[duncsuss]

I just got one of the Kelton McNaughton bowl core saver gizzmos, and naturally had to try it out right away ...

I can report that it works -- the core was indeed saved. Unfortunately the part that was supposed to be a "bowl" from around the central core has more in common with a funnel than a bowl ... ooops ... :huh:

 

[Dave Paine]

I know THAT feeling. :sad::sad:

I will post more information later on my learnings.

My Kel M. system is used and I think one knife has a flat spot.

I have cored a few bowls, one went through, one almost went through and some were as planned.

I have come up the learning curve on how to set the knife.

Interesting that you use the left side of the rear post. I use the right. I have no idea whether this makes a difference.

 

[duncsuss]

All advice & information gratefully received ... :yes:

I hadn't even thought about which side of the center divide I chose -- it just seemed to happen that way. I guess rubbing the round peg against the flat side of the knife is more natural to me than having a flat rubbing against a flat. Less friction, or sumpn.

 

[Travico]

The bowl can sill be saved! Just turn a plug/patch for the bottom of the bowl and glue it in. You may even be able to turn a pedestal for the bowl and plug the hole with it.

 

[Dave Paine]

Continuing with my personal learning on the Kel M coring system.

If you have not watch the Dale Bonertz video on using this system, I recommend you watch now. He is very experienced user.

https://www.youtube.com/watch?v=mS2yIb0HAU4

The part I had trouble with was replicating his method to position the knife.

I placed the knife over the bowl, but I had a difficult time tracing the curve back "in the air".

My solution was to make a half circle template for each knife. In theory each knife is a part circle. I used a compass on paper to determine the actual circle for e.g., the outer circumference.

I then draw a half circle on a piece of card. I cut out the half circle keeping the outside pen mark. I also drew a line to represent the inside edge and the 90 deg mark.



I cut grooves in the face of the blank to represent the cores I want to make. I find it is easier to enter the knife in the blank when there is a groove. The actual groove also helps in positioning the knife.

This picture was taken after removing the first core, but shows the groove for the second core. I made the grooves prior to positioning the knife. Dale uses pencil marks. The grooves are easier to see for knife positioning.



In the above picture you will note a piece of PVC pipe. I cut this to exact length so that the knife cutting edge will be at exactly top dead centre. No need to measure, just install the turret and piece of PVC and good to go.

I mark top dead centre on the bowl blank and lock my headstock.

Positioning the knife was a two person operation. One person had to hold the knife and the other to sight down the face of the blank.

I made a simple jig to hold the knife in position. Clamps to the lathe bed.

Front picture. Made from scraps. I needed a wider top support and the wider scrap was not deep enough, so I attached this to the vertical portion with bolt and barrel nut.



Rear picture. Vertical portion is glued to horizontal portion. I cut a piece to fit in the underside of the lathe bed and use a carriage bolt with a simple knob on the top.



This works well. The knife is actually at a slight angle. I can move the support front to back to meet the desired angle.

Now I can have the knife supported while I sight the angle when working by myself.

I leave the support in place for use, just to make sure I do not allow the knife handle to drop which would not be good if the knife in the core were to go above centre.

I use the template with the diameter parallel to the top dead centre position and the outer edge of the template at the outside of the relevant groove. A quarter of the circle over the bowl blank and a quarter of a circle over the knife - once it is positioned in the groove.

I hope this makes sense as you read.

I have observed that my friend and I find it easier to go too deep, so do not worry about repositioning the knife during the cut to make a tighter radius - it may be needed.

Let me know if I need to clarify any details.

 

[cuerodoc]

Ahhh, been there and have done that. See if you can use view the video by Mike Mahoney on using the system. Helped me.
Now I try to "visualize" knife as it's going through. Be warned the video makes it look "too" easy--plus I don't think he used anything near as hard a wood as I use.
C'mon over---we can have a beer (or three) and watch it.

 

[duncsuss]

The bowl can sill be saved! Just turn a plug/patch for the bottom of the bowl and glue it in. You may even be able to turn a pedestal for the bowl and plug the hole with it.

Thanks ... yes, I've been thinking about different ways of patching it (and maybe even making it look like I intended it to be this way :shifty

 

[duncsuss]

Continuing with my personal learning on the Kel M coring system.
...
Let me know if I need to clarify any details.

Thanks Dave - lots to digest here, I'll read it a few times and try to understand it before hocking you with questions. Appreciate you gathering all this information.

 

[duncsuss]

Ahhh, been there and have done that. See if you can use view the video by Mike Mahoney on using the system. Helped me.
Now I try to "visualize" knife as it's going through. Be warned the video makes it look "too" easy--plus I don't think he used anything near as hard a wood as I use.
C'mon over---we can have a beer (or three) and watch it.

Thanks -- I've heard about Mahoney's video but haven't seen it. Besides, who the heck watches a how-to before trying out a new tool? :laughing: