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Larry Gipson
06-17-2015, 4:05 PM
Hi guys,

I have a Grizzly jointer that's a couple years old. Since I bought it, I've wanted to redesign/rebuild the motor mount. The way it came, it's pretty hard to get the belt tension, motor position, motor level, and so forth adjusted all at the same time.

I've been looking at my Jet 15" planer to see how they made these adjustments so easy. On that tool, the motor is mounted on a swinging plate. Since the hinge is mechanically at the correct angle to keep the motor straight, the belt tension a separate adjustment and is mostly provided by the weight of the motor. An additional threaded rod and double nut lets you fine tune the tension and keep it steady. This seems like a better design.

Has anyone done anything like this on the 490x? I really dread belt issues on the machine.

Thanks,
Larry

Jebediah Eckert
06-17-2015, 4:30 PM
I have not but I just set up the same jointer. I also had a tough of a time tensioning the belt, 1/4" deflection, not a chance. In an old thread (I can't find right now) I found a useful tip. The poster made a custom straight edge (with cutouts) to align the pulleys. The poster then used two squeeze clamps he reversed. With the clamps he put one side on the top bar the motor mounts to, and the other side against the roof of the compartment (underside of the bed). He used two clamps, one on both sides of that top bar the motor mounts to. Then you squeeze the clamps forcing the motor lower, giving you more tension. Doing this I was able to get down to about 1/4" of deflection. This method was also easy to keep the pulleys in line and the motor level. You just squeeze a touch harder on one clamp to adjust. When it's where you want, tighten the 4 bolts and remove the clamps. In the same post he also wedged a board from the top center of the motor to the top of the jointer, the theory being it stays secure longer. I also did that. Because I did it all at once I'm not sure what difference it made, but it was worth a try.

This process took me about 10 minutes tops once the panels are open. The jointer runs a ton better, way less belt slap, and I can balance a nickel on edge when off, start, run, then shutdown, nickel still stands.

I wish I could find the post. If this doesn't make sense PM me, it's easy.

Larry Gipson
06-18-2015, 3:55 PM
I have not but I just set up the same jointer. I also had a tough of a time tensioning the belt, 1/4" deflection, not a chance. In an old thread (I can't find right now) I found a useful tip. The poster made a custom straight edge (with cutouts) to align the pulleys. The poster then used two squeeze clamps he reversed. With the clamps he put one side on the top bar the motor mounts to, and the other side against the roof of the compartment (underside of the bed). He used two clamps, one on both sides of that top bar the motor mounts to. Then you squeeze the clamps forcing the motor lower, giving you more tension. Doing this I was able to get down to about 1/4" of deflection. This method was also easy to keep the pulleys in line and the motor level. You just squeeze a touch harder on one clamp to adjust. When it's where you want, tighten the 4 bolts and remove the clamps. In the same post he also wedged a board from the top center of the motor to the top of the jointer, the theory being it stays secure longer. I also did that. Because I did it all at once I'm not sure what difference it made, but it was worth a try.

This process took me about 10 minutes tops once the panels are open. The jointer runs a ton better, way less belt slap, and I can balance a nickel on edge when off, start, run, then shutdown, nickel still stands.

I wish I could find the post. If this doesn't make sense PM me, it's easy.

I remember the post you refer to and set the thing up that way the last time I fooled with it - thanks(!).

About a year after I set it up the first time, the little set screws worked loose on the motor pulley and damaged what it could. I replaced the belt and pulley at that time, then found some capstan screws to replace the set screws. I could put more torque on that style screw. I also put a little loctite on them. It's been ok since. I'm going to have to clean the head one of these days, so I'll be into the thing again. I'm looking around for some thick walled tubing with 1/2" ID and about 12" of 1/2" rod so I can make a long hinge. If I can find that, I can weld the hinge on a sheet steel plate and make a motor mount similar to other equipment I have. If I'm going to keep this thing, I'm going to make it easier to keep the belt tension right. Ii have a mig welder and a plasma cutter. Might as well use them :)

glenn bradley
06-18-2015, 4:39 PM
Has anyone done anything like this on the 490x? I really dread belt issues on the machine.

Thanks,
Larry

Have you had belt issues? Does yours have the new ribbed (serpentine?) belt or the standard v-belt? Mine has been trouble free since first installed and adjusted in 2008 but, I did put a link belt on it right off.

Ken Fitzgerald
06-18-2015, 6:02 PM
I haven't had any belt issues on mine.

That being said, I didn't have any difficulties tightening mine several years ago.

Larry Gipson
06-20-2015, 8:57 PM
Have you had belt issues? Does yours have the new ribbed (serpentine?) belt or the standard v-belt? Mine has been trouble free since first installed and adjusted in 2008 but, I did put a link belt on it right off.

The belt isn't the issue. It's the new ribbed belt. The problem I seem to be having is getting enough tension on the belt. Also keeping the pulley tight enough. I checked it today and things have slipped. I can tell by the noise it makes.

Terry Beadle
06-24-2015, 2:18 PM
You also might try the automotive world's belt spray that helps the belt last longer and aids to the grip.

Larry Gipson
11-16-2015, 2:15 PM
I should probably update this. I finished the mod on my 490x shortly after I wrote this initial inquiry.

There were 2 separate issues I've solved. First, it was too hard to adjust belt tension. This was solved by welding up a large hinge. The motor sits on the hinge, and a bolt pulls down the hinge to tension the belt. This separates motor and belt alignment from the tensioning process - which is really easy now. It adjusts with a wrench. Btw, I thought of an easier way to do the same thing instead of making the hinge, but naturally I had the hinge made when I thought of it. :)

The second issue I had was with the aluminum (bottom) pulley. The screws always loosened. I have had 3 aluminum factory pulleys now; two have been on the machine, and both loosened. The best advice from Griz was to use 2 shorter set screws. The first is supposed to tighten while the second holds. I suppose this is sort of the ultimate locktite. Since I couldn't find screws short enough to work with the key, I went another direction. Incidentally, the set screws are not machined in the aluminum pulley at 90 degrees to the shaft. The angle might be enough to allow them to loosen (speculation only). Also, the first 2 pulleys inside diameter was loose on the 0.75" motor shaft while the 3rd pulley won't go on at all. This last one might go on if it was heated - if not it would have to be enlarged slightly. Perhaps the tightness of the fit might have helped the set screws by making them not have to work so hard. In any case, I did something different. Griz still sells a set of steel pulleys and a 1/2" v-belt that can be retrofitted to the machine. The issue there is that the pulleys I received were 7/16" and not 1/2" so a 1/2" belt would sit proud of the pulley when mounted. The bottom pulley still had 2 set screws, so I bought a 5"dia 2 part pulley to replace it. This pulley system uses a tapered collar that mounts on the shaft. The outer pulley has a larger tapered hole in it. As you tighten a couple of 1/4-20 bolts, the tapers pull together, solidly grasping the shaft from all directions. (No set screws.) I used the Griz steel top pulley and a HF link belt. The pulleys don't slip and the link belt is quieter than the original belt. The 490x has been working quite well with this arrangement.

glenn bradley
11-16-2015, 2:23 PM
Thanks for the update Larry. Sounds like you've got it all dialed in now.

Larry Gipson
11-16-2015, 2:39 PM
325384

I suppose a picture would help. All mods are bolt-on so the machine can easily go back to factory spec if desired.

The bottom pulley consists of these 2 pieces:

TB Woods Type QT QT34 Sure-Grip Bushing, Steel, Inch, 0.75" Bore, 1.625" OD, 1.25"
TB Woods BK52 FHP QT Bushed, 4.95" Outside Body Diameter V-Belt Sheave

David Masters
11-23-2015, 1:22 AM
This is very helpful. I've ruined one pulley and belt, and find I need to check and tighten the set screws regularly to avoid the problem from happening again. Belt tension adjustments are a real chore. If you have the time, could you post a larger picture? I'm having trouble seeing what you did. Thanks!

Bill Space
11-23-2015, 5:04 PM
Hi all,

Hopefully the following which included images will show up in this post.

A while back I made a modification to my G0490X To make belt tensioning easy. I cut and pasted the following from a thread I started which got off track...

I made simple brackets which on the pulley side of the motor provide down pressure for belt tightening, and on the fan side of the motor hold it in an adjustable position. When making adjustments to the motor position (angular and horizontal position, all four motor mounting rail bolts need to be loose. The belt holds the pulley end of the motor, but the fan end wants to fall unless supported by something. I initially used a bottle jack to do this but found it cumbersome. I was not able to easily adjust the belt tension so I came up with this idea. Works really well!

Here goes my attempt to attach pictures. I hope the pictures will be clear enough. I did add some notes to them...

Oh, almost forgot. How do you guys align your pulleys? I made a simple tool that worked well for me. I checked the flatness of the edge that contacts the pulleys, using the jointer table, then cut a slot in the melamine covered particle board so it could slip over the edge of the motor base...

Again I hope the photos come across in this post because I do not know where I might find the originals...


Billhttp://www.sawmillcreek.org/attachment.php?attachmentid=251149&d=1358209332&thumb=1 (http://www.sawmillcreek.org/attachment.php?attachmentid=251149&d=1358209332)http://www.sawmillcreek.org/attachment.php?attachmentid=251150&d=1358209333&thumb=1 (http://www.sawmillcreek.org/attachment.php?attachmentid=251150&d=1358209333)http://www.sawmillcreek.org/attachment.php?attachmentid=251151&d=1358209335&thumb=1 (http://www.sawmillcreek.org/attachment.php?attachmentid=251151&d=1358209335)



Too much to do...Not enough time...So I am just going to do what I feel like...

Larry Gipson
11-24-2015, 2:22 AM
Bill, that's pretty close to what I thought I might do when it was too late to do it :) I had the hinge made. I thought about installing 2 L brackets, one on each end of the top brace on the rear side. You could then use threaded rod (home depot?) to a lower brace and then use a couple of nuts to adjust the belt. It isn't as perfect as the hinge though as you still tilt the motor during adjustment. Your solution is a good one though. Better than what Griz did.

I like your hinge alignment tool. Of course, I used v-belt pulleys instead of the aluminum ones that came with the machine. I could just use a piece of masonry string with a nut tied on it to check alignment. Yours is better :)

I'd use the ribbed belt if I could find a matching sheave that would work with the QT34 bushing. If anyone ever stumbles onto such a thing, let me know.

Larry Gipson
11-24-2015, 2:35 AM
David, pm me and I'll send you a larger picture if you like. The one I posted can be zoomed in on (right click; open in new tab; ctrl + )

This is just a large hinge made from 1/4" plate steel I had on hand. I bought 1/2" id tubing with a 1/8" wall, oversized a few thousandths so a half inch bolt could be used as a hinge pin. The short side of the hinge goes between the two horizontal struts. The motor sits on the long side of the hinge. This side has a square cutout so the pull down bolt can attach easily. There's 1x2 in tubing with 1/8" walls I had on hand that I used for the lower horizontal strut. I welded a couple of tabs on it so I could mount a horizontal bolt. There's a piece of that 1/2" id round tubing welded on another bolt that makes the pull down. The motor is as close to the hinge point as possible, but spacers were still needed to align the belt correctly (vertical axis). I think I used a 1" square aluminum bar (1ft long) on each side to shift the hinge to the right. Pretty much it.