Basically yes, benchtop machines use a moveable head instead of a knee.

They are sometimes described as 'mill/drills' although most aren't particularly convenient to use as drilling machines.

Neil

David.

For all practical purposes its 6 of one – half a dozen of the other. Moving head or moving knee gets you to the same place although the most appropriate machining techniques to be used may differ. Probably the least important consideration when choosing a machine.

Larger table and travels of the WM18 are attractive but rotating head of the VMC has certain advantages and may well compensate when it comes to workpiece coverage. Never used a small turret mill so I don't know. Bench mill lets you keep you standard under bench storage system, which can be considerable advantage in a small workshop, although it does put the top of the machine rather high. But then you don't have to stoop to look at the table. VMC plinth can be quite space inefficient.

Went through the same exercise many years ago comparing VMC against a Chester Lux style machine. Ended up with a one off Lux type with VFD drive and two speed belt transmission that worked well enough. Despite going round and round many times I never did decide which would have been best from pure machine considerations. VFD drive and bargain price swung it. By the time I'd added a proper DRO set and one or two other refinements what I had was very similar to a WM18. I see no reason why you'd not find a WM18 a capable and satisfactory machine within the limits of the design compromises inevitable in meeting a sensible price / performance ratio. Sneaking suspicion that the head and column may inherently be a little less rigid than knee style but you probably shouldn't be making cuts hefty enough to notice. I never had any stiffness issues.

I moved on to a Bridgeport because the bench mill was too small for much of the work I do. Not aware of any specific disadvantage or advantage of the knee relative to moving the head.

Clive.

Yes, same here. I’ve had two knee mills, currently using a VMC which has been very good.

I’d choose the VMC again any day over the WM18 but it’s a personal choice. I’d used several Knee mills before I bought my first one and knew I’d hate a mill with a moving head. If you haven’t used a mill before though you may get on ok with a WM18.

One thing that occurred to me some time ago is that I’ve never needed to lock the knee on my mill when making a cut, I just raise and lower the knee as required. There is considerable mass in the machine. On a moving head machine I’m thinking it’s advisable to lock the head before making a cut or can anyone confirm otherwise? Just interested more than anything else. By the same token I never move the quill when milling (to preserve rigidity) only the knee. The quill only gets moved when using the mill for drilling. Being able to rotate the head and swing it side to side on the VMC has been very useful over the years. Not as good as my old Omnimill but still very useful.

On several occasions I’ve needed to drill a hole in the end of a long bar. I simply clamped the bar vertically on the back edge of the table against an angle plate and then swung the head over above the workpiece. I also did this once or twice on my old Omnimill which articulates even better than the VMC.

I have a WM16 which is very similar to the WM18 under discussion. When taking a milling cut I don't lower the head to increase the depth of cut. I set the initial position of the head and lock it then use the quill fine feed mechanism and digital readout to lower the cutting tool.

Jim

Sorry, just skimmed this thread. But

You cant trust a head to drop just by dialling a cut size. I had a mill/drill by Warco and earnt a lot of money off it. Warco was excellent in their service back then and overall i was very pleased allround.

But drop the head by an indicated 20 thou and maybe get a 15 thou cut. So you are still up on size so you put the 5 thou on and the machine drops the 5 thou plus the 5 it didnt do last time. Its a common senario and not usually a major problem. But, if you had a knee, oooooooh the extra confidence you gain.

If you can afford it get one with a knee.

Look round for a lightly used second hand one of better quality.

Alan

I believe that the Z axis on that model is a rack and pinion which has a distinct backlash problem which can be fixed with a gas strut and I would recommend a DRO fitted to all three axis. I have just fitted an M DRO set to my smaller version and it has made it a magical piece of machinery.

David

Slipping belts on the VMC is really no bother at all to me but I know some like variable speed so the new model VMC is attractive. Good luck with whatever you decide to buy. Next you’ll be asking what milling vice to buy …