Bulldog/Dublin on an undersized lathe

[DocAitch]

Cutting the top of a bulldog and the accent rings on a small lathe presents a challenge. There is not enough swing on my HF 8x12” metal lathe to use the traditional methods- pipe jaws (don’t have them on my 3 jaw chuck) or jam chuck working from the left (because the shank will not clear the saddle/tool post)
Below is presented a hybrid method- freehand approximation and then refinement on the lathe.

1) Determine the geometric elements of the shape.


2) approximate the shape freehand while cutting for grain and avoiding flaws.
a. The base cone is approximated along the rays of the grain


b. The shank begins to form-angled to avoid flaws.

c. The top cone is approximated and the diamond shank begins to develop.


3) After freehand drilling using a modified freehand method, a “drive dowel” is attached to the stummel coaxial to the chamber. This will allow the stummel to be driven from the left and cut from the right while clearing the lathe bed

a. Diagram of drive dowel/stummel

b. An alignment dowel has been cut to fit coaxially in the chamber. The upper end is reduced to fit the quill chuck of the drill press

c. The drive dowel (trued and center drilled) is aligned on the drill press jig using the engagement pin of the jig and a pin chucked in the drill press.

d. Some melted thermo plastic is placed on top of the drive dowel and the alignment dowel/stummel lowered onto the melted plastic and held there until solid (2 minutes). I use a bungee to hold this down and do something else.
The photo below is of the assembly after turning. A turned and center drilled piece of Delrin has replaced the alignment dowel. This engages the live center of the tail stock.


4) The drive dowel is chucked in on the left, the Delrin plug is engaged with the live center, and the top of the bowl and accent rings are cut on the lathe. I used the “etch-a-sketch” method and my regular cutters for this, with some smoothing with files.

The accent rings were cut with the tool at the bottom of the photo. This was ground from a stock HSS tool.


5) When finished turning, the drive dowel and thermoplastic are broken loose from the stummel. This was a very strong bond- I could have used about 1/3rd as much plastic. I had to clamp the. dowel in the vise and partially cut the plastic with a hammer and chisel.


6) The stem rod is fitted and shaped along with the shank- rotating 90 degrees to achieve a symmetrical diamond.


7) Finished Bulldog/Dublin I did put a small (2mm) bend in the stem.





DocAitch

[DocAitch]

This construction of the drive dowel/stummel can be done directly on the lathe without using my drill press jig. Just take care not to have the plastic drip off or the construct sag.
DocAitch

[Ocelot55]

Walt, you always come up with the most creative jigs and methods to solve your problems. Highly entertaining. I probably would have just thrown up my hands in surrender and ordered more equipment.

[DocAitch]

it probably would be easier with an unlimited budget, but I do feel that this method allows me to fuse the freehand/shape first method and lathe turning with a $750 lathe, a cheap three jaw chuck and a $200 drill press (both were on sale at HF).
I am pleased with the way this one turned out.
That thermo plastic is the s**ts-
DocAitch

[caskwith]

Another way to skin a cat. Nicely done.

I have used similar methods to also get around the problem of a small lathe, amazing what you can achieve with some scrap wood, some glue and a little forethought.

[brownleafbeardsman]

That jig you made for drilling stummels after shaping is genius!
Nice Bulldog, Walt!

[DocAitch]

A couple of more photos.
The first demonstrates the lack of clearance over the lathe saddle when the stummel is placed on a jam chuck.

The second shows a much simplified way of attaching the drive dowel. There is no need to true or center the dowel (although this one is center drilled). Simply place the dowel in the lathe chuck and use the tail stock chuck to hold the alignment dowel and stummel. I used a lot less plastic this time.


The alignment dowel is then removed and replaced by the Delrin piece to engage the live center without removing the drive dowel/stummel construct from the lathe. You can begin turning immediately.

DocAitch

[Sasquatch]

Dear Walt, what the fuck are you doing?

Hope this helps
Todd

[LatakiaLover]

https://en.wikipedia.org/wiki/N-dimensi ... ove_puzzle

[seamonster]

Dear Walt, what the fuck are you doing?

Hope this helps
Todd

Ha! Playing the classic hits....

[linearone]

Can I make a suggestion? You can buy an expanding internal mandrel in a size to fit the chamber. Beall makes them.
Then you can chuck it in the 3jaw you have there or a drill chuck mounted on the spindle.it holds very securely. It's what I use to cut my beadlines after blasting.

[DocAitch]

The problem is that with my lathe, when you do that the saddle is under the stummel, and you cut from the left.
If you look at the 1st photo in the second set, you can see the shank will not clear the saddle/tool post.
A Senior reamer works well as an expanding internal mandrel.
DocAitch

[caskwith]

The problem is that with my lathe, when you do that the saddle is under the stummel, and you cut from the left.
If you look at the 1st photo in the second set, you can see the shank will not clear the saddle/tool post.
A Senior reamer works well as an expanding internal mandrel.
DocAitch

Same problem on my lathe.

[linearone]

Ok, now I get it

[JMG]

Walt...I want to see a cartoon movie of your thought process. Like one of those old school, black and white, fantasia'esque style cartoons. And, while I've never done drugs, I think this will be best viewed while consuming drugs.

[LatakiaLover]

Walt...I want to see a cartoon movie of your thought process. Like one of those old school, black and white, fantasia'esque style cartoons. And, while I've never done drugs, I think this will be best viewed while consuming drugs.

Ask and ye shall receive:

https://www.youtube.com/watch?v=8n0J2c1 ... ex=8&t=87s

[DocAitch]

Walt...I want to see a cartoon movie of your thought process. Like one of those old school, black and white, fantasia'esque style cartoons. And, while I've never done drugs, I think this will be best viewed while consuming drugs.

John Michael, I am not clear on your thought process. Did you read the whole sequence?
I wanted to make a bulldog family pipe and have a 8x12” HF lathe with the stock 3 jaw chuck and a 13” HF drill press -total cost <$1000 for major machinery.
This is how I did it and the pipe came out pretty well.
It’s not perfect (lost the line a bit at the top of the shank at the transition and the stem is a little wavy in front of the button), but I think it is a pretty good pipe, which combines the shape first process (for briar figure and avoidance of flaws) and the precision of lathe work for the top and accent cuts.
I will admit that the first drive dowel attachment was a little cumbersome, but I presented a better way in the follow up sequence.
I published the sequence to show some of the guys who are using small lathes that this is possible.
Please tell me how any of this is bizarre.
DocAitch

[LatakiaLover]

He's just giving you a bit of le shitte, because retired ER docs are fun to mess with.

(Almost as much fun as pipemakers who live in Cornwall)

[caskwith]

It's not bloody Cornwall, you are as bad as Neill Rowan!

[LatakiaLover]

OK, we'll split the difference and say it's Bodmin.