it a greater distance, that it swivels around the post losing your XY registration.
I'm afraid I'm not very conversant with these things.
Are you saying some of the Conquest mini-mills have imperfect Z travel and there are different grades of Conquest mill I can buy to avoid this problem?
Steve, I have one of these machines and there are a few things you need to be aware of:
(1) Z axis location. This is a dovetailed column made from a cast iron box section, and quite solidly built. It is secured to the base by a single large nut to allow the column to tilt +/-45 deg from vertical. However, major tool dig into hard material will cause the column to knock itself away from the vertical. If you are feeling brave and don't need the tilt "feature", you could use slow set epoxy to glue the column to the base although I haven't done this yet.
(2) Z axis feed. Up/down movement is controlled by a rack attached to the column and a pinion operated by the three-legged control in much the same way as a drill press. For fine feed, a worm gear is engaged on the pinion shaft through a very loose universal joint. Adding up all the backlash in the rack/pinion, worm/gear, and universal joint is nearly 0.060" (1.5mm) which will get you a nice tool dig unless the gib is locked and cause problem number (1) and (3). I have a 1" dia ballscrew + nut here from a US Ebayer which turned up at the right price, and this will replace the rack/pinion and all the other crap. It's going to need some castings making up etc., and is not a trivial job although will make a big difference to the performance of the machine.
(3) Plastic gears. The high/low transmission is carried by plastic gears. Any problems, and these will shatter - guaranteed. I did start making steel gears, but the whine was out of this world. Helical gears won't work, as they will pull the machine out of gear :-(
For spare parts, I found Chester to be disappointing in terms of price and performance. Recommended source from me is
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who carry all the spares for these and are much cheaper (although being American, all the electrical items + fuses are meant for 110V supply).
Another site that may interest you is
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which has a lot of pictures of this Chester/Warco model under various US brand names.
Don't be put off too much by all the stuff above, it does have its good points such as continuously variable speed, chip guards, solid cast iron construction. You can even get round the Y axis feed problems by locking the gib tight, although I'm after CNC on that axis so it's a no no for me...
For your stated usage it's probably OK, though I see Duncan has already pointed out some pitfalls. Installing a 5/16" dowel pin would prevent the head moving away from vertical (I did this with my Warco but for the reason of quickly re-setting the head to vertical). I don't know why they put a 3MT spindle taper in such a small machine,
2MT would have been more suitable. Then again, you can use a sleave I suppose. Given the problems with vertical feed (backlash) I'm not sure how useful it would be for boring - anyone tried using one for that?
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