Hi Folks,
I am currently building a modified version of JGRO's machine (build log is here...
http://cnczone.com/forums/showthread.php?t=6244) and I have hit a major stumbling block!
I originally bought a Stepperworld SP-3/HT card and three Nema 23 steppers rated at 5V, 1A, 53 oz./in. torque which I am running from a regular computer power supply. When I bought the card I was undecided between the above and the Hobby CNC kit and finally went for the SP-3/HT based on it's alleged 'high torque' output. Unfortunately due to a combination of the card, power supply and the TPI of my leadscrews (1/4"-20 all-thread) I find that my machine speed is woefully below what I expected or need as I will mostly be cutting wood and plastics. Using Turbo CNC as the control software the best I can get is 3.75" IPM in rapid before the motors start to lose steps big time! The motors just stall once you hit the 3.75" limit. I have tried the card in both 'high torque' and 'half-step' modes with very little difference in performance. I have checked and re-checked the rails/slides to make sure they are not binding and they run nice and smooth in all directions with very little effort.
I obviously need to upgrade the control/motor/powersupply set up but the big question is just which way do I go now? I am medically disabled and on a very fixed income so every cent counts when it comes to expenses but having come this far I really need to get this machine working.....lol.
The Hobby CNC package has been recommended to me by Balsaman (from here) and others on the TCNC Yahoo group and as I said it was on the top of my list before (along with the SP-3/HT package). The problem I now face is just what do I do? Buy just the board and hope the motors and power supply I have are up to the job? Buy the board and the power supply and hope my motors can cope with the increase in voltage/speed? Go the whole hog and buy the complete package with the larger motors and power supply and sell what I have?
The only other solution I can think of is to change out the 1/4"-20 all-thread for something with a coarser pitch but that would be a major re-engineering challenge at this stage as the machine parts are glued and screwed together and would have to be re-machined to accept larger diameter leadscrews. I would also have to re-make my A-B nuts from scratch too.
Do you guys/gals have any suggestions as to my best options from here?
Thanks for your time.
Larry