My take on a Grizzly G0704 spindle & belt drive

Talking about MY TAKE on a G0704 spindle & belt drive. I mention 2 pole vs 4 pole ..... I incorrectly stated my motor as being a 2 pole... its a 4 pole.
2 pole motor at 60hz = 3600 rpm
4 pole motor at 60hz = 1800 rpm
Check out Sams Channel! - / @cnc4xr7
Sams video... (what I'm referencing in the video)
• PM727M Belt drive Pull...
FULL BUILD OVER ON cnczone.com
www.cnczone.com/forums/benchto...
Instagram @mr_mill_er
#g0704 #thegrizz

[@v9id8eo7]

Excellent conversion Nick, very thorough .. Thanks for the detailed overview of your spindle setup. The 3 pin drive idea is very cool & I can see myself making some mods to my machine to implement that sometime in the future. Gary

[@micholasniller]

Hey Gary! thanks for the kind words.... ill keep ya in the loop as far as how the spindle works. - Nick

[@RustyInventions-wz6ir]

Just found your channel and subscribed. Very nice work

[@Isolerglass]

Nice. Best solution so far!

[@mannycalavera9181]

Brilliant attention to detail.

[@micholasniller]

Thanks Manny. Glad your diggin the build! - Nick

[@SmallShopConcepts]

Nick, Mine is driven with the pulley press fit in the barrel, but I also bored it true while I had it in the lathe to turn the outside and balance it to reduce vibration. My pulley has under 0.0005" runout installed this way. More importantly though check concentricity of your spindle cartridge while secured in the head casting and the upper bearings. Your cartridge bore and cartidge are a very tight fit it appeared. Mine and many others are not and when secured with the set screws this pushes the spindle cartridge out of concentricity with the upper bearings. By driving with the splines and barrel female splines it removes the concerns of this misalignment and doesn't constrain the upper portion of the spindle in a misaligned position.

[@micholasniller]

I figured you wouldn't just shove a round pulley in and unknown bore! lol. How ever one decides to skin their "spindle cat" .... I think we can both agree on the importance of getting as little run-out as possible on all rotating assemblies. - Nick

[@DCT_Aaron_Engineering]

Looking great Nick. If you don't mind me asking, how's the cost going on the build? My conversion cost me around $6K aud back in the day, and I didn't have linear rails or motor upgrade. Cheers, Aaron.

[@micholasniller]

Aaron! No not a problem , I dont have an exact amount (the accountant was fired long ago) the tab all said in done will be easy 7500-8k . That number is highly skewed by the fact that many of the normally "high dollar" or seemingly "expensive" components where either free / on the shelf / "industry friend donations" or made. for the price, the little machine should be pretty awesome. - Nick

[@marmac567]

Have you lost fine Z axis motion??

[@CNC4XR7]

Nick Mine was a D80 frame Lesson IEC motor 2 pole 3425 rpm motor 19mm shaft key way was 6mm I made my pulleys 2 to 1 and 1 to 2 ratio I don't want to over drive if possible tough to say weather to go with a 2 or 4 pole but like you say there cheap motors so I guess will will fined out how both work out.

[@micholasniller]

Is yours a 1.5 hp? I checked the time machine and my key is 19mm as well. As far as what ratio to pick... I really don't know Sam, I figure its relatively easy to make new pulleys for what ever ratio you desire.... figure ill find out some time what works well for my particular machine. For the money, the leasson motors are amazing quality, very cute, and very industrial! what more could one want = ) - Nick

[@CNC4XR7]

I currently have a 1 hp D80 frame but I have a 1.5 hp waiting to go in that I picked up for $75 shipped I could not pass it up.

[@micholasniller]

How could you go wrong for 75$ !!!!

[@skrubol]

If that motor is TEFC (fan cooled,) over or underdriving by much may be a problem. Overdriving more than a little will draw a lot more power into the fan (I think fan power is RPM^2,) and may tear the fan apart if the motor isn't rated for the higher speed. Underdriving more than a little might cause issues with lack of adequate cooling, as I airflow is also RPM^2, and underdriven induction motors producing the same torque produce about the same amount of waste heat. If you really want to be able to vary the speed of the motor, you could take off the fan and mount an external fan, basically converting the motor to TEBC (blower cooled.) Then you could probably go up to 160Hz without much trouble assuming the bearings are the same as the 2-pole version, possibly higher if you research the bearings and have a way to verify the balancing of the rotor.

[@micholasniller]

Hello Jon! thanks for stopping by. I have thought about doing a "TEBC conversion" ... adding a electric fan / removing the plastic fan... on the project list of priorities it currently resides in the "that will make a fun project for later down the road" box. Having run the motor with & without the plastic fan at 120+ hrz , I was surprised by how little vibration the seemingly wobbly fan actually induced... its was for sure quieter though! I'm going to let the motor bearings tell me how they like continual use at 120 hrz , = ) .... when they crap out... replace them. cheers - Nick

[@ikbendusan]

man you turn vocal fry into vocal deep fry (thanks for the videos though lol)