"slide arm" fuller

[Eddie Mullins]

I am kind of just thinking out loud here, so bare with me.  I have been thinking about making a swing arm fuller, but am not real certain I like they way the top arm contacts the material at an angle instead of parallel to the bottom arm and material. I noticed an adjustable swing arm on a Hofi BP and it got me thinking... why cant the top arm just slide up and down on the stem in the hardy?

 

Here's a crude excel "sketch" of what I am thinking. My thought is to go with square material so it doesn't rotate. I have old square tubing on hand now, so this will be a no cost experiment for me and I'll probably do this just to see what result I get, but if there is a glaring issue or this has been done beore please speak up and provide pics : ) .

 

[jeremy k]

As you hammer on the arm where you are doing the fullering - it will bind the sleeve that slides up and down on the solid bar in the hardy hole - thus you will get nowhere on your fullering, a pivot type with some flat bar and a bolt for height adjustment holes is the way to go, or a tool similar to the smithin' magician.

Or something as this picture:

[Matt Marti]

http://www.iforgeiron.com/page/index.html/_/blueprints/uri-hofi-series/bp1036-wing-nuts-01-r223  

 

Eddie look at Hofis take on side arm fuller.

[Frank Turley]

Build a guillotine style?

[Eddie Mullins]

Jeremy - I built a guillotine that I am still tweeking to suite me, just kind of in a tool making mood as of late. I thought binding might be an issue, but am willing to spend a few minutes to find out since I have the stock on hand. Your pic did make me think I might be able to use my tubing to make something in that style.

Matt - That link just took me to the main pages area. Did you see a Hofi BP? Here is a pic of the Hofi fuller I spotted in on of his BP's for something else.




Frank - I guess we typing at the same time : ) . I built a guillotine, just enjoying exploring options in tool design using the material I have on hand.

[Judson Yaggy]

Should work if you don't mind some wear/beating happening to the sliding parts.  Put a shoulder on the square stem to keep it from falling thru the hardie hole, and file the weld seam off the inside of the tube.  Make the tube as long as you can to prevent the system from wedging into a locked position.  Make GOOD welds.  

 

Alternatively you can bend a piece of round bar down into the hardie hole, back up and out, into a loop, and along the face of the anvil.  No welding or slide fits required.  Basically bend 24 inches of round bar in half so it looks like a big hair pin.  Stuff the bend into the hardie hole 2 or 3 inches.  Bend one end down to the anvil face.  Bend the other around into a sort of sideways question mark, with the straight leg of the question mark parallel to the bar on the face of the anvil.  Thin the curved portion of the question mark if you want to be fancy or need more spring in the working end.  Presto, spring fuller no welding required.  Mild steel will work fine, do all the bends hot.  

[Matt Marti]

Exactly Eddie, I saw it in Hofi's wing nut BP a couple days ago. I hope that will help you!

[jeremy k]

Eddie - after seeing Hofi's picture - it's like your drawing, but it does have a pivot bolt and the slide sleeve locks to the post w/ a set screw/bolt/nut. So after seeing Hofi's picture that you posted, it makes sense what you were trying to accomplish in your first post. Your almost there!

[Glenn]

BP1036 Wing Nuts 01
by Uri Hofi

 

[VaughnT]

I was contemplating a build similar to Hofi's when I recently built my swing-arm fuller.

 

Two things I've noted:

 

The bolt hole spacing makes for a big difference in how the fuller impacts the workpiece.  While it would look like there's an odd angle of incidence, that is changed by the hole spacing and the distance from the fuller bit to the pivot point.  The thickness of the stock also plays an important role in how the depression in the workpiece looks.  You'll not see anything untoward in 1/4" stock even if your arm is a bit high or low.

 

There is a tremendous amount of force applied to where the arm joins the upright.  Even with a bolt to pivot on, the hammer's blow will get transfered back into that joint and the whole contraption likes to jump up and down in the hardy hole.

 

An arm with infinite adjustment like Hofi made will need to have a pivoting bolt or you'll always have the tightening screws scraping up and down the vertical shaft with every strike of the hammer.

 

Having said all that, I do like the adjustment of the Hofi design.  I don't think it's a necessary thing, but it would a whole lot easier to wrap a piece of stock around the upright than it was to drill a dozen holes.

[Frosty]

If you really want parallel dies build a double arm like you see in some treadle hammers. It'll need to have really stout arms but two, one over the other and the top die will stay oriented regardless of it's position in the swing.

 

Frosty The Lucky.

[Eddie Mullins]

I think we are proving the theory that if you want 12 opinions on how to do something you just need to ask 8 smiths LOL. Keep it coming guys, good pointers and options, my gears are turning.

 

I know there are proven designs out there I could copy, but whats the fun in that. I don't need the fuller, just want to build a different one, using what I have on hand, and with out nonessential complications.

[jeremy k]

Eddie - in a pinch (and another person is handy) a set of round reined tongs can be used as a fuller also - been there done that when the guillotine was left at home.

[Eddie Mullins]

Initial dry run seems very promossing. No binding. Will finiished the weld up and fire up the forge to see how it actually functions by the weekend. I'll give an update when I do.