# DIY Cylinder mower grinding tool - my solution



## msvec (Apr 25, 2020)

Hi, I have been using my vintage cylinder mover Honda HC 18 for 9 years.Thi is unbeatable old school mower with great Honda G100 engine and really solid cylinder. Up to the present days only backlapping has been my grinding method, but i have looked for some better grinding solution - and finally i found it - I built really cheap jig within 3 days of work and hard thinking. Two linear rails from china eshop (about USD 40) some pieces of metal sheet scrap and my angle grinder(125 mm size). As you can see at the pictures, a few metal pieces, bolts - and that´s it. 
This jig is an universal tool for cylinder and bedknife too. I use 180 mm grinding disc for cylinder grinding (you have to reduce speed at 125mm angle grinder because of angular speed overrun !!) and standard 125mm grinding disc for bedknife - in this case the angle grinder has to be rotated 90 degrees in the jig and removed from the mower together with jig as a whole. 
Unfortunatelly, I have no video of my jig tool, but as an example, how it works in principle, you can watch this video on Youtube, i got idea from this solution :





Maybe my idea helps you ! Greetings from the Czech Republic, Europe.

Some pictures of my grinding tool here:


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## Buffalolawny (Nov 24, 2018)

Very good.

Does the grinding disc hit the reel at the same angle as would the reel to bed knife?

Do you re-mate the reel to bed knife after sharpening? Like if one side is thou of an inch higher one side due to flexing, adjusting to cut paper and then you grind the reel flat. Adjusting the reel back to the bottom blade will curve the cutting surface.


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## msvec (Apr 25, 2020)

Yes, it´s important to tilt and fix the grinder stand in correct position - grinding disc must hits the reel bellow the reel central axis, not in centre or above. And the second important thing- as you can see at the pictures bellow, red marked support holder must be adjusted appropriate under the grinded blade to keep the blade in fixed position. This measure provides correct cutting angle within the grinding process.





About the bed knife grinding - not visible at the pictures, but in this case the jig is demounted out of mower and the bedknife is carefully fastened at the side profiles.Then i will take a measurement, because of knife has to be precise fastened parallelly towards to the linear rails. Angle grinder stand has to be tilted into the correct position against the bedknife blade and makes correct cutting angle.


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## Buffalolawny (Nov 24, 2018)

Well done.

Seen a different setup on a lathe jig. Using an belt sander air tool. The small type air tool The lathe rotates the reel. Then it's setup to flatten the bed knife. Much like making a leg for a stool


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## Greendoc (Mar 24, 2018)

I can see using such a jig for relief grinding the trailing edge of the reel blade. How are you ensuring that the height of each reel blade is the same. Grinding the face of each blade individually became a less used technique because spin grinding was a simpler way to remove the coning or taper from the reel and ensure each blade was of the same height on the reel.


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## msvec (Apr 25, 2020)

Yes, spin grinding is a better way, but there is a problem for me - here in the Czech Republic reel mowers are not so popular as in UK or USA, so there is a lack of professional cylinder grinder service in my close area.. Not comfortable for me to travel 100-200 km to the nearest service.. And in case of my vintage mower, cylinder dissasembly is not easy, so my idea was to do it as easy as possible..
Well, technique is simple. The position and angle of the grinder is fixed and invariable during whole grinding. Each blade is grinded from left to the right side no more than 1-2 x times during one stage. Then I shift the disc to the edge of rail, it enables to turn the reel by one blade, next blade follows.. After first round completion the reel is to be drawn closer to grinding disc by adjusting the bolts at the reel, so you can repeat this process until the blades are well sharpened. The abrase of disc is absolutely minimal during one step/round, so the height blades difference is insignificant. Yes, of course, this is not professional solution, but sufficient for my gardening. And really cheap solution for handymen, as i wrote, about 40 USD and some work..


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## Buffalolawny (Nov 24, 2018)

Another option is to buy a 1 inch roll of material backed sand paper to lay on the bottom blade like this one.


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## mowww (Jan 16, 2018)

@msvec very cool, thanks for sharing!


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## clehn8ok (Oct 13, 2020)

Hi msvec,

you really did some outstandig work here. not to complicated, well engineered.

Since i am from austria, and those mowers are also very uncommon here, i am also planning to build something similiar.

Do you have plans for this build? 
or did you build it, as it was in your head?

Why did you use a 180mm disc for the reel but a 125mm disc for the bedknife?
Which size are those linear rails SBR12?
are the linear rails bolted to a metal plate, spanning from one side to the other?

do you have some pictures of the bedknife grinding? or could you explain it to me, how you do this with this jig?

Thank you so much


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## sangheili (Jul 5, 2020)

Really cool project and great job with the build. Are you worried about the ground material jamming up the linear rails? My experience is they are a bit fragile.


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