Router seems slow, any suggestions?

[Hack]

I am curently in the process of building a 32 x 48 x 6" moving gantry router and just got the lead screw hooked up tonight on the x axis. Just for grins I used my cordless drill to turn the screw just to see the axis move. My lead screw is simple 1/4 x 20 threaded rod. My question is this:

While my drill is only turning at say 700 rpm and makes the axis move slowly, how many rpms does a stepper motor turn? Will I see some faster speeds or should I look at a different lead screw?

Thanks

[balsaman]

What drive will you use? With steppers you will be doing well to get 700 rpm. Generally one problem with a machine that large is the time it takes to move from extreme to extreme without spending a fortune on the drive system. Speed costs money.

A coarser leadscrew may get you a bit more speed but you get less "push". I used 1/2"-10 acme screw with 100 oz motors and was getting 30-40" per minute using a 30 volt supply.

Don't worry too much about speed for now. Get the thing going.

Eric

[samualt]

Perhaps you should move to servo motors. Mine are rated at 2000 rpm at 60 volts, which is what i will be supplying them. In fact, I've had a devil of a time slowing them down with pulleys.

[arvidb]

First step would be change to ACME screws. If you go to 5 TPI with good quality ACME screws, you get 4 times the speed you get with your 20 TPI screws, but should still get about the same force (or "push") as with the allthread, because of the better efficiency of the ACME.

Arvid

[balsaman]

We need to know what motors and driver you are using.

Eric

[Hack]

Well folks, at this point I have not purchased the driver or motors yet, but was heavily leaning towards the FET3 / Cruiserweight System sold by stepperworld. This chice was based mainly on th fact that it is quite complete and with my limited knowledge of the electronics aspect, this seems like the best chice for me? I have heard good things about the xylotex products, but have not seen as complete of a package listed on their website.

Do you folks have any other suggestions?

Thanks

[balsaman]

Well,

That system is not known for it's speed. Count on 15" per minute on 1/2-10 acme screws.

I would recommend HobbyCNC's new chopper board and some of thier 80 oz motors on 24 volts, even if you have to pay someone to assemble it for you. Much faster. More efficient too.

Eric

[Hack]

I am planning on using a PC laminate trimmer for my spindle. Will an 80 oz motor be strong enough to power the z axis?

[CNC Darren]

I am using the 3axis chopper drive combo from hobbycnc along with the 80oz/in motors and it has no problems with a Ryobi trim/laminate router as far as I can tell. I am running 3/8-16 threaded rod for lead screws so yours would actually have a better mechanical advantage over mine but would be a bit slower. I'm running a 25/40 volt regulated power supply on it right now with 25v, had a 12 volt on it and it can run much faster than before on the 12. I havent tried the 40v yet but the board should take it just fine as its rated to 44v.
CNC Darren

[BigDaddyG]

Hello,
You shoud check out Automation Direct. They just came out with a new line of motor, power supply and drivers and 20 feet of wire. All brand new stuff, delivered to your door in two days or so and all configured together. I just got mine in for a lathe I build and it sure looks promissing. 32v @4amp power supply $99. The driver boards are $149 (1/2, 1/5, 1/10 and 1/50 step modes) and 276oz motors are $39, 434oz motors are $99 add $9 for 20' of cable. Like I said, they are priced correctly and they also carry a great line of sensors/switches for your machine, oh yeah and enclosures. Now if they only get into the servo market I will be happy.

Like I said, I have been buying from them for years and am very pleased with everything I get from them, the prices you just cant beat and very use friendly web site.
Good Luck,
Glen

[Hack]

I guess that my biggest concern here is that I want to ensure that the components are matched properly so that I don't screw up the selection process. Also, if i end up building machine #2 so to speak, I would probably want to transfer the electronics from this machine to the next.

I really do not expect blazing speed from this machine, but would like to know that if I need it to go faster, I simply just need to replace the allthread with an acme leadscrew or something.

I like the prices of the items at Automation Direct, but are these reputable products and match well together? I have heard good things about the xylotex stuff like I mentioned before. Do they offer a complete kit that will work? Looking for steppers, controller, power supply.

Thanks all, and pardon my ignorance.

[BigDaddyG]

Hello,
Yes, Automation Direct is a very well respected company. I have been dealing with them for years and never a complaint. They are located in the Atlanta area (I am in Sunny Fla), I get my stuff in a day or so, always as expected.

You migth want to look at Nook for your lead screws. MSC is where I go to get them but they offer a Precision Lead (+/-.003) with anti-backlash nuts at a very reasonable price. Somewhere inbetween lead and ball screws in price, but good precision for the buck.

Again, Good Luck,
Glen