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

great help chaps i think going back to the place of sharpening will be the go thanks again....

No probs Steve, please let us know how you get on.

g day well i took a trip to the guy who sharpend my cylinder blades he gave em anther quick relief grind it seems i was not ajusting the cylinder cutter down enough thats about the size of it what i did work out for myself was that by folding a piece of newspaper in two so to make it thicker to resemble a blade of grass it was spot on good sissor action i think what im trying to say is it will come out in the wash regards chaps steve.....

deviosi,

If the cylinder is set correctly it should cut thin paper. I have set cylinders to cut tissue paper in the past for bowling clubs and they cut all the way through the cylinder.

The trick is not to have the cylinder to tight against the bottom blade and when it is running it should sound like it is humming with no ticking noise or clanging.

Good to see that you got it all sorted out.

thx bruce can u tell me what is the diff between a relief grind and a full grind from what i saw the relief grind is done by hand moving the cylinder cutter left and right whilst a cutting wheel sharpens it. and the other is a bit more involved and automatic once set up and takes some time but i think more precise anyways regards steve...

Hi Steve, if I could wade in at this point, there seems to be a bit of debate on the point of full grinding (or "Spin" grinding as it is known) and relief grinding.
Here is some information I have found....It relates more to the tolerances required when cutting the dwarf type grasses found on golf greens and possibly bowling greens.

SPIN GRINDING VS. RELIEF GRINDING

The most advanced reel sharpeners offer features and methods to accomplish a complete regrind that includes single blade relief and spin functions. Others cannot, so the debate between spin grinding only and spin plus relief has emerged as a hot topic � as is the comparison of �scything� vs. �scissor� actions. Spin grinding alone produces a sharp cutting edge and is often compared to a scythe, which produces a good quality of cut as long as it remains sharp. Keeping the reel sharp can require the time-consuming task of regrinding during the busy periods of summer. If the reel blades are not maintained to a sharp edge, then the bed knife must be kept sharp by facing or filing the front edge of the bedknife. With no relief, the reel blade thickness could cause increased drag as debris is brought between the reel and bed knife. A gap of one to two thousandths of an inch is recommended between the reel and bed knife when you spin grind alone.

On the other side of the debate, if you add a relief grind or grind the back side of the reel blade off as to produce a very thin land area, you can adjust the reel to the bed knife with virtually zero clearance between the two. With new varieties of ultradwarf turf and heights of cut well below 0.100 of an inch, you can measure the amount of leaf tissue being removed only in microns.

A scissor action is attained when the reel in conjunction with the bed knife creates a shearing type action. Just like a pair of scissors, the two blades must be maintained extremely close to each other, so close that measuring would be impractical. The natural juices in the grass blades act as a lubricant and actually keep the reel blade and bed knife at near zero contact. If you want to have increased performance, you can do so by making the reel blades thinner by relief grinding, that is, by grinding away the backside of the blades.

If you have relief grinded your units, a two- to three-minute back lapping replaces the tedious and time-consuming task of removing cutting units and regrinding. Also, doing so will help you maintain a much more precise relationship between the reel and bed knife than front facing the bed knife in an attempt to keep the units cutting properly. This is a very valuable asset in the busy mowing months. By keeping the reels properly adjusted to the bed knife, you ensure that a consistent sharp edge is always maintained. The key to keeping a reel mower cutting properly is in keeping it adjusted. A reel mower is often considered a self-sharpening instrument that will stay sharp if the gap between reel and bed knife is kept intact at �zero� clearance; however, if you allow the reel to become dull due to lack of adjustment, it will not resharpen itself.
Hoping that this might be of interest, Steve.

Steve, here is a little more on the topic.

Myths about Spin Grinding

There are a lot of myths out there about grinding. In this issue we tackle two common myths with Express Dual and Anglemaster user Peter Fletcher, owner of PMG Consulting Services in Alicante, Spain.

The self-confessed �miserable old codger� is anything but miserable or old. Peter has been travelling the world recently helping to prepare some of the world's best golf courses for major tournaments.

In May and June of 2007, Peter has travelled around the world providing tournament support at the Volvo China Open, the BMW Asian Open, The Celtic Manor Resort Wales Open, the Open de France and the Italian Open. Along with an impressive amount of air miles, Peter has a tremendous amount of experience using spin grinders and here he helps us set the record straight.

Myth: Blade thinning keeps blades sharper, longer.

Fact: �Blade thinning, or relief grinding as it is commonly referred to, has no effect on sharpness at all. Relief grinding is carried out on the back edge of the blade and serves only to �relieve� the drag caused by contact between cylinder and bedknife. It is the front edge of the blade where cutting takes place.�

Myth: Quality of cut is guaranteed with a sharp reel and bedknife.

Fact: �The most important element to ensuring quality of cut is a sharp bedknife. A sharp bedknife (faced bedknife) will cut grass cleaner with mediocre sharp reel blades vs. a rounded edge bedknife and very sharp reel blades.�

well deejay the sharpening plot thickens thanks for your reply's it serves as good infomation as bruce said he has cut tissue paper for me to acheive that the contact would be to heavy so ill be m,aking sure the ajustment is giving that very slight tickety tick thanks all steve.....

all i have a question for cylinder mower capabilities to keep a nice edge around my gardens i use a spade to keep the edge strait what im getting at is when i use my brushcutter to nick the grass that has grown at the edge it throws some of the tea tree mulch onto the lawn what i want to know is how much can the cylinder cutter cut/chomp without damage dont get me wrong im carefull about the area that is to be cut running my eye the lawn which i have been bettering for some time now i think it goes with the terain using a cylinder mower and the look u can acheive cheers steve...

The mower can cut clean, thin bark without harm but it should not be asked to cut thick bark, let alone woodchips. It especially must not cut sand or grit. If you look at the stuff that you call tea tree mulch by the time it gets whippersnipped and thrown across the lawn, you'll probably find it contains lots of sand and grit, and very likely some woodchips as well. There might even be a few paperclips, kids' toys and loose mower-parts included.

I suggest you look closely at it, then think about whether it is suitable for mowing.

Hi Steve, as usual, good advice from Grumpy there, mate. If in doubt, use a fine rake and drag it all back into the garden.
For my edging I use a Victa Tilt-A-Cut which throws the grass and litter forwards, so I don't have much of a prob there.
For ferrous metallic objects, I removed the magnet from an old hi-fi speaker, tied a length of strong garden twine to it, so as I can drag it over the lawn, if I suspect I have lost a nut, bolt or screw.....better safe than sorry.

thx deejay for your reply about how much can a cylinder cutter handle.i have a question what color was the cylinder cutter on the SCOTT BONNAR 45 MOWERS the 1 ive just about finished has a kirby 2.5 hp and its orange in color can u confirm that the cylinder cutters were orange on the early scott bonnar 45's kind regards steve....

Hi Steve, you are quite correct there, mate, they were the same colour orange as the Briggs, and also the orange on the handle decal, on the later machines. Personally, I prefer Fire Engine Red on the cylinder reel, and had mine done in 'Powder Coat". I have never been a big fan of the orange colour!!

g day!All well deejay sorry to disapoint but im gunna stick to the original color merry chistmas steve.....

i notice that the clock time is different to the post time anyway cheers

Hi Steve, and Merry Christmas and a Happy New Year to you and yours.....Yeah mate, once I replaced the Briggs engine with a Honda, I lost the originality with my machine, so I powder-coated a few of the parts in red, to match the engine cowling colour. But as yours has the original engine, orange will look the part!

did the powder coating set u back much deejay? steve...

Hi Steve, I had to have the cylinder reel sand blasted first; (after carefully masking the areas where the bearings sit) and from memory that cost around $20.00. The other parts I stripped myself, and the powder-coating cost around $45.00.
That was a few years ago, if you are thinking of doing the same, I would get a quote first. The reel did look better than new afterwards.
BTW...The reel needed sharpening, so I had it powder-coated first, then spin ground after.....

some pics of my SB 45/17 with original kirby 2.5 hp model number 45 00867 made in 1968 when scott bonnar released the 45 range of cylinder mowers merry chistmas steve...

Well done with that machine, seeing those two pics made me excited in the pants area!

some more pics s/b 45/17 rebuild merry Christmas Steve...

some more pics s/b 45/17 rebuild merry Christmas Steve...

Steve that is a fantastic job you have done on the Scott Bonnar. It looks better than a new one on a job well done.

Hi Steve, I wish to echo Bruces comments, just brilliant!!
You should feel very proud of your work, just like a bought one!!

thanks for the kind comments all it went from just a clean up to a full pull down this 1 was not as much work as it was in good order the fuel tank has a internal filter as the tank had dried leaded old fuel and i think rust but a few weeks of clean clean clean i got it to a usable state with filter and replaced o rings in fuel tap merry chistmas steve...

Hi there Deejay (and others), I have a Model 45 and a Diplomat (ugh!) and have long lost patience on the cruddy old Briggs and Stratton vacuum choke carby system etc. For the 45 ...I can purchase for $285 a new (2008) 3hp B&S from a mower shop who bought it for a customer job which didn't go ahead but I feel I would rather go to the Honda. Any advice? And what model Honda did you use or recommend? Any issue with shaft sizes, keyway, shaft height and centering from the base/mounting plate? Throttle cabling etc? Is there a forum on how to do this?
Any pointers gratefully received.
Phantomguy.

Hi Phantomguy and to the forum. I am sure that Darryl (Deejay) will be able to help you with the information regarding fitting a Honda to your mower.

The mounting holes will line up without any trouble at all and all you will have to do is make sure that you get the correct shaft on the Honda engine. I am sure that Darryl will give you any other information that you will need soon.

Hi Phantomguy. and a big warm welcome to the forum. I have had a hectic festive season and I am sorry for the delay in response to your question.

On my Scotty I have a Honda G100 2.5HP. These engines have been superseded by the GX range, and are apparently very strong for their size.(and start first pull)!!

Click HERE

You can click on the model range on the right to see all the various sizes.

I had my Honda fitted by a local engineering firm in Wagga, (Judds Engineering) who also happen to be the Honda dealers for this area. As far as I know, there were no probs encountered, the horizontal engine shaft mated properly with the cylinder clutch, and even the 4 bolt holes that attach the engine, aligned perfectly.

I actually had only 2 problems with the original engine.....one was called Briggs and the other called......
Viva La Honda!! he he!

What a great restoration.. Awesome attention to detail!

Can anyone tell me the paint brand, colour name and finsh type used on Deviosi's resto? The green and orange?

Eg.
Galmet - Brunswick Green - Metallic Finish

Septone - Chevy Orange - Heat Proof Finish

Is it necessary to use a heatproof paint for the engine or can I use say a regular galmet rust proof flat colour? I want the cutting reel and engine the same colour though seems silly to use heatproof paint on the cutting reel. I would rather use a specific rust proof paint on the cutting reel such as galmet, septone or killrust and if used on the engine will it be ok and withstand the engine heat?