Jeff-C175 7,202 #76 Posted July 8, 2022 (edited) 4 hours ago, Horse Newbie said: Bermuda Definitely not that... It's got a sort of 'fuzzy' head, but it's not like any of the other 'fuzzy head' pictures I've looked at on the web. I went out and looked and there are no seed heads, as I recall those come later in the season on this grass. @8ntruck I messed around with the deck for a few hours trying to determine why it's having issues staying erect. I think my deck might need some 'enhancers'. The bushings and such on the lift arm are not terribly worn, and taking a good look at it I can see that it's not bent. I suspect that all of the arms either hit, or come very close to the steering support. The latching mechanism seems to show some wear and this may be the main issue. This slot is somewhat rounded over. Also, there is wear on the 'mating edge' of the 'push rod'. It also appears to be bent down just a little. If taking it apart wasn't such a chore I would bend that rod up about an eighth of an inch. However... no matter what I adjust, I can not make this so... the rubber bumpers will NOT contact the foot rests. Ain't gonna happen. The only way this MIGHT happen is if the lift arm did not hit the steering support. I MIGHT take the deck off and raise the machine and take a closer look... but there's other projects I need to attend to at this time so it will be a while. Looking at the diagram I just noticed something though... the trunion is in the MIDDLE hole and this says it should be in the rear most hole. I wonder if this would give a little more room for the rod to drop into the slot before the lift arm hits the steering support? Going out to try that now... OK... made no difference, didn't expect it would. Had to tighten up the adjustment to get it back to where it was ... as high as it could go before hitting the steering support. It DOES lift a bit easier though, better leverage. So apparently there's nothing I can do for this condition other than major surgery which I'm not inclined to perform, so I'm just going to have to live with it. I am going to pull the blades and rebalance because that WOO WOO WOO just ain't right... and very annoying! Edited July 8, 2022 by Jeff-C175 1 Share this post Link to post Share on other sites
8ntruck 7,016 #77 Posted July 9, 2022 On my lift lever latch, I am suspecting that there is done wear that is the cause of the problem. I have not investigated that, though. Your WOO WOO WOO is probably a beat frequency caused by two things vibrating at slightly different frequencies. The noise is the two things going into and out of phase with each other. Going back to blade balance is a good place to start. Swapping the blades to different spindles may help. Are all of the bearing housings firmly bolted to the deck? Are the lift fins on all of the blades the same? If you have one that is different, that might be the cause. Try watching the deck belt tensioner spring. See if there is a visible vibration in it that is in time with the noise. If there is, a different spring might be a solution. These are just brainstorming ideas. No idea if they will help or not. Good luck. 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #78 Posted July 9, 2022 (edited) 33 minutes ago, 8ntruck said: beat frequency Very familiar with the phenomenon, know exactly what you mean. Yep, everything is tight. Spindle bearings in great shape. Blades are a 'set' of Toro OEM blades that have only been sharpened maybe twice. Problem is that the person who sharpened them had no idea what they were doing and I had to remove a fair amount of material in order to get the correct angle on the edges. I did the 'nail in the wall' balance on them as I've done many times before, but I'm not confident that I was careful enough. Pretty much the only thing it can be is the individual blade balance. I'll be removing them to check the balance in the next few days or so. I don't know if it makes any difference if the blades all weigh the same but I'm going to check that also just for ha-ha's. Edited July 9, 2022 by Jeff-C175 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #79 Posted July 9, 2022 (edited) 19 hours ago, Jeff-C175 said: Pretty much the only thing it can be is the individual blade balance Took the blades off again and they are as balanced as can be. I didn't trust the 'nail in the wall' even though it has always worked just fine for me so I pulled some old front wheel bearings outta the scrap bin and found a piece of 3/4" shafting. Clamped the bearings and the shaft in the bench vice, made sure the shaft turned smoothly, slid the blade onto the shaft and it stayed everywhere I pushed it so it appeared to be in balance. I then took some small magnets and unbalanced the blade with them and sure enough, the end with the magnet goes down as it should / would. So I trust that this makeshift balancer is accurate. And if anyone is curious about the individual weights, they are as close in weight as my fish scale will measure. Probably +/- an ounce or so. So now I'm back to having no idea at all what that WOOOO WOOOO WOOOO harmonic vibration is all about! Edited July 9, 2022 by Jeff-C175 1 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #80 Posted July 9, 2022 Looks like I might have bought the wrong blades! This is what it says on the box! 1 1 Share this post Link to post Share on other sites
8ntruck 7,016 #81 Posted July 10, 2022 Think maybe you got a dynamic balance problem? One of the blades is not quite straight? All of the spindle shafts straight? The blades tighten up square to all of the shafts? 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #82 Posted July 10, 2022 41 minutes ago, 8ntruck said: Think maybe you got a dynamic balance problem? One of the blades is not quite straight? All of the spindle shafts straight? The blades tighten up square to all of the shafts? I've been running all those thoughts through my head... Checked the straightness of the blades, and the spindles when I had them apart, all good. Wire brushed the seating surface of the spindles, thick washers, and the nuts, and the thin washers are new, so I'm confident the blades are seated. They were torqued to100 ft/lbs. Something Snoop-Don said keeps making noise in my head... "Loosen the blades and tighten again..." or something to that effect. The hole in the blade IS just a tad smaller than the spindle shafts. When I remount them I'm going to try to get them centered and see if that helps. The only thing left is the belts and they are nearly new, probably only one cutting season on them. 2 Share this post Link to post Share on other sites
Jeff-C175 7,202 #83 Posted July 10, 2022 I just measured the 'play' of the blade on the spindle. Looks like it's about 40 thou or so. Probably enough to cause a 'slight' disturbance I think... If I'm able to get them centered and tightened without moving them while doing so, we'll see when I put it back together. 1 Share this post Link to post Share on other sites
Jeff-C175 7,202 #84 Posted July 11, 2022 I borrowed my neighbors blade balancer today and one of the blades was just a little off. Other two were fine. Will remount the deck tomorrow and see... 2 Share this post Link to post Share on other sites
Horse Newbie 7,072 #85 Posted July 11, 2022 (edited) 19 hours ago, Jeff-C175 said: I just measured the 'play' of the blade on the spindle. Looks like it's about 40 thou or so. Probably enough to cause a 'slight' disturbance I think... If I'm able to get them centered and tightened without moving them while doing so, we'll see when I put it back together. 8 hours ago, Jeff-C175 said: I borrowed my neighbors blade balancer today and one of the blades was just a little off. Other two were fine. Will remount the deck tomorrow and see... Here’s my thoughts… some of you may say “ If you don’t have a solution, keep it to yourself “. If the blade mounting holes are that critical, and I know they are, to a certain extent. ( as far as the blade fitting the spindle shaft tightly ), seems like they would fit more snugly, but then as far as I’ve read, this isn’t a very common problem. So maybe a blade spinning 40 thou off center isn’t enough to cause the Woo, Woo. And balance… I try to get my blades as close to perfect on balance as possible, but I’m sure they have never been perfect after I have sharpened them. Now keep in mind that I have not as yet used my 48 inch SD Wheel Horse deck. (See first paragraph again) But I’m certain that an unbalanced blade would probably react the same on a different brand name deck. The blade balancers I use are the hang it on a nail method and the cone shaped thing on a point. @Jeff-C175 , what kind of blade balancer did your friend let you borrow ? Edited July 11, 2022 by Horse Newbie Share this post Link to post Share on other sites
Jeff-C175 7,202 #86 Posted July 11, 2022 3 hours ago, Horse Newbie said: what kind of blade balancer It was the cone shaped thingy. Was actually a little more accurate than that thing I rube goldberg'ed up with old wheel bearings. It just wasn't sensitive enough to show this small imbalance. I'll know in a few hours! 1 Share this post Link to post Share on other sites
Handy Don 12,234 #87 Posted July 11, 2022 27 minutes ago, Jeff-C175 said: It was the cone shaped thingy. Was actually a little more accurate than that thing I rube goldberg'ed up with old wheel bearings. It just wasn't sensitive enough to show this small imbalance. I'll know in a few hours! Reading through this thread I keep coming back to the harmonics. The cyclic resonance/dissonance has to be from two things rotating at slightly different speeds to emit slightly different noise frequencies. I noticed, for example, on the 42RD deck I just worked on which had a new deck belt, clean pulleys, and a good belt tensioner that one blade would revolve ~2º further around for each revolution of the other two (which were much more closely sync'd) when I had it upside down and was turning the blades by hand. I finally found that pulley was ever so slightly bent so it's "belt circumference" was slightly shorter than the other two. I did my best to straighten it but it still isn't perfect. Haven't noticed any "thrum" dissonance but we mow with ear protection that blocks a lot of sound! 1 2 Share this post Link to post Share on other sites
Jeff-C175 7,202 #88 Posted July 11, 2022 (edited) 55 minutes ago, Handy Don said: revolve ~2º further around for each revolution I'll look at that closely before I reinstall the deck, (which will be soon) thanks for that idea! Edited July 11, 2022 by Jeff-C175 2 Share this post Link to post Share on other sites
Jeff-C175 7,202 #89 Posted July 11, 2022 Yes, they are in fact all turning at different speeds. I started with the three spring clips lined up with the blades via a straight edge on the side of the blade. After ten revolutions of the center blade it's clear that it's revolving quite a bit slower than the two outer blades and that the two outer blades are 'close, but no cigar'. After 20 revs the left blade in the pic is nearly lined up again with the center, and 22 revs on the right blade. I'm going to repeat a few more times to see if I get the same results... (definition of insanity?) After that I'm going to remount the deck and see if balancing that one blade that was slightly out made any difference. And after that, I'm going to wear ear plugs and simply ignore it if it still is trying to Woo me. 2 2 Share this post Link to post Share on other sites
Handy Don 12,234 #90 Posted July 11, 2022 1 hour ago, Jeff-C175 said: I'm going to repeat a few more times to see if I get the same results... (definition of insanity?) I was about to calculate the differences in the effective pulley circumferences -- but speaking of insanity! The reality is the way the belt rides at different places on the pulleys is gonna vary by load and engine speed. I recommend 3M ear protection! 2 Share this post Link to post Share on other sites
Jeff-C175 7,202 #91 Posted July 11, 2022 (edited) 1 hour ago, Handy Don said: I was about to calculate the differences in the effective pulley circumferences -- but speaking of insanity! The reality is the way the belt rides at different places on the pulleys is gonna vary by load and engine speed. I recommend 3M ear protection! I repeated several times and got the same result. I actually did some calcs, but not the pulley diameter... If the outer blades pick up 1 revolution for every 20 of the center, I figured that meant they were running appx 5% faster. I don't know how fast they actually turn, I may get out my tach and take some measurements if I get bored, but let's say the center is turning 3000 RPM? (not sure if that's even a reasonable guess, may be fast?) Anyway, if so, I think that means the outer blades are running 3150 RPM +/- In spite of all that... balancing that one blade seems to have cured the Wooos. But, it could be a combination of things. I didn't mark which blade came from each spindle and just put them back on any old way. When I remounted them I 'eyeballed' to be sure I got the blade as closely centered on the spindle as possible. I don't know who makes the yellow squishy ear plugs I use, but they really cut the noise way down! I've got tinnitus and pretty severe high frequency loss and don't need it to get any worse. I recently changed eye doctors... and one of the questions regarding pre-existing conditions was about hearing... I answered: " I can't hear my wife, but then maybe I ignore her." The Doc and staff were cracking up when I went in for my exam. The Treasurer was with me and she was not amused! Edited July 11, 2022 by Jeff-C175 1 2 Share this post Link to post Share on other sites
Horse Newbie 7,072 #92 Posted July 11, 2022 My wife says “Don’t talk to me from another room… I can’t stand that”… she says from the other room… 2 Share this post Link to post Share on other sites
biged77 113 #93 Posted July 11, 2022 I'm glad you cured the WOOs. I havent had this problem but I do use a noise cancelling headset when mowing so maybe I just don't know it. I have wondered in the past if slop in the hole could cause balancing problems and based on your experience maybe it does. I try to center them to the extent possible like you did. I wish the clearance was tighter. As for the two reinforment plates you added underneath, I did the same just before the bolt heads broke through. I think this is a design flaw but only for guys like us who expect them to last indefinitely. 1 1 Share this post Link to post Share on other sites
Horse Newbie 7,072 #94 Posted July 11, 2022 29 minutes ago, biged77 said: I think this is a design flaw but only for guys like us who expect them to last indefinitely. I guess you could call it a design flaw, but if it was made with thicker metal I’m sure it would last longer. Must be plain old metal fatigue… treat ‘em gently, and keep ‘em clean, they probably would last a lifetime. Look at the ones we find that are abused for 25-30 years and we bring em back. Don't see why with proper care, proper use, and proper maintenance, they would not last 40-60 years… 1 2 Share this post Link to post Share on other sites
Handy Don 12,234 #95 Posted July 12, 2022 1 hour ago, Horse Newbie said: Don't see why with proper care, proper use, and proper maintenance, they would not last 40-60 years… You have stated my plan in one sentence! 1 2 Share this post Link to post Share on other sites
8ntruck 7,016 #96 Posted July 12, 2022 Ya know, you really have not solved the problem unless you can remove your solution and re-create it. At least that is what the corporate QA statistical problem solver gurus claim. Me, I tend more towards if it is fixed, quit messing with it and document what your fix was in case the problem shows up again. 3 1 Share this post Link to post Share on other sites
Horse Newbie 7,072 #97 Posted July 12, 2022 12 hours ago, 8ntruck said: if it is fixed, quit messing with it and document what your fix was in case the problem shows up again. That’s probably what Taryl would do… 4 Share this post Link to post Share on other sites
