A Project Quest

Jim, I shouldl have something to show you on that in a week or so. The students at the Trade School where I mentor are working on it in the Lab. Wish them luck please as they work very hard on these things. Sometimes they get it right, sometimes not at all. They jumped at the chance.

Fat fingers Toolmaster. LOL Happens all the time.

"Bill"
 
Last edited by a moderator:
JimDawson said:
I finally had a chance to play with a cheap stepper speed controller, without some additional electronics it won't make a good table drive. I could not get it to accel and decel at the ends of travel, so it won't generate a trapezoidal motion profile. The least cost method to properly drive the table with a stepper motor is to hook a computer to it and run Mach3 on the computer. CNC surface grinder here we come..:grin:
Click to expand...
An Arduino can control a stepper and provide all the ramps and stuff you could want.
 
I haven't checked in with the students in a few days. I mentor tomorrow. I believe they are going with the Arduino unit. Not positive though. I will know more tomorrow.

"Bill"
 
I machined the 3 IPF tapers today on my mockup, arbor, my machining arbor , and my balancing arbor.
image.jpeg
This is the completed balancing system. The arbor is as close to perfect balance as it gets. I can set it on the stand in any position and it does not roll. I put the mock up wheel arbor on it and it rocks slightly and rests heavy side down, but the balance on the mock up is very close.

image.jpeg
This is the mock up arbor and the balance arbor and the machining arbor. The tapers came out great. I am very pleased with them so far. Next...... Machine the mockup arbor and check the balance.
 
Nice work Mark, may I ask what steel you chose? I think 12l14 would be good for the taper because if the arbor spins the lead in the material could possibly help prevent galling.
 
  • Like
Reactions: ome
Andre said:
Nice work Mark, may I ask what steel you chose? I think 12l14 would be good for the taper because if the arbor spins the lead in the material could possibly help prevent galling.
Click to expand...
I was highly considering 12L14 but in a 3" diameter it is very expensive. I went to my only local supplier ( aka. "Junk yard") and he had some mystery metal 3 1/16" diameter. He said it was an "unknown alloy " to him so he sold it to me for $12 a foot. It cuts like 12L14. I don't know what it is but it machines great. I am using it to make the arbor.
 
In working on the grinding wheel arbor, I mounted it on the special arbor I made to machine the wheel arbor and turned all surfaces to finish size so everything is concentric with and located off the taper.
image.jpeg The machining arbor is held in my ER 40 collet on one end and a center on the other end. I measure .0001" run out. I can live with that. By using this setup, I can turn the part around and it stays true.
image.jpeg
image.jpeg
All the surfaces are turned to finish size and polished. There is a relief to the inside for clearance. The shell will be gripped by the outer surface of the arbor.
image.jpeg The rear is turned to finish size leaving a .125" wall thickness on the recess. This recess covers the end of the spindle to keep debris and grit away from the spindle front.
image.jpeg The arbor is threaded 1 1/4"-16 left hand threads. There is a .250" wide register that supports and locates the grinding wheel.
image.jpeg The inside of the front portion of the arbor is threaded .984-16 right hand threads. This is for screwing in the puller to remove the arbor from the spindle.
image.jpeg I am now working on the nut that holds the grinding wheel on the arbor. It has a recess matching that of the arbor for clamping the wheel. There will be a thin ground steel flat washer that goes between the grinding wheel and the nut. ( I'm working on that). This arbor should be done this week and so far it seems good.
 
You must log in or register to reply here.
Back
Top