OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Scott Bonnar 45 17"

Hi all new to the forum. I recently purchased a Sott Bonnar 45 17" re conditioned and have a question about the cutter. When I adjust to cut paper both ends bottom out and if I set to clear the center does not cut. Can anyone advise me do I need to have the cutter sharpened?

The cylinder will never fully cut paper, if it creases the paper it will cut grass nicely.

Hi staffee, and welcome to Outdoorking.

The reel is not perfectly matched to the bedknife. Possibly there is a slight curve in the bedknife. Whether that is cause for action is less clear however: it depends how much clearance there is in the center. If you have the reel perfectly adjusted, with no metal to metal contact anywhere, how much of the width is cutting the paper? If it is cutting for most of the width, I think everyone but the true perfectionists would try it on some grass, and probably be awestruck by how well it cuts. For the remaining 0.73% of reel enthusiasts who insist on perfection, I think the answer would be backlapping rather than a regrind. However it is all about how much of the width is not cutting the paper, and how sharp the leading edges of the blades and the bedknife are. You can inspect that visually and by the finger cutting trick.

Please let us know how sharp it is, and what percentage of the width is cutting the paper, then we can talk about what action, if any, is appropriate. Incidentally a couple of pictures would be great: seeing the mower, and the way it cuts the paper, would get us all thinking in the same terms.

It cuts only the outside 2" .I have cut he grass (couch) and the result is very good the best I have ever seen but i get a line each side of the cut and it requires me to go over it again to even the cut. The mower has a new bed plate and it may be the problem .Thanks for the response.

It sounds as if you need to check the bedknife with a straight edge. Is there any possibility that someone replaced the knife blade and didn't have it ground flat after it was mounted on the soleplate? That is definitely not a workable thing to do. The reel and bedknife have to be ground as a pair, and matched together.

Hi to Grumpy, please hear me out here; too much emphasis is being placed on the cylinder reel cutting paper... this is not an emphasis that a greenskeeper puts on his machine or his expertise on the set-up....this is something that has been thrust upon we cylinder mower owners through absolute garbage and is a "myth ".

I have tried to explain the correct procedure here on paper, but to no avail, most everyone thinks you have to cut paper...please; to all that are interested; watch the video coming soon; ( Scotty Model 45 Reel and Soleplate Removal and Re-Installation Guide) on the adjustment procedures and form your own opinions.

I adjusted the Model 45 carefully yesterday, with Joe Carroll kindly videoing the adjustment procedure...I fed in a piece of paper and it cut it almost completely in two...that was a piece of A4 computer paper... but the vision is not on the video deliberately... because the results were flawed, the setting was much too tight... I re-adjusted to give clearance, I then completed the adjustment to what I believe is correct; it creased the paper... and we then took the mower out to the lawn and I asked Joe to do two passes over the lawn...it cut absolutely perfectly; cutting the grass as one would do with a pair of scissors...These machines are meant to cut grass; not paper...and there is a subtle difference... I don't want reel mower owners all over Australia trying to cut a piece of paper for the whole reel length, when the whole exercise is an absolute farce!!

If, in fact, it does cut paper...then there is no clearance; the bottom blade is contacting the cylinder reel and is not adjusted correctly...Crease the paper; all is good, cut the paper the setting is too tight....A reel mower is not a pair of scissors...it is a grass cutting machine, adjusted to very fine tolerances...Not a paper guillotine....
Here endeth the lesson....

How stupid am I.... this is the Introductions Topic....Sorry guys..we've gone way off topic...Slap on the wrist for Deejay!!

Staffee, a warm welcome to the forum, Its good to have another Scott Bonnar Model 45 owner on board.

Sorry Deejay, I was the main culprit. I've moved the thread to Questions on Scott Bonnar Lawnmower Frames.

Your mower was a pleasure to use Darryl, and I am honored that you trusted me to give it a drive

Thanks for all the reply's the bedknife was replaced and it has not been ground to match the reel. I know because I spoke to the guy who restored the mower. I made some further fine adjustments and it has improved the cut. I think I will get the reel sharpened in the new year. Again thank you and a Merry Christmas.

staffee, if the reel has been freshly sharpened and your only problem is that it does not match the bedknife, it is a bit frustrating because the reel can only be sharpened a limited number of times before it runs out of meat and becomes useless. I suggest you speak to an expert at your local bowls club or the sharpener they recommend, to see what can be done without regrinding your reel. They may be able to just grind your bedknife, then lap the reel and bedknife together.

Hi grumpy...that is good advice... the engineer would be the one to speak to...he would know the grind angle of the reel and could grind the bedknife to suit. Some engineers do what is termed a 'relief' grind; this may be the case here.

However, all should be able to be fixed without re-grinding the reel again.
Staffee, don't forget to take the soleplate complete with the bedknife attached to the engineer, with the cylinder reel.
You may consider replacing the reel bearings also...at least then you will know the history of the reel, bedknife and bearings under you stewardship.