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The basis of the bead roller is a frame of 4"x2"
box. It should resist the spreading force at the rollers and
have provision for clamping in a vice.
The gears will dictate the size of the rollers. I used two
identical gears from my lathe.
The handle is another item from my lathe.
- 3 pieces of 4"x2" box 18" long, for shaft
supports and long upright.
- 1 piece of 4"x2" box 12.125" long, short
upright
- 1 piece of 1" diameter bar 21" long, top shaft
- 1 piece of 12 diameter bar 20" long, bottom shaft
- 3 pieces of 1.75" OD 3/8" wall tube, 1.5"
long, shaft bushes
- 4 pieces of tube as thrust collars, I used 1.25x 14swg
tube
- 2 pieces of 1 x 1 .2502 steel, form upper front adjustable
"bush"
- 2 gears , I used 2.650 diam' x 32 tooth
- 1 adjuster , I used a 12 mm x 120mm socket head
- 1 handle , nicked from my lathe
- 2 pieces of 2.625 diam' x2"
List 1, Materials and parts required.
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Figure 1. SW view of beadroller frame, the bushes that take
the shafts are shown as well as the upper "bush" and the adjuster
screw. |
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Figure 2. Shafts, the top is 1" longer than the bottom.
The longer shaft is for the handle to fit on. The 3/4"
endfloat-collars are mig plug welded to the shafts
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The dimensions of the frame will depend on size of the gears,
I will assume you are using the same gears as I used. The
frame is made from items 1-3 in list 1.
The two shaft supports were placed on the bench the correct
distance apart, this distance depends on the gears being used.
The pieces of box were clamped to the bench and the first
upright, the short one, was tacked in place on the shaft supports.
The clamps were removed and the second upright clamped in
place. The second upright was welded to the shaft supports
then the first one was welded in place. The difference in
length is so it can be clamped in a vice while being used.
The bush placement was decided, then the upper and lower
back bush and the lower front bush were welded in place. The
two pieces of flat stuff that form the sliding bush were also
welded in place; these are shown as two pieces of flat stuff
welded to the upper shaft support, really they were pieces
of angle cut and welded to form a box.
The shafts must turn freely in the bushes and the upper back
bush must allow the shaft to be moved vertically, so the sheet
metal can be slid between the rollers. I used thick walled
tube for the bushes, I found it in my scrap bin, it was a
good fit on the shafts, a couple of thou' clearance. The back
upper bush was filed so that it allowed vertical movement
of the shaft. The front bush and "adjustable" bush
must retain the shaft and prevent sideways spreading of the
frame, there is .010" side play in the top bush and 2
thou' in the bottom bush; the frame didn't seem to spread
sideways so those sort of clearance's are OK. When welding
the bushes in place there is no need to weld all the way around
them, I only welded the ends of the back bushes in fact, the
loading is against the frame and you don't want to distort
the bushes. The adjustment screw had the end that bears on
the shaft ground flat, this is crude but works. If you intended
on using it for full time work I would suggest loads of changes
including a sliding bush.
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The shafts were made from 1" mild steel bar, items 4
and 5 in the list. The differences in the top and bottom shaft,
was the extra length for the handle. The handle was put on
the top shaft, I can't think of a reason why it should go
on a particular shaft though. The shafts have thrust collars
welded in place at the roller end. The collars had an 8 mm
hole drilled in them, then they were plug welded to the shaft.
The collars that go at the gear end of the shaft are retained
by the gears. The shaft bushes could be placed so they protrude
beyond the frame, then the thrust would be taken by the gear.
The amount of endfloat doesn't matter to much when rolling
a bead, the rollers line up automatically. There must be enough
endfloat so this can happen. While rolling a step the rollers
will separate, if they are allowed to separate to much, they
won't roll the form you designed the rollers to roll. I didn't
tighten the bolts holding the gears in place when rolling
a bead, so there was plenty of endfloat, when rolling a step
the bolts were tightened giving 5 thou' of endfloat.
The gears and rollers were retained radialy by drilling
a 6 mm hole axially into the shaft and roller, or gear and
roller, then sticking a pin in the hole. This worked quite
well, it was quick and easy. When making new rollers put a
piece of 1" scrap in the hole to aid in drilling the
pin hole.
The rollers were cut from freecutting steel, there's nothing
complicated about the shapes for beads and steps though it
does get more complicated when flanges are rolled. The rollers
don't take long to make so I made some of them by trial and
error. The only thing I did wrong with rollers for beads was:
not allowing enough side clearance or not radiusing the edges
enough, they were like a pair of scissors.
For any other details e-mail me.
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Figure 3. rendered drawing of the rollers for rolling a bead. |
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Figure 4. profile of rollers in Figure 3, these are cut with
angled profile, all edges are straight, then a file was used
to put a radius on the edges. Approximate radius is 100 thou'.
When making rollers the thickness of the metal to be rolled
must be allowed for. I allowed for 16 SWG.
I machined a very fine line on the centre of the roller,
this was used for guiding the rollers.
I left the polythene on the front face of the aluminium being
beaded, the lower face in this setup.
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