mini-mills

[idleprocess]

I know that lathes are generally the preferred machine tool around here, but there have to be a few that use mills. The projects I want to work on are best done with mills anyway.

I've always been interested in this mini-mill (This appears to be the same mill mentioned in a recent manual-CNC thread). After a trip to the local Harbor Freight store and examining the floor model, I'm convinced that it has potential.

The only shortcoming I noticed immediately was that there's some play in the gear rack that controls Z-axis motion - perhaps because it was a floor model that's been abused without maintenance for years?

All the other mills I looked at had problems - the head was obviously a drill press, they were multifunction mills/lathes, or the quality was poor.

Comments?

I'm a long ways from being able to afford a mill, but don't mind planning ahead.

 

[Rothrandir]

my hf lathe has always had a bit of play in the crosslide and compound, so i wouldn't be surprised if the mill you mentioned was the same way /ubbthreads/images/graemlins/frown.gif
that can be reduced, but not necessarily fixed though...

 

[gadget_lover]

Yeah, I keep lusting over that one too. The display model at my local HF store has been very abused. There are missing levers and worn parts. I just don;t have anywhere to put one.


Daniel

 

[Rothrandir]

[ QUOTE ]
gadget_lover said:
Yeah, I keep lusting over that one too. The display model at my local HF store has been very abused. There are missing levers and worn parts. I just don;t have anywhere to put one.


Daniel

[/ QUOTE ]

hey, i've got a place you can put it! /ubbthreads/images/graemlins/grin.gif

 

[unnerv]

The mini-mill does have some play due to the way the the fine feed engages the rack on the z-axis. It can be worked around though. Take a look at this link. There is a lot of good info about the machine.

 

[gadget_lover]

You know, Roth, I expected the LOCAL flashaholics to offer bench space. There are actually three of us in one town. Iowa is too far to commute when I want to mill a part.

I've seen Unnerv's, and I've seen a little of what it can do. I am suitably impressed. Now if they would just sell the talent to use the thing, I'd be tempted to make space.

Daniel

 

[Mednanu]

The mill you are looking at is actually from a class of entry level mills sold under various manufacturers' names. Each manufacturer generally has a slightly different version of this same mill available to them. While the differences may be subtle, they may also have a siginificant impact on how you do your work ( ie - accuracy of the compound table, whether or not it has Head-tilting capability, etc ). You can compare each of the different models within this family of Mills at this link, here .

I actually wouldn't go with this version due to the fact that the head doesn't tilt 45° like the some of the other models do. That can be a big deal when you need to drill into the stock you're working on at a precise angle. It's also a little less accurate on the X>Y axis adjust wheels than say the Micro-Mark version. If that will adversely affect your work, you may wish to purchase one of the other versions that better fits your needs.

 

[idleprocess]

The HF mill can tilt the head along the X-axis - but by most accounts I've read it's not really recommended due to the difficulty of assuring precise positioning. Most of the opinions I've read strongly suggest using a vise with angle capabilities instead.

Micro-Mark's mill uses 20 TPI leadscrews for positioning - much easier for machining stuff in inches and greater granularity than the typical 16 TPI leadscrews.

I'm very impressed by the CNC conversions I've see on this mill.

 

[tvodrd]

Using sine bars/adjustable angles in the vise for angling the workpiece is typically preferred. (At least by me.) It saves having to re-indicate the head square with the table, which can take 20 minutes to really get right. Also, for whatever reason, /ubbthreads/images/graemlins/grin.gif I prefer an R8 spindle. I'm a little giddy as a used, 2HP vari-drive Series I Bridgeport landed in my garage a couple weeks ago, and a serious lathe is due tuesday. /ubbthreads/images/graemlins/grin.gif

Larry

 

[McGizmo]

/ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/grinser2.gif

 

[tvodrd]

/ubbthreads/images/graemlins/nana.gif

 

[gadget_lover]

I just bought a nice precision screwless vice (also seen as a tool maker's vice. It works quite smoothly, and I'm looking forward to using it. I can't quite figure out what the extra little bar is or when I should use it.

The model is 505-2143 (currently on sale for $44.99).

Thanks,

Daniel

 

[rwolff]

[ QUOTE ]

I can't quite figure out what the extra little bar is or when I should use it.


[/ QUOTE ]

Questions about a Toolmaker's vise? Ask a toolmaker! (Note that "vise" is a tool, "vice" is an issue of morality.)

By "extra bar", do you mean the dowel that's visible between the vise body and the allen key? If so, here's what it does:

Turn the vise upside down. You'll see a short dowel (held by a setscrew) that fits into transverse grooves. The transverse grooves are "sliced open" holes drilled through the base. You'll notice that the "extra" dowel is the same diameter as the one that's already installed, but it's long enough to bear on the "solid" parts of the row of holes in the base.

Some toolmakers prefer a "fixed" short dowel because there's no need to remove/install parts to make a large movement of the jaw. Other toolmakers don't want to worry about losing grip because the dowel only went partway down into the groove (or slipped out without them noticing when they tightened the screw), and are willing to put up with the inconvenience of removing and installing a longer dowel whenever they make a large jaw movement.

There's no right or wrong answer - it's a matter of personal preference. Since dowels are cheap (relatively speaking), the vise includes one of each. If you're in the "short dowel" camp, put the long dowel in a safe place, and label it as to what it is (in case you change your mind). If you're in the "long dowel" camp, remove the setscrew and short dowel, put them in a safe place (again, labelled), and stick the long dowel through the appropriate (for size of object being clamped) hole in the base and the hole in the bottom of the "nut" (where you took out the short dowel).

 

[gadget_lover]

Thanks for the exlpanation Rwolff. That makes perfect sense.

I think my spelling might have been accurate. Whay you buy hyndreds (or thousands ) of dollars worth of accessories for a hpbby, it might be a vise vice.

Daniel.