Ledger plate sharpening?

[Mountain_a]

Hi all
I have an old John Deere no 5 sickle bar that I think needs some repairs. I believe the ledger plates on the guards are worn. I see some sources saying you can sharpen them with a bench grinder or flap disc, others say you cant at all. I have the ones with the serrated edges. What’s the best way to go about sharpening them? To my knowledge, you want no rounded corners so I plan to take off the ledger plates, and buff them against my bench grinder a few times, hitting the surface on the stone with the side that faces up and with the sickle teeth when attached to the guard. I assume I just want a hard 90 degree angle against that and the serrated edges and then debur it, Is that correct? Let me know, thank you!

 

[paul]

Seems like a lot of work, at that point I would put new plates on?

We would do a quick dress up with an angle grinder on smooth guards where the sickle had the serrations. While everything was still assembled.

In either case you are removing metal and changing how things cut with each other. Your way you would need to adjust the hold downs and the sickle would end up pitching down slightly as I think the back of the sickle would be higher than the front where you are removing metal? The back of the sickle will still be riding on the guard, but you lowered the ledger plate?

In our way of doing it the guard gets narrower and so by the second sharpening the sickles and the guards wouldn’t cut as much across each other.

In any case sharpening helps but doesn’t restore things to perfect; I wouldn’t go through the work of taking all the plates off to sharpen and then put together again with the used plates. I’d consider a quick dress up with an angle grinder to help out in season but know that it’s a temp type of fix….

Paul

 

[Absent Minded Farmer]

Paul brings up a good point. Any metal removed will change the necessary gap & pitch between the section & plate. Most manuals will give you the correct info on those specs for your mower.

Things would go a lot quicker & easier for you, should you choose to just rivet in new plates.

Mike

 

[SadFarmall]

Paul brings up a good point. Any metal removed will change the necessary gap & pitch between the section & plate. Most manuals will give you the correct info on those specs for your mower.

Things would go a lot quicker & easier for you, should you choose to just rivet in new plates.

Mike

It is a good point. Clearance between ledger and section is important. Getting the correct edge would be difficult with the ledger in the guard. Incorrect settings require greater energy, that is fuel, to run the mower. With tractors and operator can just use more throttle. With older, horse drawn mowers, the horses tire out faster. Basically, if you want it to work well, it needs new ledger plates.
SadFarmall

 

[spacechem]

I used to sharpen ledger plates, but I had to quit- it was cutting into my nail-straightening time...

 

[rrlund]

I've still got a box of them out in the shop. Dad used to knock the rivets out and change them. I think they're like disposable razors blades, meant to be used and thrown away.

 

[560Dennis]

Suggest just drilling out rivets and replacement of ledgers with modern replacements that fit. Not that costly and a way effective way your mower will perform for a long time.
Surface could be case hardened . That would mean more surface removed then the steel becomes softer more material removed.