Cnc noob

[matthewsx]

Conversion kits plus the mill will get you near $4000,

I'm not seeing anything too special in either of the kits, maybe it's because I've been doing my own "conversion" but I really think you can build and buy everything in both those kits yourself for a whole lot less.

If I was going to spend that kind of money I would be inclined to look for a more capable machine, but that's just me....

Cheers,

John

 

[Livnpaintball]

Just reading up and do I need to go closed loop to consistent milling? Or is everyone getting good repeatability with the open loop?

 

[Boswell]

My system is open loop. I keep the acceleration conservative and don't push the cutter load and have not had any issues. Closed loop would be nice but seems overkill of a hobby system.

 

[matthewsx]

That's a question I was wondering about too, I'm not nearly close to testing repeatability but as I plan my upgrades I would like to purchase what I need once rather than stumbling through it. I'm lucky that the steppers I'm using now were gifted so I'm not loosing out when I replace them but would like to do it only once.

From what I've read, and people I've talked with (there is a CNC tool manufacturer in our little town) closed loop isn't really necessary if you have enough power to start with. It seems like loosing steps happens when you're cutting faster than the machine would like to handle. Of course I could be totally wrong about that since I'm only a little further along than you are.

I'm assuming you've read this thread where he's building almost exactly the machine you're planning.

New PM-25MV Mill

After getting some Christmas money and making a few extra bucks with a machining job, I decided to get a new milling machine. I currently have a Harbor Freight X2 that I have had for a little over 2 years now. I will be converting the PM-25 to CNC immediately. I intend for this thread to be...

www.hobby-machinist.com

Cheers,

John

 

[Livnpaintball]

That's a question I was wondering about too, I'm not nearly close to testing repeatability but as I plan my upgrades I would like to purchase what I need once rather than stumbling through it. I'm lucky that the steppers I'm using now were gifted so I'm not loosing out when I replace them but would like to do it only once.

From what I've read, and people I've talked with (there is a CNC tool manufacturer in our little town) closed loop isn't really necessary if you have enough power to start with. It seems like loosing steps happens when you're cutting faster than the machine would like to handle. Of course I could be totally wrong about that since I'm only a little further along than you are.

I'm assuming you've read this thread where he's building almost exactly the machine you're planning.

New PM-25MV Mill

After getting some Christmas money and making a few extra bucks with a machining job, I decided to get a new milling machine. I currently have a Harbor Freight X2 that I have had for a little over 2 years now. I will be converting the PM-25 to CNC immediately. I intend for this thread to be...

www.hobby-machinist.com

Cheers,

John

I will have to finish his thread, since I have started this one I have now decided on the pm30 to get the extra weight and power. Guess I will go with open loop because I will have an abundance of power all away around, planning on 1000-1600oz steppers to mate up with the ball screws(procut kit)

 

[Nrpdyer]

I havent finished my Pm25 cnc build yet but went with closed loop steppers from omc-stepperonline.com. Prices were amazing and shipping was fast. Put everything in the cart to evaluate shipping costs as it will be higher than domestic but still amazing prices for this technology.

 

[Livnpaintball]

Thinking of going with longs motors and drivers but still looking, they have a closed loop set as well. If their warranty process is a pain then I will order from automationtech, or cnc4pc, or similar. Just ordered the pm30 and procut cnc kit.

 

[matthewsx]

Thinking of going with longs motors and drivers but still looking, they have a closed loop set as well. If their warranty process is a pain then I will order from automationtech, or cnc4pc, or similar. Just ordered the pm30 and procut cnc kit.

I'm sure you will be happier going up a size, it's hard to have too much power....

John

 

[Livnpaintball]

Turns out Lngs warranty is a pain in the ass, you have to send them back to China. Stepped online can return to the US location if it ships from there. Stepperonline it is..

 

[shooter123456]

I will have to finish his thread, since I have started this one I have now decided on the pm30 to get the extra weight and power. Guess I will go with open loop because I will have an abundance of power all away around, planning on 1000-1600oz steppers to mate up with the ball screws(procut kit)

One thing to consider is that as the steppers go up in size and torque, their speed gets limited pretty quick. I have a few 400 oz in Nema 23s that I can get to spin at 3000 RPM easily, but a 1200 oz in Nema 34 I have will start to struggle around 1200 RPM. So they will likely have plenty of torque, but it is possible that you will limit yourself on rapids.