Now on to forming up the stringers. Hit a snag right out of the gate on this. I went and bought a ring roller,
reluctantly. There is only one source I could find for these, through various sellers of course. It appears we don't
make one here (USA) anymore, that I could find anyway, and the ones being imported are not very good quality, I
did find that out looking around. So I finally bit the bullet and purchased one. And as expected, it was problems.
This ring roller is a tube roller as well, and it comes with a bunch of different dies for tubing, the square dies are a
50 dollar option. Thought they were a bit pricey for three 4" diameter rolls from them, considering the same folks
sell a drill press with motor and all for the same price :) Ah well...
Anyways, I go and get this thing and it's heavy, almost a hundred pounds, I pay the almost 250 dollars and bring it
back to the shop. After assembling it, I throw a piece of 1/8" X 1/2" strip in there just for the hell of it and turn the
lead screw to start forming an arc, and nothing happens, it just spins and clunks occasionally. Low and behold, the
hole that the leadscrew goes through has no threads. I wondered was I missing something, did I need to engage
something? Was I jumping to conclusions? Nope, it had no threads. And the bad part, I wasn't surprised.
In the pic below, It's the big gold leadscrew in top with the hex drive.
reluctantly. There is only one source I could find for these, through various sellers of course. It appears we don't
make one here (USA) anymore, that I could find anyway, and the ones being imported are not very good quality, I
did find that out looking around. So I finally bit the bullet and purchased one. And as expected, it was problems.
This ring roller is a tube roller as well, and it comes with a bunch of different dies for tubing, the square dies are a
50 dollar option. Thought they were a bit pricey for three 4" diameter rolls from them, considering the same folks
sell a drill press with motor and all for the same price :) Ah well...
Anyways, I go and get this thing and it's heavy, almost a hundred pounds, I pay the almost 250 dollars and bring it
back to the shop. After assembling it, I throw a piece of 1/8" X 1/2" strip in there just for the hell of it and turn the
lead screw to start forming an arc, and nothing happens, it just spins and clunks occasionally. Low and behold, the
hole that the leadscrew goes through has no threads. I wondered was I missing something, did I need to engage
something? Was I jumping to conclusions? Nope, it had no threads. And the bad part, I wasn't surprised.
In the pic below, It's the big gold leadscrew in top with the hex drive.
My Steamboat Project Link to steamboat show
The Steam tug "Salty" built from Reliable Steams' plans Page 10
The Steam tug "Salty" built from Reliable Steams' plans Page 10
So I had to weigh up my options at this point, do I lug this gem back to the store, then come back and make my own
or would it be cheaper to just fix it? I opted to just fix it. Everything else about it seems to be ok, fairly heavy, It's
not very precise, but I can live with that, for what I need it for. So I went to the rack and drug out a piece of 1-1/2"
dia 4140 tool steel and proceeded to make an 1-1/2-12 leadscrew, which I have a tap for the same. A few hours
later, it was reassembled and working. Seems to work pretty good, I wouldn't want to use it all day cranking that
screw in and out, but it will suffice for this job and the occasional use it will see. (edit: it was perfect for this job)
The pic below shows the new leadscrew.. (I Know this has nothing to do with building a tug, but I just felt like
sharing this :)
So on to the stringers after that little ordeal..
It took a little practice to get familiarized with the roller. Then it was pretty easy. Just lay the stirnger in the
frameslots, and take a marker and put an X where it need more or less arc. After a few, I got fairly proficient with it.
And both sides being symmetrical, once I made one, I just made another to match for the other side. Nothing to it.
I cut the stock in half to make it easier to handle, once the two halves are running the full length and following the
hull shape, just pull them together and butt weld.
Below shows one half stringer:
It took a little practice to get familiarized with the roller. Then it was pretty easy. Just lay the stirnger in the
frameslots, and take a marker and put an X where it need more or less arc. After a few, I got fairly proficient with it.
And both sides being symmetrical, once I made one, I just made another to match for the other side. Nothing to it.
I cut the stock in half to make it easier to handle, once the two halves are running the full length and following the
hull shape, just pull them together and butt weld.
Below shows one half stringer:
Then I modified the rollers to accept 1/8" and 1/4" material. This ring roller was perfect for this job. With the big
T-handle it was easy to control the bend. They sell these with a hydraulic jack, that wouldn't work as well, I wouldn't
think. Not being able to control the arc very precisely. The difference between the lead screw setting from not
enough to too much was around 1/4 turn on most of the stringers. Which is probably about .015 - .030" adjustment.
Would be hard to do with a hydraulic jack.
The pic below shows the grooves:
T-handle it was easy to control the bend. They sell these with a hydraulic jack, that wouldn't work as well, I wouldn't
think. Not being able to control the arc very precisely. The difference between the lead screw setting from not
enough to too much was around 1/4 turn on most of the stringers. Which is probably about .015 - .030" adjustment.
Would be hard to do with a hydraulic jack.
The pic below shows the grooves:
Once it is fitted, then I just formed up another to match for the other side. This old tub most be parallel side to side,
the second one always fit like the first with no adjusting.
the second one always fit like the first with no adjusting.
As with everything else on this, once I figured it out, it went pretty smooth, the rest of the way.
Once the roller debacle was resolved, this went pretty smooth. They are not welded into the frames, they are just
left loose, while the skin is laid. That is the next step on page 11.
left loose, while the skin is laid. That is the next step on page 11.
