Correct torque for Byrd cutter replacement?

[Robert Chapman]

I need to replace one of the cutters on the Byrd helix cutter head on my Powermatic 15HH planer. What is the correct torque when installing the cutter on the head?

[Rich Neighbarger]

50 inch pounds

[Myk Rian]

Make that 55ip.

[J.R. Rutter]

between 50 and 55 in lbs ;)

[Ken Garlock]

Gentlemen, you hit on one of my pet peeves.:eek:

1. a foot-pound is not a measure of torque, regardless of what NASCAR may think. It is a measure of work done.

2. a pound-foot is a measure of torque. It is a measure of a mass acting upon on a lever of a known length. That lever is normally acting on a nut, bolt, drive shaft, at a known distance from the pivot-point.
Think of a child's seesaw. One side has a mass,the parent at some distance from the fulcrum, the other side has some other side has a mass, the child, acting at some distance from the fulcrum. Both the parent and the child are applying torque, hopefully, counter of each other.

[Myk Rian]

Gentlemen, you hit on one of my pet peeves.:eek:
Whatever. We're not talking about those anyway.
It is all used in either order, and people know what is implied.

[Alan Schaffter]

Be careful, don't let Ken's post confuse you- the torque used for Byrd inserts is in inch-pounds (or pound-inches :) ) NOT FT-LB (or LB-FT).

This means you won't be using a typical automotive torque wrench which operates in the FT-LB (or LB-FT) range. If you torque to 55 FT-LB (or LB-FT) you will over torque and crack or shatter your inserts.

You need a smaller, IN-LB (or LB-IN) torque wrench. Though less common you can find them at HF.

As others have said, 50-55 is the correct number. And yes, Ken is correct- torque is measured in pound-feet or pound-inches.

[Brian Gumpper]

If you want a pdf copy of the tip replacement instructions, PM me your email address because I don't think I'm allowed to link to it on my site.

[Ken Garlock]

Be careful, don't let Ken's post confuse you- the torque used for Byrd inserts is in inch-pounds (or pound-inches :) ) NOT FT-LB (or LB-FT).

This means you won't be using a typical automotive torque wrench which operates in the FT-LB (or LB-FT) range. If you torque to 55 FT-LB (or LB-FT) you will over torque and crack or shatter your inserts.

You need a smaller, IN-LB (or LB-IN) torque wrench. Though less common you can find them at HF.

As others have said, 50-55 is the correct number. And yes, Ken is correct- torque is measured in pound-feet or pound-inches.

Hey gang I made the assumption that everyone knew how to divide by 12. I didn't intend to confuse. Yes, you can call it anything you want so long as you put Torque in the statement. You might even want to call it Kips-chain torque, or nanograms microns torque. After all, we are just trying to communicate. If everyone knows the unit of measure all is fine.

Note that I did say PET PEEVE. :o:)

[Robert Chapman]

Brian Gumpper sent me the official Byrd specs which say to use hard hand tightening which they define as "about 45 to 55 inch pounds of torque". Yes Ken - Byrd says "inch pounds".

Thanks Brian.

[Mac Cambra]

I guess I would have assumed that the commutative property would have applied to the units of torque, since it is basically just the product of the applied force and the length of the moment arm (assuming the force is orthogonal). That being the case you would both be right.

Then again what do I know I am an electrical guy.

[Mike Goetzke]

Robert - I bought Byrd heads for my jointer and planer from Brian. For the planer I remove all the inserts first to make it easier to install and allow for cleaning of the inserts and head. When I reassembled and torqued my common sense told me to push the inserts toward the stop shoulder while tightening. I was getting ridges at a few inserts. I called Byrd and they told me you should actually push them away from the stop shoulder while tightening - that did the trick and almost entirely eliminited and ridges.

Mike

[Robert Chapman]

Thanks Mike - The Byrd specs I got from Brian did indicate to push the insert away from the shoulder when tightening. As soon as my 0-50 inch pounds torque wrench gets here I'll replace the insert and see how the rest of them look. Found a piece of an insert on the bed of the planer but have not noticed a change in the surface quality of material planed.

[Gerald Senburn]

I got one of these last year. Pretty inexpensive yet perfectly fine for the rare times I need one.

http://www.amazon.com/gp/product/B000P91OXI

[Ken Fitzgerald]

When using most tools, their accuracy is best when used in the middle of their operating range.

Thus a torque wrench for example that goes from 0-100 lb.-ft. will typically be most accurate around 50 lb-ft.

You can convert lb-ft to in-ft by multiplying by 12.

Thus, 10 lb-ft equals 120 in-ft.



You can convert in-ft to lb-ft by dividing by 12 so 45-55 in-ft equals 3.75-4.58 lb-ft. On your typical torque wrench, this would be difficult to set and because it is near the end of a typical torque wrenches range, very inaccurate.

My advice is buy an in-lb torque wrench for use for these type of particular uses.

The torque wrenches I use at work have to be calibrated back to a NBS calibrated standard annually. While my home torque wrenches aren't, they will give me an average torque that will typically keep me from breaking a screw or bolt by gorilla'ing it and they will spread the pressure evenly by using the same standard evenly when using multple bolts or screws.