CNC Machines and/or CNC Conversions?

VacuumsChipsOften

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Hello,

Do any members have experience regarding CNC, specifically CNC conversions to existing machinery such as milling machines? Could you recommend one conversion kit over another in terms of ease-of-use and quick set-up (ie: going from a manual milling machine to CNC with ability to mill using g-code or manual inputs to the computer to specify hole locations)?

Thanks in advance for your help,

Eric
 
Good evening,

Thanks for replying to my post, there's quite a lot of good info in your reply!

I'm putting out the feelers on CNC with several possibilities for expansion/upgrades. I have some options to consider, namely: 1) sub-contract any work that requires multiple parts suitable for fabrication or machining by CNC or other automated machinery, 2) continue to build prototype parts and tools using conventional milling lathe-work, 3) convert some of my existing machines to CNC or other automation strategy, or 4) biting the bullet and purchasing a turn-key CNC machine, most likely starting with a CNC mill as my current milling machine is my most-often used machine.

Each of the above options comes with either a time or money penalty or both. With some additional time, internet research and perhaps one or more responses from prospective manufacturing companies regarding quotes on my parts, I should be in a better position to assess which strategy, or combination will work for me.

I'm currently running a manual mill sold by Busy Bee tools (see photos). It has DROs for the X and Y axis (scales routed to remote displays, all battery-powered which kind of sucks but seems to do the job for the most part). The DROs are an incredibly worth-while investment and are the first thing I strongly recommend a prospective mill owner install after purchasing their machine! They make life so much easier!!

I also own and operate Busy Bee's 9x20 lathe and 4x6 band-saw. I've attached photos of the band-saw showing some of the mods I've done.

DSCN4140_SCALED.JPG DSCN4146_SCALED.JPG DSCN4147_SCALED.JPG DSCN4148_SCALED.JPG
 
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Hi dalee,

Thanks again for your thoughts regarding CNC. Input from someone with clear experience (both good times and bad) is definitely needed in my situation. I stand to lose a lot of time, money or both if I'm not careful with my projects.

On the topic of time spent doing all the manual work myself, it took me 1 1/2 hrs tonight to mill some key-ways in six 1/2" shafts. This was after I spent last night figuring out how to mill the key-ways and building a shaft holder. Attached photos should help, I know I'm not supposed to set-up a square block of aluminum like that but I needed something quick and a pair of parallels did an adequate job of holding the aluminum at 45 to the end-mill. I made the vee cut pretty slowly, realizing that point loads on the vise jaws aren't good either. Aluminum probably isn't the best choice for a holder given its softness but seems to work ok after cleaning out the chips after each keyway is cut. Slow going with this mill, lots of chatter!

For anyone curious, my current project is a mobile robot. I'm working towards a prototype that I can use to test its strength, agility and other characteristics in addition to having a real-life piece of hardware to demo to prospective clients.

Once built, I hope to be able to engage several production companies to fabricate all the various pieces I require, in addition to an assembler/systems integrator as well as distributors/vendors. Or perhaps one company out there already has these components which will hopefully make my job easier...

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You'll gain rigidity by laying the shaft in the vee or even the table slot and clamping it. You don't have enough pressure into the vee that far from your clamp. Using woodruff cutters is a good way to cut slots, but you do need a rigid setup. Guessing at the size of shaft/cutter and length of cut, you should be able to make that cut in less than 2 minutes. Coolant or lube would help. What was your spindle speed?
 
Hi Tony,

I used a cutting/tapping fluid at approximately 675 RPM. Switched to oil after trying the water-soluble stuff that didn't work so well.

I rigged up something quick since I wanted just a few of these shafts keyed for my prototype. In the unlikely event I find myself needing to key more shafts in the future I'll want to look at a more rigid set-up as you mentioned. I'll also try to research the correct speed and feed-rate, although my feed-rate won't be known that accurately since I don't have a power feed.

Thanks again for all your help,

Eric
 
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