Am I at the limits of what I built?

[WoodSpinner]

Hi, I'm new to the cnc hobby and have built a mcwire controller and am using Nema 17 motors with 5/16-18tpi threaded rod. My table is a mobile table design with a 12x14 work area. My router is a rotozip that runs at 30k rpm.

I realize there are a lot of limits to what I built, but its been fun so far. I manage about 20ipm but experience a few lost steps at that speed so I dialed it down to 15 and its been very accurate so far.

A simple table smoothing routine using a 3/4" mortising bit runs over an hour at present and the womem in my life wont put up with 8 hour runs to make signs(my last one ran that long) and even tho I got 150 bucks for the sign they seem to care more about the noise.

I've been looking at bigger/faster motors in the hopes that would speed things up a bit. I've about decided to get some Vexta PK268-03A if I can ever afford them but that will be a while.

I looked at that chinese controler on ebay but the reports on it dont make me eager to spend the money, it seems that even with the fix their still funky.
so I guess I'll eventually get some geckos(when I hit the lotto).

I'm wondering if there is something I can do short of spending tons of money to speed things up, I've considered feed screws with less tpi but my little motors dont have a tons of power and I'm afraid it will just be a waste of energy.

Any and all suggestions would be appreciated.

John

[DeadTom]

John,
Put your existing working machine in a sound proofed housing.
Or in other words put your tool in a box to quiet it down.
But if you have to build a bigger/faster machine then that is what you will need to do.
DT

[ger21]

The easiest way to make it quieter is to get rid of the Rotozip. Get a variable speed laminate trimmer or Bosch Colt. At their lower speeds, they're much quieter.
You don't need 30,000 rpm, especially at your slow speeds.

Seems like your on a budget, so here's what I'd recommend. A hobby CNC drive, for under $100. Skip the Vexta's, they're more expensive. Go with Chinese motors from www.kelinginc.net

Get rid of the 5/16-18 screws. Go with acme, 10 turns per inch or less. 3/8-10, 3/8-8 2 start, or even 1/2-10. This will get you at least 100ipm. The 2 start would probably get you close to 200ipm.

Of course, speed costs money.

[WoodSpinner]

Originally Posted by DeadTom John, Put your existing working machine in a sound proofed housing. Or in other words put your tool in a box to quiet it down. But if you have to build a bigger/faster machine then that is what you will need to do. DT

Interesting idea, its certainly something to consider.
thanks

Originally Posted by ger21 The easiest way to make it quieter is to get rid of the Rotozip. Get a variable speed laminate trimmer or Bosch Colt. At their lower speeds, they're much quieter. You don't need 30,000 rpm, especially at your slow speeds. Seems like your on a budget, so here's what I'd recommend. A hobby CNC drive, for under $100. Skip the Vexta's, they're more expensive. Go with Chinese motors from www.kelinginc.net Get rid of the 5/16-18 screws. Go with acme, 10 turns per inch or less. 3/8-10, 3/8-8 2 start, or even 1/2-10. This will get you at least 100ipm. The 2 start would probably get you close to 200ipm. Of course, speed costs money.

As money becomes available, I will probably go that route, change the router, controller board and motors, but I may end up building a box to put it in first tho, fixed income and all

Thanks again for the suggestions.

John

[WoodSpinner]

Originally Posted by WoodSpinner Interesting idea, its certainly something to consider. thanks As money becomes available, I will probably go that route, change the router, controller board and motors, but I may end up building a box to put it in first tho, fixed income and all Thanks again for the suggestions. John

Well, Money came available for a new controller, so I purchased the 4 axis HobbyCNC pro chopper board. All i can say is I am in love with it. My fast jog speed is now 120ipm, with cutting at 60ipm, motors run much hotter, but only going to 43c so not a concern......

I set it to run at 1/2 step and its running silky smooth, what benefit would I gain from trying 1/4 step or higher?

John

[hemsworthlad]

Smoother running motors and possibly smoother action due to smaller steps per rev but mainly smoother motors.
Will be more taxing on PC and parallel port due to higher steps per needed in Mach(If using Mach), you may need to up the kernal speed to get same speeds if using higher micro steps.

[WoodSpinner]

I am now at a point where I want to start buying bigger/stronger motors for my machine, also for my next machine.

My power supply is at present putting out 34 volts at 10 amps. and given the hobby cnc pro driver, my max would be 40v I believe.

I'm wondering if this motor would be a good match for my driver, or would someone suggest something as a better match.
Vexta PK268-03A (Oriental Motor Company).
Any help would be appreciated.

John