Page 5 of 13
Posted: Sun Sep 05, 2010 12:07 pm
by JPG
Perhaps one of you sacrif---early birds will be so kind as to measure the od of the three pulleys: Motor, idler shaft(I assume both are equal) and the main shaft.
I am curious if they retained the 1.6:1 ratio between the idler and main shafts.
Posted: Sun Sep 05, 2010 12:33 pm
by jayhawk
Motor pulley: 3.17 inches, Idler pulley 1.17 inches, Drive sleeve pulley 1.9 inches
1.9 / 1.17 = 1.62
Posted: Sun Sep 05, 2010 3:41 pm
by JPG
jayhawk wrote:Motor pulley: 3.17 inches, Idler pulley 1.17 inches, Drive sleeve pulley 1.9 inches
1.9 / 1.17 = 1.62
Thank You!!!!!!!:):):):)
Posted: Mon Sep 06, 2010 8:31 am
by nuhobby
JPG40504 wrote:This is something I have wondered about. I assume the eccentric sleeve has been deleted. (not sure about that!)
Since the shaft separation between the main and idler shaft is fixed, how is top belt tension adjusted. I assume the motor is adjustable relative the the idler shaft.
Whole lotta assuming there! What is reality?????
The Power Pro Installation kit includes both a bound Manual (with instructions) and a DVD guide. The DVD is quite thorough -- and much longer than the one on the web-site:
http://www.shopsmith.com/shopsmithpowerpro/pp_diy.htm
The DVR-motor is a massive object, and Shopsmith has provided some additional heavy extrusion pieces on the sides that interface between the motor and the headstock metal. These provide set-screws and lock-screws at the four corners of the motor. So it's posible to fine-tune the distance between motor-shaft and idler-shaft. With this adjustment, and the idler-eccentric adjustment, both belts can be optimized for sufficient tension as well as minimizing the (summed) cantilever-forces on the idler-shaft.
The DVD is also helpful for providing references on what the working unit should sound like. The DVR motor is a lot quieter than the induction motors, but not whisper quiet. At very slow speeds it has a sort of a 'growl' sound, and sometimes you can sort of sense the servo-actions going on to keep the speed constant. It's enough quieter compared to the original motor that you can notice remaining sounds that may have been masked before, from the quill area, etc.
The claim about eliminating startup brown-outs is 100% true! And you really get the sense that you're only using enough electricity to do the exact job at hand; no excess power. There is not much obvious air-flow going on, and it probably doesn't need a lot of airflow anyway.
I'm now on a conventional grounded outlet (no GFCI) and everything is fine. Looking forward to a real wood project, hopefully soon.
Posted: Mon Sep 06, 2010 10:18 am
by JPG
Hooraah!!!!!
Thought the link below IS appropriate to THIS thread!;)
https://forum.shopsmith.com/viewtopic.php?p=74255&postcount=4
Posted: Mon Sep 06, 2010 11:03 am
by jayhawk
My holiday guests left late yesterday afternoon so I got busy in the shop last night and got the PowerPro upgrade installed. I installed mine in a "C" headstock casting. The instructions were clear for the most part but they didn't specify which groove the upper belt should track in on the drive sleeve pulley. I moved the belt left and right a groove at a time and finally felt it was tracking true with 2 grooves showing on the left and three on the right when viewing from the power switch side. The belt tension adjustment was easy but may take a while to tune my ear to the noises the new motor makes. Basically, you run the motor at 3450 RPM and listen to the sounds it makes as you slowly move the eccentric CW and CCW. You stop where it is the quietest. I checked the tension on the belts after the adjustment and they are both very taut. I'm sure I have it adusted correctly but I may go through the process again later. After the belt adjustment I ran through the lower speed ranges a couple of times then got brave and ramped it up to full speed. It got up to speed fast and was really pretty quiet considering the covers were still off and it was spinning at 10000 RPM! I found when I shut down from this high speed run that both the output shafts on the left side were noticeably hot. This may be because the belts and bearings were new and tight. It should be fairly rare that I operate at high speed. I put the covers on and mounted a sanding disc with 80 grit paper for a test run. It ramped up to 1350 RPM quickly and after gently sanding a 2x4, I kept an eye on the RPMs as I put a good amount of pressure on the disc with the wood. It got a little noisy from the sanding and from the motor ramping up but the speed remained stable. I plan on doing some sawing today and will try the same type test. I was hoping that my Lift-Assist would raise the new headstock as usual but it didn't, so I will have to spring for the stronger strut. I ran mine on a 120 VAC, 20A circuit with a GFI breaker with no issues. Overall, I am very pleased with this upgrade.
Posted: Mon Sep 06, 2010 11:19 am
by JPG
jayhawk wrote: . . . The instructions were clear for the most part but they didn't specify which groove the upper belt should track in on the drive sleeve pulley.
Now why does this sound familiar???:rolleyes: . . . The belt tension adjustment was easy but may take a while to tune my ear to the noises the new motor makes. Basically, you run the motor at 3450 RPM and listen to the sounds it makes as you slowly move the eccentric CW and CCW. You stop where it is the quietest.
This appears to balance the tension between the two belts - Is not the motor to idler distance also adjustable??????
. . .
Just trying to fully understand!
Posted: Mon Sep 06, 2010 11:28 am
by jayhawk
Both belts run on the idler pulley so as the eccentric moves up or down, one belt gets tighter, the other looser. That's why you shoot for the middle ground on the noise level. The motor looks like it is mounted rock solid to me and not adjustable.
Posted: Mon Sep 06, 2010 11:53 am
by JPG
jayhawk wrote:Both belts run on the idler pulley so as the eccentric moves up or down, one belt gets tighter, the other looser. That's why you shoot for the middle ground on the noise level. The motor looks like it is mounted rock solid to me and not adjustable.
Your turn NuHobby!

:)
Posted: Mon Sep 06, 2010 1:28 pm
by nuhobby
The part about adjusting the motor mounts, I could see in the DVD, but not in the written instructions book. In the DVD, Jim McCann notes that the motor-mounts are pre-aligned closely at Shopsmith, and you can't adjust them very much from that point. In my case I made a minor adjustment not so much to change belt tension, but to get the motor exactly level -- compensating for slight drilling tolerances when I bored the headstock. That made things overall better for me.
This AM I ran a few pieces of hard 1-1/4" thick southern yellow pine on the PowerPro table-saw mode. Wow! The DVR motor really shines in that mode. You can shut it down and re-power the blade very often. The motor keeps the blade going the right speed even in a heavy rip. Vibration is almost non-existent, even when ramping up the blade speed.