Bandsaw Blade Crack Failure

In my shop I have two bandsaws.  The large 7” one hardly ever sees use any more as I no longer take on large projects.  The inexpensive small 4” one I have raised up on a stand so it is at standing working height.  It sees use every day cutting smaller stock when a need a clean and straight edge.

I use bimetal blades and go through about five per year.  I have noticed that when a blade is at the end of it’s life the saw arm developes a subtle up and down deflection which gradually increases in amplitude until the blade breaks.

The cause of the breakage is invariably a gullet crack.    Sometimes, I can find partial cracks in addition to the complete break.  I have chosen to just live with the situation rather than take the time needed for a full investigation and correction of the root cause, but for those interested here is a link to common causes of gullet cracks.

http://www.sawblade.com/common-causes-of-gullet-cracks-in-band-saw-blades.cfm

Apparently cracks also can originate on the blade back side also and here is a link to investigating those.

http://www.metalsaw.com/Back-Cracks.cfm

Loosing blades to crack propogation probably doesn’t cost me as much as making a mistake when trying to cut some tool steel stock.  I have learned to observe very carefully as the bandsaw blade starts to travel across the stock.  If chips aren’t flying off as they usually do, I stop and use my presto marker pen to write, “No bandsaw”, on the stock.  That material will need to be cut with an abrasive blade or possibly with the torch or hot cut with with a hack with my hydraulic forging press.

http://www.persimmonforge.com/

Cone Mandrel Sharp Cap

My favorite cone mandrel is an old heavy cast type positioned in my acorn table work area.  However, it has a blunt tip and the smallest ring I can form on it has a diameter of about 1.5”.  Often, I want to form a tighter radius, so, I made a work-around tool to permit that work.

I made a symmetrical trapezoidal pattern 7.5” across the base, 5.75” tall and 4.5” across the top. I rolled a cone from 10 gauge sheet scrap and MIG welded the seam.  Then I hot fitted the hollow form cone sleeve to the tip of the cone mandrel.

Next I forged a piece of 1.25” round to a taper a couple of inches long which closely matched the line of the cone sleeve.  That solid tip was welded to the cone sleeve and blended for a smooth transition of the surfaces.  

Finally, I welded a large punch drop to the base perimeter to serve as a knock-off flange in case the tool got tightly jammed onto the mandrel.

This tool works really well.  It’s simple.  Probably, it is not original, but I’ve never seen another.  It can be made in less than a half hour from scrap and it has saved me a lot of time and frustration.  My nickname is “the witch hat.”

Offered for what ever it is worth.

http://www.persimmonforge.com/

Instructions, Models, Step Sets and Storyboards

In my last post I put an image of a storyboard which I typically make for repetitive projects to illustrate all the steps.  I keep the instructions in the box containing the tools, jigs, blanks and whatever is needed to make the particular item.  I have been very busy doing a lot of that kind of work lately - making things which have sold out in the gallery.  Fortunately, the weather has been very mild and pleasant for early August.

Back on 7/10/2011 I wrote about one of the garden items I make for dispensing nesting fiber for birds.  It is a simple vortex with a hanger and a loop which can be hooked with a spike tipped pole and hung as high us as that reach allows.  It can be filled with string, yarn or gathered vine and grass segments.   Obviously the nest builders get most of their material from other sources but when they do tug out a piece of yarn it is entertaining.

The sales success of some of these small garden items has been remarkably more than I anticipated.  As the sales numbers rose I was faced with finding the most effeceint way to make more of them for the gallery so I can  move on to more creative work.

Last week, I was told that the gallery sold out of the fiber dispensers, so I needed to make more.  I got out the box and went to work.  The story board make the job easy.  This a well worked out project, fully jigged.  I cut ten of the required lengths of rod using a hack die in the hydraulic forging press.  This method pinches off the pieces with a nice taper already started.  With coal fire heat a round taper was drawn on both ends.  Scroll pliers and a crook jig was used to form the standard hanger hook.  Just below that I coiled a single loop which was bent to form a lifting “hole”.  On the other end a 90º bend was made a couple of inches from the tip and with several heats I rolled up a coil about 3” in diameter.  That was the end of the coal fire work.  

The coil was opened into the vortex by hammering with a ball peen hammer over a ring jig held in a vise.  This was done cold.  The torch was used to heat the point where the coil transitioned to the hanger shaft.  A 90º bend was made at that point and the shaft was twisted at the same time to make sure the hook lined up over the mouth of the vortex.  The completed dispenser is put in the tumbler for cleaning away all the fire scale before applying the lacquer finish.  I learned the hard way not to put ten of these into the tumbler at once because the intertwine to form something like a Gordian knot.

Organizing these simple projects in this way makes them move quickly and not seem boring.  I should mention, too, that most project boxes contain a finished model and perhaps a step set too.  Invariably, when I make a quantity of pieces there will be at least one which goes awry.  That piece can become the “shop model” if it’s not too far off but not nice enough to be sold.

When I pack up a project and plan to store it away until the next production time I record on my inventory spreadsheet (a file on GoogleDocs) where the box is stored.

For some projects I keep some nearly finished components unassembled so if a client requests some variation of a standard item I can accommodate them fairly easily.  That exact thing happened yesterday when a client came to the studio with a sunflower she had purchased and wanted a hanger added and also a leaf - both were right at hand.

http://www.persimmonforge.com/

Back to Work

I’m finally back to making things.  After the recent coal trip I was cleaning t he bed of the pickup and managed to take a clumsy plunge down onto my left shoulder blade area.  Not since high school football days had I taken such a hit.  For the first week my arm mostly hung uselessly as the bruise spread down the upper arm to the forearm.

Fortunately we had a vacation trip to California planned so that worked well in my healing schedule.  When we got home a heat wave greeted us so I had an excuse to postpone forging a while longer.  It also gave me the opportunity to do a lot of lighter work assembling pieces which could go in the gallery.

Now the situation is looking good.  My left arm is about 90% back to work.  It looks like the heat will be with us for a while so I’m going to concentrate on assembling products which can be done in the comfort of air conditioning.  And it gives me time to think about things I might post on the blog.

When I was beginning my smithing business I set up to do commission work and had no plans to do craft shows or make products.  However, reality set in.  People saw some smaller things I made for our own use or for gifts and wanted one for themselves.  It didn’t take long before I had a line of products.  I’ve come full circle now and spend most of my time making things for the gallery which sell again and again and  much less time on commissions.

The repetitive nature of working this way has pros and cons.  The downside is largely related to boredom of non-creative work.  The upside is largely related to learning how to work more efficiently and perfectly.  It is interesting to study how to make design improvements, better tools and jigs and other aspects of production.

Some of my products have a really good sales record so I’ve naturally concentrated my efforts on those.  In the last couple of years It has occurred to me that it might be possible to sell my business somewhat piece by piece or product by product.  Each project has its set of dedicated tools and jigs and instructions which make it possible for any other blacksmith to make it.

Soon, I plan to go into more detail about my strategy for organizing each project.

http://www.persimmonforge.com/

Oklahoma Coal Again

I checked the date and it was almost exactly a year ago when I went to the coal mine for a load.  When I’m running low I tell Betty and she calls the scale house to confirm that they will have coal crushed to appropriate size for smithing and checks the price and makes sure our anticipated arrival time will work.  Everything looked good for a run today.  The price had gone up from $125 to $130 a ton.  US green folding money, of course.

To get a more useful price I have to figure in the hours and mileage and gasoline cost and lunch before we head back.  The actual cost is really $300 - $400 a ton delivered and in the bin.

Orio, one of my great helpers, did most of the driving.  The weather was perfect.  We saw many box turtles crossing the backroads in their summer migration and the wildflowers were beautiful.  The country was much greener than in the past couple of years when drought has gripped this region.  By the time we got to the mine at 1125 there was evidence of recent rain with water standing in the low areas.  

We weighed in and drove to the loading area for “chicken coal.”  We opened the bed and got back as a huge front end loader scooped up a partial bucked load, probably it could hold 10 cubic yards or more, and carefully filled the truck.  We leveled it off and worked it into all the corners.  This was too far to drive for a partial load.  The coal was wet and this made loading less dusty but we surely paid for some water.  We got the bed cover closed and weighed out, paid and were gone in about 15 minutes with just a bit over a ton.

Now it was time to look for a place to eat.  We found a nice buffet in Coffeyville, Kansas with salad, fried fish, ribs, chicken and great bread pudding.  I had never been in town when the Dalton Museum was open, but today my luck changed.  We spent an hour looking over the displays and I would definitely recommend it to travelers, especially those interested in western history and gun enthusiasts.  $3.50 is a bargain price.

One unanticipated pleasure for me was learning about the Patty Page connection with Coffeyville and seeing some of the material they have collected relating to her vocal career.

There was an interesting video playing which reenacted the events of the Dalton’s failed bank robbery.  One thing it points out is that this is an early example of average citizens who were just not willing to take any more of this thuggery.  In 1894 most people wren’t wearing iron on the hip any more so they rushed to the hardware store where guns and ammo were quickly distributed and they took up positions to block the escape of the gang.  The rest is history which you can see at http://www.daltondefendersmuseum.com

We were home before dark, still too stuffed to eat supper.  The weather is perfect to sit outdoors and enjoy the evening and later it will be great sleeping with the windows open, but tomorrow somebody is going to have to shovel all that coal into the bin at the studio.

http://www.persimmonforge.com/

Another Online Reference

Well, it’s too hot to forge again and I have been really busy with other things so there hans’t been much to post.  I am about to start assembling sale items from the hundreds of parts which have been forged already.

The time away from the studio has been used to clean out a lot of files on the computer and in the hanging file cabinets.  It has also allowed me to do some more web exploration looking for items of blacksmithing interest.  This is one I thought would be worthwhile to share.

http://www.fao.org/docrep/009/ah637e/AH637E00.htm

Today it may only be 85º so the forge will get fired up.

http://www.persimmonforge.com/

Grandfather was a Blacksmith

Almost every smith will say that from time to time a visitor will announce, “My grandfather was a blacksmith.”  Eventually, that event will become less common.  Blacksmith numbers are not what they were a century ago.

One of the friends, Scott Miller, who often helps me can confidently claim his grandfather, Jim Lewis, was a blacksmith.  He has the proof of it.  A history of his hometown, Lebo, Kansas, contains a photograph of the grandfather and great-grandfather standing by the door where they burned the cattle brands of their rancher clients.  The old building stood from the 1880’s until 1951 when it was replaced by a Quonset hut, which became widely available for civilian use after WWII. http://en.wikipedia.org/wiki/Quonset_hut

Scott has a good eye for design, a devotion to technical competence and the strength to pull it together so one more branch is forming on the blacksmithing craft tree and someday there will be others who can say, “My grandfather was a blacksmith.”

http://www.persimmonforge.com/