Posted tagged ‘making large wooden screws’

NUTS! What one can learn from failure

August 21, 2011

I’m very happy to be in possession of a couple of nuts from Lake Erie Tool Company.  They’re beautifully made.

Nuts from Lake Erie Tool Company

As I mentioned to you in a previous post, I highly recommend that you buy your wooden bench screws and nuts from a vendor who is set up to manufacture them on a production basis.  Okay, the screws are easy enough.  Make them if you want to, but I’m still suggesting that you buy the nuts and save yourself a whole lot of headaches. 

Never being one to take my own good advice, I just had to try to come up with a way I could produce a higher quality nut for my own use with stuff I already had in the shop.  I had produced several screws that were undersized and I didn’t want to waste them.  So why not waste three or four days of my time instead?
I decided I could use my lathe as a spindle to hold a fly cutter.  I ground down an old spade bit and made a fly cutter with two 60 degree cutting edges.

Then I figured that I could use my “lunette box” from the screw making machine.  I could use the same lead screw.  All I had to do was make a hub with a couple of stand-offs to support the nut blank.

Then I’d use a center plug and mount the blank and simply slowly turn the blank into the flycutter and voila, a perfectly formed nut.

Okay, pull the plug, turn on the cutter, turn the leadscrew….

Then it all went awry.  Cumulative clearances, an over-extended leadscrew, a “too thin” cutter all came together to form the perfect storm.  Overwhelming vibration set in.  And, try as I might, I simply was not man enough to restrain the whole thing.  I did succeed in creating several nuts, all of which were over diameter and not nearly concentric. 

Though I lost a couple nice pieces of hard maple, I was reminded of a valuable lesson: failure can be a much better teacher than success, assuming that you can kick your ego out of the room while the class is being held.

So, once again I say unto you, make a screw, buy your nuts.

I think I’m gonna try to repair my old wooden tapscrew.  What the heck?????

Making Wooden Screws – Lessons Learned

August 5, 2011

Well, just a few minutes ago my big wood tap screw went KABLOOIE!!  It was made out of cherry, so I didn’t expect it to have an extremely long life.  I’ll have to make another one, maybe.

If you’ve been reading the blog over the past few weeks you know that I became completely enchanted by the big wood screw making process.  Now I can share with you the wisdom I have acquired as a result of this process.

Three wooden bench screws in ash (it’s tough and it’s what I had on hand)

If you’re willing to put in the time (and a little money), making the screws is pretty simple stuff.  The nuts, on the other hand, are difficult to make, at best.  They’re not that challenging in a technical sense.  It’s just extraordinarily laborious work.  Using the type of traditional tapping machine that Underhill shows (shown in previous articles in this blog), the nutmaking process requires hours of manufacturing time and a significant amount of elbow grease.  Fitting is required and though serviceable, the internal threads show an appreciable amount of  damage, created when the scraping cutter traverses the “against the grain” quadrant of the “face grain” presented block.

The nuts are the HARD part!

 The long and short of it is this:  I’m glad I did it.  And since I’ve built the fixturing, I may well make more screws in the future, a few for working, a few as gag gifts.  But my STRONG suggestion is this – BUY THEM.  Wooden bench screws are great for any bench application.  For hundreds of years they were the standard.  They’re still great!  But do yourself a favor, buy your bench screws from a reputable supplier; someone like Lake Erie Tool Works .  If you want to make your own screw, so be it.  But save yourself a lot of headaches and buy the nuts.  You’ll be glad you did.

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