Hello and welcome to Enots engineering I'm Alan
in today's video we look at the thread dial
we look at the difference between a metric thread dial and an imperial thread dial
we also look at how we can make one using a 3d printer
so let's go into the workshop and see how we do it
so if you have a 3d printer or you know somebody who has
the first thing you need to do is download the program from the website
so we type in thingiverse.com
and in the search box we type in South Bend thread dial
then it should come up with the thread dial and I notice on the right it has a
printed nut for the screw on the top slide
select the thread dial and it'll come up with some more information
on the parts the settings and the program
but this program prints the body in two halves
but if you look lower down in the program details
the part I lighted in blue is another thread dial which has a one part body
and that's what you need to select for the thread dial that I'm using
this is the printout this is for a South Bend lathe Imperial
with a lead screw 8 TPI it will fit the Boxford Imperial lathe
because the Boxford was based on the South Bend
and this is what it looks like
when you've downloaded it from the computer to your printer and printed it out
it looks something like this these are supports to hold the parts in position
while they've been printed so now can break all these off clean it all up
and we're back to just a normal print out which is ready to go
all you need to do is drill the hole out on the side
Fit a metal bar to fit your Boxford
drill a hole through for the spindle fit this on the top of the spindle
and this on the bottom of the spindle and it's virtually ready to go
the top wheel has already got the numbers printed on it and the divisions
the gear is ready to go
so first of all I'll clean this down and we'll come back to it when
I've cleaned all the supports off it
so once you've cleaned it up it should look something like this
on the dial all I've done is put some felt tip pen into the grooves
and sanded the top down to give you the numbers
I haven't done anything to the gear just taken some bits of flash off
and on this i've taken the flash off
that's ready for drilling
So what we have to do on this is ream through here 3/8 of an inch
to support a rod to hold it on to your saddle
and then make a spindle that goes through the holes of gear on the bottom
and the dial on the top
now I know this is for an Imperial lathe and mines metric
what you have to do to assemble this
I'm using an 8mm shaft
so put an 8mm reamer through the hole
make sure it's the right size
I did find out that the day afterwards the plastic had tightened up again and the hole was tight
and all I'm using is a brass rod
Thats 8 millimeters that goes through the center of the plastic
it should turn it doesn't need any bushes or anything like that
because it's only going slow and there's no pressure on it
you have a hole on this side here which I tapped 5mm
but what I should have done was just drilled it clearance of 5mm
and drill a hole in the metal bar that goes in and tap the bar
because the plastic here I don't know if you can see
it's starting to split along the the seams
so if you put a 5mm cap head in there
you put the thread in the bar you're just compressing the plastic
but with the thread in the plastic it's trying to grip the plastic
it depends what plastic you use when you do the 3d print outs
I don't know what plastic this was as my brother printed it out for me
with the gears that go with it
and you need to get yourself or make yourself a 3/8" piece of steel
and that fits into this hole on the end
I drilled this out 3/8 it's nearly there but it's it depends on the plastic you're using
you could put that in and then with the screw that goes through here you lock that
that this part fits into the apron the holes already there
and this is the same if you have a metric lathe or Imperial lathe it's 3/8
so then on the gear put the shaft through the centre
the gear goes on fix the gear through there and then on the top
the same again 8mm reamer through the hole
and on here the holes already there
I would again drill the brass rod tap the rod and just put a grub screw in there
when I assembled this one I just dropped a little washer inside there
so that the two plastic faces are not rubbing there's a spacer there
you need to put the grub screw through on the shaft first
so if you put this on your shaft first measure the depth that you need
put the grub screw in to hold that then you could put the washer on the end feed this through
fit this on and put the grub screw in there to hold that
I would say if you've already got the bars size
so if you already have an 8mm bar and a 3/8 bar
it would probably take you around an hour to finish this off
once you've taken off all the supports and the printing takes about three hours
and that will depend upon the printer settings and speeds and feed you have
when you print the part
drill in tap three holes put two grub screws in this part
a cap head in there and it's finished
so on the saddle it's this hole we use for the thread dial
on the front you have the grub screw and this is a 3/8 hole
if you haven't used it before you might need to put a reamer or clean out the dirt and paint from the hole
and you should find a 3/8 rod would fit in the hole
the thread dial will fit in this hole
I've left the brass bar that's going through the middle full length at the moment
you can see it will pivot on the rod
but that is the finished thread dial
so I'll show you how this works
just pull it across like that to engage it in the lead screw push it forward to disengage it
you have to bear in mind that this is a metric lead screw and this thread dial is an imperial
so every turn is half a tooth out on the lead screw
when you engage the thread dial you can actually tighten the grub screw up here to lock it
this cap here just locks a 3/8 rod to the plastic
when you're cutting a thread once you've engaged the dial keep it engaged until you finish cutting the thread
Now for the Boxford metric lathe there are two main differences
one is the dial looks like this
and the other differences are it had two gears one with a 20 tooth and one with a 21 tooth
if you look on the internet you can find the Boxford chart that tells you
which gear to use for the pitch that your cutting
so the chart shows you the thread pitch on the left
the gear you should use one or two
and then the position you can start cutting a thread
all of them are in A and then you have
the option of B C D or E
oh well that's it for today I hope that was interesting
hope you enjoyed it look after yourself and we'll see you next time
On Enots engineering