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Simplicity Sickle Bar knife adjustment


GardenTrACtorguy

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GardenTrACtorguy

I have a simplicity sickle bar that I broke knife bar on about four years ago. I had a new bar made and just got sections to put it back together in the winter months. I have part of the bar assembled and when I go to test fit the knife the tips of the sections seem to be really close to tips of the guards. Is this a wear plate or hold down clip issue?  Also I can’t remember for the life of me what holes the knife bar bolts to on the pitman arm. What holes do I use to get the right throw?  (Maybe shouldn’t  have waited four years and I might have remembered sm01). And for the chain adjustment I have the chain to where when I lift the bar for a turn it just barely lifts off the ground at the main skid shoe and the chain is slack when the bar is on the ground it that correct?  Thanks!

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Looks like about the same amount of clearance as the ones on he mower hanging on my 3310. If you look at your picture you can see where the  line is in the paint where your knives were running before. It looks about the same to me.

 

The bracket on the Pitman arm has 7 holes. The center and 2 outside holes are the mounting bolt holes. The 2 inner pairs of holes are there to let the heads of the rivets on the cutter  sections pass through, otherwise the bracket wouldnt lay flat  against the sections.

The threaded holes should be for a fine thread. Should be a grade 8 bolt and only long enough for the end of the bolt to be flush with the bottom of the cutter bar when tightened.  I use loctite when assembling those bolts.

 

I'd have to go out and look again to see how many links of chain I use, but When on a flat surface  the chain should have it so that the skid is just off the ground  when the bar is out in cutting position. Its how I have done it always myself. I'll see if I can find the mower manual I have laying around here somewhere and edit in what it says there later...

I looked and the manual I have does not say, however I have found that if the skid drags the ground its just going to continually end up balling up previously cut material on following passes. ( learned this while mowing a 12 acre  pasture with one of these once)

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GardenTrACtorguy

I had this bar made exactly like the old one that broke and the bolts are fine thread.  Is there a shim or adjustment for the hold down clips to the sections.  Thanks!

 

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12 hours ago, GardenTrACtorguy said:

Is there a shim or adjustment for the hold down clips to the sections.  Thanks!

Yes, there is a shim that goes underneath the hold down clips.

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GardenTrACtorguy
17 hours ago, SmilinSam said:

I looked and the manual I have does not say, however I have found that if the skid drags the ground its just going to continually end up balling up previously cut material on following passes. ( learned this while mowing a 12 acre  pasture with one of these once)

When I adjust the chain like that the bar tips forward when put in transport position that doesn’t seem right. Is there something else majorly wrong?

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1 hour ago, GardenTrACtorguy said:

When I adjust the chain like that the bar tips forward when put in transport position that doesn’t seem right. Is there something else majorly wrong?

If you attach the chain to the correct point,( see picture)

medium.DSCN1923.JPG.37ee1c3766f8613e15c7

 

when you raise the bar up, especially in transport position, its going to tighten the chain and pull the back of the mower up off the ground more, thus tilting the bar forward. Its Normal.

The bars do not stick straight out from the tractor either, so there is going to be some forward angle  when raised from just that too..

medium.DSCN1916.JPG.c192b1e786748cd86587

 

Heres a shot of the bolted up pitman arm plate...

medium.DSCN1922.JPG.05d21aea1bf4126a9285

 

As to the shims under the hold downs. They are actually wear plates. Simplicity part "BB"  #8161136 They are not so much meant to adjust anything, they just take the wear from the cutter bar being pushed back into the arm as you mow. They do wear out and should be checked periodically if any real time is put onto the mower....not that they are available any more, but could probably be made.

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GardenTrACtorguy
2 hours ago, SmilinSam said:

If you attach the chain to the correct point,( see picture)

medium.DSCN1923.JPG.37ee1c3766f8613e15c7

 

when you raise the bar up, especially in transport position, its going to tighten the chain and pull the back of the mower up off the ground more, thus tilting the bar forward. Its Normal.

The bars do not stick straight out from the tractor either, so there is going to be some forward angle  when raised from just that too..

medium.DSCN1916.JPG.c192b1e786748cd86587

 

Heres a shot of the bolted up pitman arm plate...

medium.DSCN1922.JPG.05d21aea1bf4126a9285

 

As to the shims under the hold downs. They are actually wear plates. Simplicity part "BB"  #8161136 They are not so much meant to adjust anything, they just take the wear from the cutter bar being pushed back into the arm as you mow. They do wear out and should be checked periodically if any real time is put onto the mower....not that they are available any more, but could probably be made.

My bar is closer to 90° perpendicular to the tractor.  I had trouble in the past with a bolt breaking at the drive and bar pivot area. That is where the chain is adjust and bolted to now on the tractor and sickle bar.

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On 12/6/2021 at 10:26 AM, GardenTrACtorguy said:

 

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I would like to take a mulligan on this one.  GTGuy, where did you get the bolts to mount the sickle knives to the bar?  Rivets are readily available in all sizes from McMaster-Carr and other sources but using bolts would be a bit easier.  The rivets Simplicity used are #6 (3/16" or 0.188") x 1/2".  Also what is the length of the bolts and what sort of nuts are used (thin, flanged, serrated, or ?)?.  I assume that they are #10 screws either coarse or fine threaded.

Thanks

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GardenTrACtorguy
32 minutes ago, CarlH said:

I would like to take a mulligan on this one.  GTGuy, where did you get the bolts to mount the sickle knives to the bar?  Rivets are readily available in all sizes from McMaster-Carr and other sources but using bolts would be a bit easier.

Thanks

I used 10-24 machine screws. The flat head screws have an Allen head and fit in the pitman arm holes perfectly to allow the mount to sit flat. I used lock tight on all of the section bolts. Looking to see how they’ll hold up. If I start to have sections loosen up or come off I will be going back to rivets. 

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GardenTrACtorguy
8 hours ago, CarlH said:

The rivets Simplicity used are #6 (3/16" or 0.188") x 1/2".  Also what is the length of the bolts and what sort of nuts are used (thin, flanged, serrated, or ?)?.  I assume that they are #10 screws either coarse or fine threaded.

Thanks

I used standard thin machine screw nuts. The bolts were 1/2 the same as the rivets. I tried 3/4 inch bolts with stop nuts but they rubbed the guards. I used blue lock tight on final assembly. 
I have only ran it once in the shop so far. I’m currently fixing a worn out hime joint on the reciprocating arm. Hoping the bolts will keep it together just as well as the rivets. I was looking more for serviceability using bolts. 

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