hi I'm Paul Brodie I'm here with Mitch he operates the camera and this is my shop welcome our project
today is a head tube hauling fixture this is one here there's an older one over here I'll show you
quickly how it works here's a head tube engine eight head tube put that over a second cone here
and then there's a clamp now you notice that on the clamp and the second taper here there's
a ramp and each of these ramps matches so you put this on you lock it and then you twist it
and that really locks in the head tube there what's going on with this and it works on an
intranet head too but for the larger head tubes like a paragon 44 millimeter it's too small so
I've got some metal here it's GOM it's drawn over mandrel that means it's seamless tubing
we're going to make a couple larger cones here so this one here we have to undo the weld we
have to take this off make make the cone put it back on there do a little weld this one's
a little bit more involved because it also has to have a ramp going down we're going to
do that on the mill using the rotary table and the digital readout first step is to go into
the lathe machine this down a little bit file the well press this off let's go I don't have
to machine off the whole thing but I'm going to take cuts going back maybe a quarter of an inch
and I'm going to go really close to this inch rod but not into the rod have to be careful
okay I'm very very close I think what I'll do now is I'll file off the weld and then we'll go
to the arbor press and we'll press the shaft out from the taper it seems like every video we do I
end up doing some filing the press oh it's coming out really easy so I don't even need of the press
there you go okay then okay that's soft I'm go to the lathe of this one and we'll we're gonna
make a taper now what we're gonna do is to move the compound this is this is the compound we have
to loosen off the bolts well the nuts on either side and turn it at an angle it's a 20-degree
tape so I'm gonna get my protractor out and we'll set it up they go there's my 20 right there I'm
just eyeballing it if it's off a degree it's okay okay I like that right there make it tight
that looks okay it's not absolutely perfect but it's smooth I have to put a handle on it as well
so what I'm doing for that I've got a piece of I've got a 3/8 bolt so often we make make the
cone we're gonna put it in the mill we're gonna drill a hole we're gonna tap a thread I'll cut
it off Loctite it in there make it really tight with the hex and then we'll cut it to length so
it'll be like that that's basically how it's going to be except on on the larger one so
let's go back to the lathe I have to do this whole process once again but it doesn't take that long
off off to the mill now we're going to use the mill like a drill press we'll
start out with a center drill it's short and stubby no flex
so that's the tap drill so what I could do now I could take this out hold that in the
vise and get a tap handle and tap the hole but I could be starting at a slight angle
whichever way so I'm gonna hold this in the Chuck I'm gonna start up the motor spinning
it a thousand rpm and then I'm gonna switch off the motor and bring down the tap as it's
it's decelerating and speed start the hole and if it goes too fast I've got the break
this is the break so I can stop it if I need to so we'll see what happens here
so here we go I'm gonna start the motor switch it off and then bring down the tap
okay so I didn't have to use the break and and the tap has started in line with the drill it's
perfectly in line because nothing is moved I'll go grab a tap handle and they'll finish
off the thread and I can just wind it down and I can feel it going through into the bore so
that's it that's our thread and then we've got one more operation in the lathe this is gonna
go up against this and you can see how this is obviously larger than this so what I want to do
I do have a drawing here that I made a bunch of years ago do you see how it it next down
and and it's got a nice radius in here a nice radius so I have to match this size to this so
what I'll do is I'll switch on my vernier I'll put that like that it's just under an inch and
a half and I'll zero it so when I put this in the lathe in the three jaw Chuck when this comes down
to zero I've got the same size as this and then we can work on the ramp that's back in the mill
so switching tools
so if I had a CNC I could I could ramp it down I could ramp it down but I don't have a CNC so
what I'm going to do is a series of little steps every 10 degrees I go down 5,000 and
then I take a file and I file it so that it has to match that taper that's the goal
go so that's that's my zero that I've just just touched so now I go back I go ten degrees and
now I want to go to I want to go to five and then I hit zero I go another 10 degrees
here we go to do that one ramp small multiple steps every 10 degrees how
about manual hacksaw I haven't done manual hacksaw here yet as you come through you
want to be careful because if it if this piece cuts off you wrap your knuckles on
there that's gonna hurt but I stopped at the right time to just break it off that
goes in the scrap bin I'll just go over to the belt sander now take off the birds
back to the belt sander
this is a inte shaft it's just cold roll there's nothing fancy so I'm going to measure it and we're
gonna see what size it is because often these shots are a little bit undersized so now if I
read the dial I'm at 998 so it's point nine nine eight it's 2,000 er one inch and for
reference a human hair is 2004 Ceylon here I'm told is 3,200 inch this is a telescoping gauge
it's also called a snap gauge can you see how it springs if I do that snaps out so I'll push it in
look this is the lock I put it inside I hold it at an angle do you see how it's at an angle and
then I lock it and then I move it over Center and that conforms to the exact size so then I
measure it so I'm at 996 and that's part of the reason why I chose the tube because I knew that
it was slightly undersized so I have to hone it out and the best way to hone it out is this
machine over here we're gonna wander over there what we have here is a Sun and hone it's an old
machine I don't know how old it is 68 years old but they work great if they're in good shape
so I can feel a little bit of pressure in there so I increase this is in thousandths of an inch
yes yeah can you just slipped in my hands
so I'm taking out a couple fowl plus a little bit of it clearance so that it's gonna slide
over here that's what I want so I'm not gonna be measuring but every so often I'm gonna see
okay see how it's starting to go on now it's going on just a little bit I got a drill press
vise here to hold it because it wasn't working very well with my hands and now now we can use
the bar and I can increase pressure so it's gonna be much better we'll see what happens
okay that's a nice fit so I'm going to leave that one like that and we'll work
on the second one I'm starting on a new piece so I have to have to back off on the dial a bit
oh look at that let's try this side this is the side it goes on
oh good that's a pretty nice fit you can see the marks where the old weld was so we'll go over
to the welding bench now we'll just lay a bead down about 1/2 inch and that'll never slide off
this is gonna go against there so after I file down we're gonna use machinist blue
this is what it is it comes in a tube well I have it in a tube and you put a little
smear on one side and then you put the two mating surfaces together and you give it a
little bit of rotation and then that shows you if the blue moves over it shows you
where the high high points are so you see what's happening it's taking off all the
high spots like it should look at that so I'm gonna use some of this machinist blue
you don't need much at all
that's quite a bit
this one an even coating I don't want excess this is kind of like the moment
of truth here so I'm pressing down that it's hitting around there and
it's hitting around there not bad so that's like 60% so if I'm gonna do a little filing
now I'd follow where the blue is and then I'll check it once again so let's see that
you can spend hours doing this to make it perfect but the object is
not really didn't to make it perfect it's just to
just to make it work so there we got it around probably 80% something like that
85% so I'm gonna say that that's good so next step is we'll put this in a frame I
still have that Rocky Mountain frame here and we'll put it on the surface table and
I'll show you how this gets used I have a Rocky Mountain frame it's the one that we
fixed the dent on last week so we're going to check the alignment between the head
tube and the seat tube so this is this is how the head tube holding attachment works
so I lock it and then I pull these apart and because there's the ramp that is locked into
that head - that thing will not move then we have a surface table here we have four blocks
these are just inch by inch cold rolled what right here on the seat tube it's a bulge but
it you can if you take your hand so I take my hand I can feel how it spreads a little
bit so we have to be off the but we have a deckle here we're dealing with and you can
see I don't even have to look you can look there you can see the gap see that so it's slightly
out of alignment it's no reflection on Rocky because who knows what happened to this frame
it's been ding maybe it's been abused but that's basically how it works so if you need to align
it see these here these are called the hooks so you put that goes under the hook like that
and then we put spacer here I'm just gonna grab one more block if I put a block under
here if I put a piece of leather it helps to protect the frame just a little bit and
because the frame is held here can't move if I press down if I press down here I can put
force on the frame anytime you align the frame you have to put forth it's just how you put the
force on that's what makes the difference so put a little bit of force on that you can see
the frame flexing and we'll check the alignment once again so it's out I just have to put more
more force on there see if I need more force I've got this so there I'm definitely putting
some force on there this tube is almost touching the table almost oh look at that
see that tiny little gap there that's actually perfect because what you want to do when you
reline a frame because it's chromoly it's got memory if that's straight and the frames over
here you really want to go a little bit past and then pull it back because then it's gonna stay
there better so we're under the hook I'm gonna give it a little bit of pressure yep that's it
just you saw how much that was you know it's hitting there you go it's sitting right there
there's no gap so the head tube and the seat tube are now in line with each other mission
accomplished thank you for joining us hope to see you next week have a great week stay safe