Dividing head

[mattinker]

VT and PekkaNF,

I cannot for the life of me remember why I did it that way!  The bolts in question have flat heads.





Looking at the tool again, having all three heads on the same side would have made it more difficult to use. As you can see, I cut a screwdriver slot in the adjusting screw. I don't think I thought about it at the time, but I used M6 bolts, these have a 1mm thread. 1 turn = 1 mm I don't remember what the Gingery on looked like, I lost the lathe book when I moved here. A useful little tool, I don't think it was responsible for my mistake!!

Thanks for your comments, regards, Matthew

[vtsteam]

Now that you mention it Matt, I started to wonder how mine worked with three bolt heads together like that! Dug around and found a photo -- turns out it was only two bolts. Those and a piece of bent strap, and a piece of square keystock, per Gingery. Two screws and you've got a gauge capable of easily adjusting a boring cutter by a thousandth of an inch. Or less if you have shim stock that thin. Always so simple. Here's the pic:

[mattinker]

VT,

two bolts. I don't know why I added the third. I also added lock nuts, I suppose I was afraid it might unscrew when taking out the feeler gauge!

Thanks for your thoughts, regards, Matthew

[vtsteam]

Lock nuts definitely good idea -- on mine they are on top, out of the picture against the bolt heads. They would be screwed down against the block of key stock when making an adjustment.

I like yours just as well -- it shows the same principle can be used in lots of ways -- and your memory of the book was really sharp. Enough to work out an equivalent tool with what was on hand. I think that's the real value of those books -- gives you a feel for solutions to problems with very simple materials and means, by intuition. Gingery kick started people into their own capability. He did for me anyway.

[mattinker]

Hi,

you give my memory far too much credit! I made the gauge over ten years ago. I got into casting through Gingery although I didn't build the series, I made lots of pulleys, sacrificial face plates, machine handles, various parts and a dividing head using a 100/1 worm gear it's big and cumbersome and 100 to 1 is not very practical. I think this gear type dividing head is far more suited to my temperament.

regards, Matthew

[mattinker]

Now that I've established that the diameter of the spindle is final it's time to make the chuck mounting.




I found this drawing on the web sometime ago, I don't know where I got it from, there was no signature. If it's a no no, I'll take it down with pleasure! I thought it might be usefull to somebody that has a Compact 8



To get a rough position for the top-slide, I G clamped a piece of 15mm x 15mm cold rolled to the side of the top-slide, and wound in the cross-slide. I couldn't see any light between the cone and the CRS.



The method for finally setting the topslide came from John, Double Boost. The bolts holding the top-slide are nipped up lightly, the dial gauge is mounted to the top-slide at centre height, the top-slide is bumped gently to adjust.



I got to within 1/100 of a millimetre, which I decided would be OK to start.



I should have roughed it out on the Colchester, there was quite a lot to take off!



Some time later.



Getting nearer!



Close enough to start bluing! "Muppet", it is easier if you blue the chuck rather than the shaft, that way you take off the blue and not where the blue isn't!



My lathe is new, as you can see it cuts towards the spindle centre using the cross-slide.



Delicately, a bit at a time.



I have a little shoulder to remove from the corner.



I recessed the shoulder.



Closer!





Ooops! I'd deliberately left it thick at large diameter to allow for taking too much of the cone!



I'm not going to show you all the bluing, it's too monotonous!



Now we're getting somewhere!







The finish is better than it looks! A clean up with emery-cloth, coarse and fine,



Knocking of the sharp bits.

That's it for tonight, regards, Matthew

[mattinker]

Hi,

The split cotter.



The cotter is removed from the bore.



Cut in two.



A piece of 18mm CRS round is chucked up, trued up and faced off.



Centre bored.



Drilled 5mm and tapped M6



Sawn off, I still haven't got around to making a parting tool holder!



Faced off and the corners chamfered.



The addition of a suitable piece of threaded bar. I'm out of 6mm round or a suitable bolt to make a "proper" stud!



I have neither an Ebonite ball as per the instructions, nor a ball turning attachment but I do have a ball bearing that I've softened by putting it in the barbecue (heating red hot) and leaving it to cool slowly in the ashes.



Turning a small flat on the ball.



Centre drilling.



Drill 5mm tapping size for 6mm.



As the hole is short, I ground the point off a machine tap to make it a bottoming tap.



Tapping the ball.



Tapped!



As I haven't got any 6mm round, I used a piece of 7mm, turning it down to 6mm and chamfering the end.



Threading with a 6mm die. I had forgotten just how worn that die is, I had to put it on backwards to finish the thread.



Not a pretty sight, but it should hold the ball!



The other end I threaded 7mm, a size that isn't common even hear in the heart of Metric France! Bad planning, I could have done both ends 7mms!



Cleaned up ready to install.



With the split cotter now in place, the "closer" is screwed in and tightened by hand to establish where the position of the lever. Marked with a scribe.





A 7mm flat is milled on the side. Kieth Fenner demonstrates this method in his Shafting video (youtube). When the milled surface is square, you "eyeball" the milling tool so that it's in the centre.



Centre drilled.



Drilled 6mm, Tapped M7.





The completed split cotter and it's handle.

That's it for now , regards, Matthew

[vtsteam]

Looking good Matt! 

[krv3000]

thats cuming on nice a bit of topic have you got the travalnshons ofing stedy for your lathe if so can you do a diagram ofit so i can mack one for my lath

[mattinker]

thats cuming on nice a bit of topic have you got the travalnshons ofing stedy for your lathe if so can you do a diagram ofit so i can mack one for my lath

Thanks KRV. Sorry, I can't help with either kind of steady for your lathe.
Regards, Matthew

[mattinker]

Looking good Matt! 

Thanks VT! It's good for the morale!

Regards, Matthew

[mattinker]

thats cuming on nice a bit of topic have you got the travalnshons ofing stedy for your lathe if so can you do a diagram ofit so i can mack one for my lath

Thanks KRV. Sorry, I can't help with either kind of steady for your lathe.
Regards, Matthew

Hi KRV, I came across the parts manual for the compact 8 pages 22 and 23 are traveling steady and fixed steady. I hope this is of some use!

Regards, Matthew

[mattinker]

Hi,

to finish off the ends of the body casting, I turned the work round in the lathe to fly cut the other end.



Set up.





Finished. Now, both of the ends of the bore are square with the bore which will enable me to put it between centres on the Colchester to tun down the recess for the banjo, surface the banjo end face.

I want to see how the casting for the banjo is. There are signs of slight pitting.



Setting up to face one edge.



Taking the top off.



Having skimmed both sides, the work will sit nicely in the vices.



My mill is slightly out of tram, not enough to be a problem here. As I'm going to rotate the head later, its not worth adjusting it now.



Having skimmed the other side, I set up the work on a round bar and got it as straight as I could between the trued sides.



A true face.



Turned back over, on parallels to bring the first face into parallel with the second.



In order to layout the position of the hole on the Banjo, I started by bluing it with marking fluid and measuring it with my height gauge.



I missed a photo of drawing the line with the height gauge. The gauge was adjusted to half the height and I scribed a line with it along the centre. Using the dividers I scribed the largest circle I could get into the piece of work.



Centring the the part to the middle of the future bore.



The same old boring process. Centre drilling.



A biggish pilot drill.



More drilling!



Again!



43mm! I'm roughly 2mm off final dimension.



I wanted to see how deep the pitting was. I think it's superficial and a lot of it will go with the final bore.



Between centres, I turned a shouldered piece of large round in the four-jaw and then turned a cone on it. As you can see, I tried it as it was , it worked, but a dog was in order.



Dogged!



The Colchester is bolted on to a concrete riser block, no movement or vibration!



Squaring up the front edge of the base and beginning to turn down for the banjo seat.



More of the same, I liked the photo!

That's as far as I've got for the moment! To be continued.
Regards, Matthew.

[tom osselton]

Looking good mind you I would be standing out of the line of fire if those c clamps let go!

[mattinker]

Tom,

Thanks Tom. I was well out of the way!

Regards, Matthew

[NeoTech]

When i see solutions like this i always realize..  Safety is really subjective and you can get away many times with setups that makes gray hair grow on younger machinists that just got out of school..     

[Mayhem]

Nice work Matthew, those last pics look like fun...

[vtsteam]

When i see solutions like this i always realize..  Safety is really subjective and you can get away many times with setups that makes gray hair grow on younger machinists that just got out of school..     

Too late for me! And I ain't dying it black.

I like a faceplate and angle iron, bolted part, and a counterweight because that's what I started out with. But if I didn't have those, I'd probably cob something up. So, guilty, but gray, too!

[vtsteam]

Just realized there may be some idiom trouble in my last statement -- on this side of the pond (and in this state at least) the word cob is the equivalent and shortened form of "to cobble."

[mattinker]

Mayhem,

it was fun!!

Neotech,

there's very little force exerted on those "G" clamps, they are cheepo, which means that the surface of the clamp is rough and tends to bite in!
They are 2", 50mm clamps so they don't weigh much!! As for the white hair, I couldn't get any whiter!!

VT,

it goes between centres, so I could have drilled two holes in a piece of flat bar and bolted it on but, "getter done!" Idioms with explanations, this forum is a great place for an ever expanding vocabulary!

Regards, Matthew

[doubleboost]

Coming along very well
John

[mattinker]

Thanks John, I'm enjoying it, I just hope that I can keep on having time to do it!

Regards, Matthew

[krv3000]

hi its shaping up nice thanks for the hellp regarding the stedys i have the parts manuwel but it gives no dimenchons i will just have to figer them out

[mattinker]

KRV,

the only critical dimensions for the fixed steady are centre height and the "foot" where it sits on the bed. Even these aren't that critical as the adjustment in the three finger can compensate!

Thanks for the encouragement on the dividing head!

Regards, Matthew

[mattinker]

Hi,

I just had to upgrade photobucket, I was over the 100Giga /month bandwidth. I hope nobody was inconvenienced by this!

Back to turning down the "nose" of the main casting.



For those of you who see me as dicing with death, The casting is between centres, it's running at around 150rpm, so the loads on those two "G" clamps is pretty low. Fortunately it's not running in a division of 50 hertz so it looks like it's spinning although I can't really see it clearly! Mind your fingers!





I'm using a form tool to cut a radius in the corner of the nose, the tool itself is difficult to see.



Beginning the cut on the shoulder where the banjo sits.



More shoulder!



I don't have any dials on this lathe, I prefer using a "clock" it's "what you see is what you get", at least, as far as the radius is concerned!



Getting close! I see that I didn't take any photos of measuring with the mike!



I do like action shots.



45° tool, taking of the sharp corners, hmm, it's a bit hard to see!



At least I got this one right! Now I can go back to the banjo.



Centring the bore.



First cut.



This is an imperial boring head, I find it easier to use a dial gauge to adjust, nice big dial, instead of a tiny little thing in thousands of an inch!



I bought this bore gauge set for this job, a cheepo that I had to smooth the ridges of the ends before it would work properly.



A nice sliding fit!



One of the nice things about this milling machine is you can also use it horizontally. Finding the centre of the thickness of the banjo.



Finding the top to place the hole for the pinch bolt.



The usual suspects, centre bore.



Muppet! I had to centre bore twice, I forgot to deduct the 5mm radius of the centre finder!



Drill, 6.75mm right through, tapping size for 8mm.



Drill half way through, 8mm clearance.



I had to tap with an adjustable spanner, I don't trust my self to power tap and you can't just switch off and let it run through, there's a serious very efficient spindle brake.



I didn't measure the cutter, a second hand one, beautifully sharp, 1mm under the 19mm marked on it!



The next on up is 22mm so I had to lift it to take the corners off as well.



I have three of these arbours, by the paint marks on them one of them is bent! They're 25.4mm the French don't know that they're using inches on some of their tooling!



2mm slitting saw.





It works!

That's it for now, be back soon, regards, Matthew