I'm not sure I would recommend an X3 type of mill for what it sounds like you want to do. I consider it to be a rather light duty machine. I have an earlier tilting column version of this sort of mini mill and feel it is marginal for machining other than rather small parts, especially if machining tough materials. You can do it, but it takes much more patience and more aggravation. I also have a larger knee mill (along the lines of a Grizzly G0801 but of a different era and manufacturer) and also a lot of machine shop time on a small Clausing 8530 (which is pretty small machine as industrial machines rate but far more substantial than any mini mill.) So I have my reasons for recommending against the X-3 for anything that might be perhaps a more "industrial" sized need.
As an example, here is a selection of some machines from what is likely the best mini mill, to a bench top version that is likely far larger than what you need. You might consider making your own comparison chart with the important specs of about as many of these things as you can find. Sometimes just a single specification might make the machine not suitable for you, so check carefully. (Spindle to Table distance is a good example to watch out for.) Usually, when you do that, a sort of "sweet spot" becomes apparent for your personal situation. You will get an idea what is too small or light and what is overkill.
Little Machine Shop 3990 HiTorque Mini Mill (probably the best of the "mini mills")
- Weight: 124 lbs machine weight (says crated weight is 161 lbs and in another description 176 lbs. But 124 lbs is in the specification list)
- Horsepower: 0.67
- Table size: 18.1" x 4.7"
- Max Spindle to table: Not given (X-3 described elsewhere at their site says 14 3/4")
- Price: $1154.73
Grizzly G0758 Mill/Drill (This is really the Grizzly "mini mill" I think)
- Weight: 204 lbs shipping weight
- Horsepower: 3/4
- Table size: 19 3/4" x 5 3/4"
- Max Spindle to table: 8 3/4"
- Price: $1150.00
Grizzly G0795 – Heavy Duty Benchtop Mill/Drill
- Weight: 496 lbs shipping weight
- Horsepower: 1
- Table size: 27 1/2" x 7 1/2"
- Max Spindle to table: 16 1/8"
- Price: $1895.00
Grizzly 0720R Heavy Duty Benchtop Milling Machine
- Weight: 768 lbs shipping weight
- Horsepower: 2
- Table size: 32 1/4" x 9 1/2"
- Max Spindle to table: 15 3/4"
- Price: $3950.00
In just the above examples, the Grizzly G0795 would appear to be a massive jump up in beefiness and size compared to the increase in cost. To be a little silly about it, that Grizzly G0795 machine is $3.82 per pound versus $7.17 per pound for the Little Machine Shop mini mill. Or maybe that's not so silly after all.
Chuck K.
Sent from Mail for Windows 10
From: Rex Burkheimer burkheimer@gmail.com [GrizHFMinimill]
Sent: Thursday, March 14, 2019 8:35 AM
To: GrizHFMinimill@yahoogroups.com
Subject: [GrizHFMinimill] Re: Newbie w/questions
Geared- head mills (and lathes) are generally preferred because they deliver full torgue all the time. That's never been a concern to me. Every mill I have had has been belt drive except my first X2 minimill years ago. Nevertheless, there is a price premium when new, and they do sell.
I would not let it affect the buying decision, and I would not pay any premium.
Here's where that round column becomes an issue: Say you just drilled a hole with your short drill bit, and now you need to tap it without losing position. You raise the quill all the way and still can't get your tap holder + tap in the available space. Now you have to unclamp the head assembly from the column and crank it up. In the process it can rotate around the column a little, losing your position. There are workarounds. This has only been an issue on a very few of my own projects.
As to a power reduction when using a VFD, that is not the case with modern drives. A 3-phase motor with a VFD is a great way to power tools. However, you do need to factor the VFD cost into the total.. Add $200 and you are now at $1200, That is about the very most I would consider if there are no other good choices locally.
For that money, I would probably be looking at one of the X3 variants instead, like a G0704. You can get close on price buying new.
I recently bought one of the LMS Hi-Torque minimills. That is a very nice small mill, with a rigid column, more power, and a larger table than the regular X2s. If your work fits the envelope it's worth considering. Not sure if Grizzly has a comparable model.
Rex B - DFW
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