WC 68 blade change & bed plate

[tcalvin48]

Real basic question; the manual for the WC 68 says to use new nuts when changing/reversing the blades. Is this really necessary? This is the first I've seen this for reusing nylon locking nuts.
Any suggestions for adjusting the bed plate? It is pretty much not visible to me, lighting is a real issue.
Thanks,
Tom Stoltz
in Maine

 

[rc51stierhoff]

When nuts are tightened if deforms (cuts/compresses) threads(bolts are same way) doesn’t matter if nylon or a locking metal nuts…I would think nylon would not be damaged as much as metal but I don’t really know. They can be reused, correct torque is the key IMO. I think virgin nuts () would be much less like to loosen…I would think that is a an ‘idiot-proof’ comment from manufacturer understanding not all use a torq wrench all the time. I think correct torque is your friend on your nuts (). I am sorry I am never grew up. . Maybe the vibration would loosen them (used ones with less holding strength)quicker, but they need to be at correct holding pressure (torque) I would think?

 

[58Ford]

Lock nuts - with the nylon - were always single use I thought.

 

[rc51stierhoff]

It’s probably not a bad idea and really not very expensive…might be worth it from that aspect while you are in there…would not be helpful if one came off. Either way I think tightened to correct torque is important.

 

[jkrubi12]

Well, I just got a WC68 TODAY and I managed to get a quick look at the blade mounting bolts and iirc (too dark to go out & look right now) there are 4 per blade, and they are allen head tapered flush-fitting bolts. I thought the mounting bolts screwed into the flywheel, but I really didn't scrutinize the system that closely. The 'bed plate' (aka the 'anvil'), which attaches & adjusts from the side, uses 3 bolts with the nylock nuts exposed, along with the plate adjustment screw (haven't figured out exactly how that works yet).

I looked at mine to estimate the 'clearance' between the blades (sharp!) and the anvil, it's between 1/16" & 1/8" and even along the entire edge, which I believe is the specified clearance. Those blades are so sharp you could easily slice your finger on them, amazing!

 

[NCL4701]

As you know, the bed plate is located near the bottom of the flywheel housing where it is difficult to see and pretty much impossible to measure as there’s simply no clearance to get any sort of normal measuring instrument in there. Further, not only does the gap have to be right, the bed plate needs to be parallel to the blades. It isn’t a high precision adjustment but I couldn’t even get a reasonable “eyeball” guesstimate on something I could barely see.

I had to set the bed gap once. I made a scrap board into a 2’ long x 2” wide “feeler gauge” by re-sawing it with a bandsaw to 1/4” thick and then ran it through a planer to get a final thickness of 3/32”. Figured a board would be sufficiently non-compressible to work given the generous acceptable range in gap and wouldn’t dull the blades. After setting the gap with the 3/32” x 2” x 2’ board, nothing crashed and it chips stuff like it’s did before, so the available evidence suggests success with the feeler gauge board.

 

[DeepWoods]

I used a different approach to setting the bed plate. I used dykem on the plate and scribed a line on the plate where it touched the knives then another line the correct amount back for the gap. Then I used the second line to set the gap. I agree with others, the visual inspection is very difficult to see if it is set correctly. The picture isn’t the best, but you can kind of see what I’m referring to. I have rotated my knives once already, but did not replace the nylocks. Did some research on the subject, and will now replace them every other time I rotate the knives. Just as a precaution as they are not that expensive and can only imagine the destruction if things came undone.

 

[jkrubi12]

I had to use a flashlight to look down & see the knife/anvil relationship, after rotating the top cover aside.

Nice pic @DeepWoods!

 

[tcalvin48]

, the bed plate needs to be parallel to the blades.
[/QUOTE]
I have rotated my blades and replaced the nuts. I experimented with the old nuts and I think they can be reused. Maybe the suggestion of using them only one more time is a good idea.
Now the bed plate; I did get a light to where I could see reasonably well and found guestamating the spacing depends on how you view it. looking down from the top seemed to have a wider space than looking sideways at the blade/bedplate interface. I ended up using the sideways view. In the sideways view, my bedplate is not parallel to the blades. The lower on the bedplate, the closer it is to the blade. The bedplate is parallel to the side of the housing. I did try raising the back end of the bedplate to get top closer to the blade but decided against that.
The bedplate has always been like that, not parallel to the blades, but parallel to the housing. What have you found?
Tom Stoltz
in Maine

 

[NCL4701]

, the bed plate needs to be parallel to the blades.

I have rotated my blades and replaced the nuts. I experimented with the old nuts and I think they can be reused. Maybe the suggestion of using them only one more time is a good idea.
Now the bed plate; I did get a light to where I could see reasonably well and found guestamating the spacing depends on how you view it. looking down from the top seemed to have a wider space than looking sideways at the blade/bedplate interface. I ended up using the sideways view. In the sideways view, my bedplate is not parallel to the blades. The lower on the bedplate, the closer it is to the blade. The bedplate is parallel to the side of the housing. I did try raising the back end of the bedplate to get top closer to the blade but decided against that.
The bedplate has always been like that, not parallel to the blades, but parallel to the housing. What have you found?
Tom Stoltz
in Maine
[/QUOTE]

My OM says to make the gap uniform along the entire edge of the blade so that’s the way I set mine.

 

[tcalvin48]

My OM says to make the gap uniform along the entire edge of the blade so that’s the way I set mine.
[/QUOTE]
Right, but you have to angle the BP to make it parallel? That part doesn't seem right to me. I would think that the BP sits flat and its edge is square and that should be parallel to the blades. Mine dose not look that way. I would have to really raise the the back of the BP to make it parallel to the blades.
Tom Stoltz
in Maine

 

[NCL4701]

My OM says to make the gap uniform along the entire edge of the blade so that’s the way I set mine.

Right, but you have to angle the BP to make it parallel? That part doesn't seem right to me. I would think that the BP sits flat and its edge is square and that should be parallel to the blades. Mine dose not look that way. I would have to really raise the the back of the BP to make it parallel to the blades.
Tom Stoltz
in Maine
[/QUOTE]
On mine, the rear of the bed plate assembly which is visible (as shown in DeepWoods’ photo above) appears to be square with the gap in the housing when the blade is parallel to the knife. It does seem odd that the bed plate assembly would have to be canted to square the bed plate with the blades.

 

[XSpecBx]

As others have said, when you tighten the nut down, it cuts threads into the nut which is what holds it in place. Where I work, there is a minimum breakaway torque required for nylon nuts to be reused, but they generally just get replaced, especially for rotating machinery.

In this case, I wouldn’t risk damage to the equipment over some inexpensive nuts. It’s probably fine to reuse, but I wouldn’t for the above reasons.