I've had a harbor freight mini mill for a number of years now and converted it to CNC about 3 years ago. Overall I'm happy with it and would encourage you to go ahead with the following caveats and comments: 1. Yes, it's not a Bridgeport (I've used one), but dang!, its a fraction of the price, it doesn't require 3-phase power, and it fits on a bench in my basement. I've used it for a bunch of projects and have not suffered significantly for any quality issues.2. Essential extras you will need: a. VICE - careful on the size (not too large) - I think the one I have is the cheapest 3" one from LittleMachineShop. I had to remove the rotating base otherwise it was too high of the x-table. b. PARALLELS - for positioning smaller pieces in the vice. LittleMachineShop sells a nice set, but I made my own out of aluminum. c. Hold down hardware - need this for vice, etc. d. Cutters - an assortment 1/8" to 1/2" e. Collets - I'm embarrassed to admit this, but I've done fine with the 1/2" chuck that comes with it. f. I notice that LittleMachineShop has all this in a tooling package for ~$250 g. DRO. I did this before adding CNC. Personally, I can't imaging trying to make things on the mill without some sort of digital X-Y display. Using the scale on the cranks is just too painful! OK, CNC both gives you a backlash free position AND moves there, but unless you need complex shapes or rounded outside corners, most things can be done manually with DRO's. I mounted a 12" on X and a 8" on Y. LittleMachineShop sells a MUCH nicer setup that I had for $89 (12")!
CNC1. I followed Hossmachine_Cnc Conversion . I added X and Y and have as yet not Done Z2. He provides excellent drawings and photos. The main deal is to replace the X and Y lead screws with Ball screws. The mill has to be taken apart and some serious grinding done on the castings. This turned out to be less daunting that it initially appeared. HOWEVER, the ballnut mountings need to be made before you build it otherwise it you can't put it back together. Actually, most of the pieces need to be done ahead of this step. This is why I recommend a DRO.3. Motors/power supplies/drivers/Mach3. This is well documented and straight forward. My 2-cents: Get the mill. Spring for the tooling package and 2 DRO's. As a first project mount the DRO's and get a feel for working with the system. Then maybe CNC. | | | | | | | | | | | Hossmachine_Cnc ConversionGet Your Motors Spinning | | | | View on www.hossmachine.info | Preview by Yahoo | | | | | From: Jason Barnett <[email protected]> To: "[email protected]" <[email protected]> Sent: Monday, March 2, 2015 12:25 AM Subject: [dorkbotpdx-blabber] Can anyone talk me out of this? I have been toying with the idea of getting a cheap desktop "mini mill" for some time. I think I am finally ready to pull the trigger and buy a harbor freight 44991 mini-mill. It's reasonably priced for the little bit that I will ever use it and there are a ton of people that have hacked them into CNC machines. This sounds like a fun project sometime down the line.My question is this, is there anything I am missing that should change my mind? I know it is a very low end mill, but for my needs (cutting notches in aluminum extrusion, making aluminum stepper motor brackets, etc) I think the accuracy is good enough. I can get one for ~$500 delivered + a bit for some mill ends.Has anyone had experience with this mill or with doing the CNC conversion that can give me an opinion? _______________________________________________ dorkbotpdx-blabber mailing list [email protected] http://music.columbia.edu/mailman/listinfo/dorkbotpdx-blabber
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