# Microlux 7x16 - finally usable



## ThinWoodsman (Jun 13, 2019)

I've made no secret of the fact that I was displeased with the 7x16 mini-lathe I bought from Micromark three or so years ago. It and the Taig micro-mill were so disappointing in their capabilities that I built a machine shop in the barn just so I could have some full-sized machines.

The 7x16 has been in pieces since early spring, when I took a stab at increasing the rigidity by doing stuff like stoning the bearing surfaces. Today, I bit the bullet and re-assembled the thing. Made a center height gauge from a foot-long bar of roughly 1" diameter aluminum, and things went swimmingly. This is, to date, the first time I have been able to hold a measurement on that POS lathe.

One modfication I made last year and only just now tried out is a carriage lock:





This is two Ts made out of bronze. The top one has through-holes for some bolts; the tailstock end of the carriage was drilled and tapped for these bolts (10-32 probably, I tend to use that a lot). There is also a through-hole for the bolt that connects to the bottom (inverted) T, which is drilled and tapped. A quick turn of the bolt and the carriage is locked. I was going to put a second bolt in the opposite way: clearance hole on the bottom T, drilled and tapped hole on the base of the top T. The two Ts did not line up the way that measurements from the end of the bed said they would (that is some seriously irregular casting under them ways), so there was no room for the second bolt, though it would improve things greatly.

The reason I mention all this is that the installation of this carriage lock did more to stabilize the carriage than any other improvement. It seems to fix the inherently bad design of the carriage gib strips. Or maybe removes some flex from the carriage.

I used to have the problem that the carriage would lift enough to raise the tool above center (presumably - the tools would start rubbing instead of cutting) when taking any cut, and tightening the gibs to the point that the carriage locked would not solve the problem. Really, really bad design - the base of the carriage is higher than the underside of the ways, so that when the gibs are tightened, they are at a downward angle, meaning most of the bearing surface is lost and only the area around the screws is making contact.

I am now satisfied that this lathe is usable, and indeed spent another hour or two just doing things like making washers. I do not take back every bad thing I said about this particular style of mini-lathe; in fact I am more convinced than ever that the design is fundamentally flawed. Apparently it can be fixed, though.


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## markba633csi (Jun 14, 2019)

Glad you got the lathe going- what did you find lacking about the Taig mill?  
Mark


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## ThinWoodsman (Jun 14, 2019)

The main problem I had with the Taig mill is the lack of rigidty. This was much easier to overcome than the problems with the lathe, though. I ran some 3/8" threaded rod down the main column and through the bench that the mill is bolted to, then put fender washers and nuts under and over so that the column is now cinched in place. I no longer have to tram the mill after taking a heavy cut in aluminum.

There are a couple of improvements I still need to make (end mill holders to use instead of collets, and a Z-axis lock that isn't just tightening a gib screw), but for the most part it is okay. I have been able to cut mild steel with it as long as the cuts are very light.


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