Lawn mower blades

My lawn mower blades get dinged up real good by sticks and small rocks. Grinding them takes me a long time, 2 blades, 4 edges.
Is there any reason why I couldn't set up the angle in the mill and clean them up with an end mill? I would think this would be a lot faster. I could always grind in the final edge.
If this isn't a good idea, then everyone should forget I asked a stupid question.
Wayne D.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 05/09/2011 04:10 PM, Wayne wrote:

I've seen someone here report on doing it just that way for commercial mowers.
Given that the blades seem to be fairly soft (and that they need to be, as one may not want one's blade to fracture), trying to get the World's Sharpest Edge on one's lawn mower blade may just be a waste of time after the first 100 blades of grass get cut.
--

Tim Wescott
Wescott Design Services
  Click to see the full signature.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Soft? I don't think *that* soft, and a super-TOUGH material.... holy shit.....
I think the op's complaint about grinding is precisely because these blades ARE so tough!
Milling, I think, would be fine, but my lawnmover blades seem to have some complex angles and twists. But if you can set up your machine to do it, and it doesn't eat up yer end mills, then it might be a good strategy.
Mebbe clamping the blade in a bench vise and having at it with a 4 1/2" angle grinder would be effective, as well. As time alluded, you don't need a chef's edge here.
--
EA


trying to get the World's
> Sharpest Edge on one's lawn mower blade may just be a waste of time after
  Click to see the full signature.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That'd be me.
Oregon makes the blades for the Scagg 61" commercial mowers. They are _adamant_ about milling them with a face mill rather than grinding them.
They supply them as new milled, and they specify the angle and remaining width of cutting backup area for new milling. Until they become narrower than spec, you just keep on milling new faces. I get about 30 acres per sharpening for a three-blade set now, up from my original 18. It has more to do with the fact that I've finally cut up and and not now re- cutting all the thatch than with the method.
I built up a permanent angle jig out of a block of 6061 to hold mine, and use a small carbide insert face mill to produce the edges.
One benefit is that it never overheats the metal. The other is that they come out virtually perfectly balanced every time.
LLoyd
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On May 9, 7:14 pm, "Lloyd E. Sponenburgh" <lloydspinsidemindspring.com> wrote:

Many years ago when I was clearing property with a Gravely two wheel tractor, I used hard surface welding rod to build up the cutting edge of the 30" mower. Never had to sharpen that blade again. One time I hit a piece of RR track buried in an anthill. Busted a two inch chunk from the RR iron but the blade did not even get a nick. Been 45 years ago and I do not remember what rod I used, just that I used an electric rod but applied it with a torch.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I have 20" carbide blades on my 21" self-propelled mower. I thought I would try them before spending $90 on a set of mulching carbide blades. I am not sure if they are available anymore.
---------------
"Gerry" wrote in message
Many years ago when I was clearing property with a Gravely two wheel tractor, I used hard surface welding rod to build up the cutting edge of the 30" mower. Never had to sharpen that blade again. One time I hit a piece of RR track buried in an anthill. Busted a two inch chunk from the RR iron but the blade did not even get a nick. Been 45 years ago and I do not remember what rod I used, just that I used an electric rod but applied it with a torch.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Lloyd E. Sponenburgh laid this down on his screen :

Maybe you could take a picture and post it next time you have it setup.
Wayne D.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I'll try to remember to. I have a sharpening coming up in a few weeks. We're in a drought right now, and I haven't had to mow in three weeks.
LLoyd
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I saw one of those programs on cutting devices, and the blades for those machines that eat anything were sharpened with some very simple grinders mounted at the proper angle.
But then, how would one test the proper angle on an actual lawn, and how would you know when you had it just right? I'd say that close enough would be close enough, even with a hand held sharpening device. At that rpm, even a blunt edge would cut, but definitely anything with any angle would leave a little cleaner looking lawn, and perhaps even produce a more shredded mulch.
Steve
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Steve B wrote:

I'd start with 20 degrees (I think) - that's the angle you're suposed to hold your Boy Scout knife while stoning it.
But I once bought a mobile home that came with the mower, and the blade was BLUNT! A buddy across town had a wheel that he mounted in his hand drill, and eyeballed it, and it made a world of differencce!
Cheers! Rich
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Try it. Let us know if it saves time. My guess is it will take longer unless you got a nifty quick way to mount at an angle. Of course, I have a nice six inch bench grinder with a coarse stone. If you got a smaller grinder, the mill may come out faster.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It will probably work, but I can't see it being fast.
Try an angle grinder and discs rather than a bench grinder. Works way faster for me.
There's no need, or use, in getting every nick all the way out - you go mow, there will be new nicks.
Belt grinder would probably also work faster.
--
Cats, coffee, chocolate...vices to live by

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 5/9/2011 8:26 PM, Ecnerwal wrote:

I just use a file, doesn't heat up the steel, doesn't take _that_ long.
--
<:3 )~

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mouse wrote:

Well, yeah, if you sharpen the blade about once a week. ;-)
Cheers! Rich
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I just use a brush hog first.
--



Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Yeah, I've used both, but now I only use a little 4" angle-head grinder. The wheel isn't quite as cool-cutting as a coarse wheel on a bench grinder, but it's so much easier to hold the right angle, and to see what you're doing, that the job goes much faster even though you have to let the blade cool after every few passes.
Not that the stuff they make blades out of is likely to suffer from some overheating, but I just hate to see that blue color on steel while I'm grinding it.

Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Wayne wrote:

Actually, it sounds brilliant! I once spent almost two days standing in front of the bench grinder making a blade from scratch out of a piece of spring steel, 3" x 1/4" (about the size of a mower blade). But I admit I'd be a little reluctant to cut spring steel on a mill; but ordinary A36 or even O1 should be a snap. And you could get that "hollow ground" effect by using the right size of ball end mill. :-)
Have Fun! Rich
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
http://www.canadiantire.ca/AST/browse/2/OutdoorLiving/PowerEquipment/LawnMowerAccessories/PRD~0606107P/Lawn%252BMower%252BBlade%252BSharpening%252B%252526%252BBalancing%252BKit.jsp?locale=en
http://www.canadiantire.ca/AST/browse/6/Tools/PowerToolAccessories/SandingPolishingAccessories/PRD~0544899P/Lawn%252BMower%252BSharpener.jsp?locale=en
----------------------
"Wayne" wrote in message
My lawn mower blades get dinged up real good by sticks and small rocks. Grinding them takes me a long time, 2 blades, 4 edges. Is there any reason why I couldn't set up the angle in the mill and clean them up with an end mill? I would think this would be a lot faster. I could always grind in the final edge.
If this isn't a good idea, then everyone should forget I asked a stupid question.
Wayne D.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Belt grinder with a coarse belt fixes mine up in short order. Lotsa rocks... Don't need a scalpel edge for whacking grass, a 40 grit one works just fine.
Stan
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Slightly off-thread:
I once had a 30" Gravely mower with a monster blade: about 3/8" thick by 3" wide & 30" long. As the end kept getting narrower and narrower from sharpening and I put off buying a new one ($$), it occurred to me that I could make it into a flail mower by cutting off the narrow ends and bolting on short flails. Those flails could even be pieces of 21" mower blades, which could be had for no cost (dump).
I sold the mower before I had to do anything about the blade, but would the conversion-to-flail have been a good idea?
Bob
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.