Turned leg

[rhfurniture]

Hi, I have to make 120 of the leg drawn below in Brazilian (note the kicked out foot)
Can anyone with an indexer tell me:
1. If this could be done well and easily
2. If they are in UK (or close eu) would they quote for turning (I supply blanks).
3. If there is anyone who would sell me a prt indexer so I can play with it myself (there is potential for repeats).

R.

4785

[marshawk]

Hi RH,

They can be done on the indexer with some minor, manual cleanup work, but you may waste a few blanks until you are satisfied with the spindle.

The first thing that I see is that some of the turnout on the bottom will have to be shaped by hand. The reason for this is that the blank has to spin on the center axis so an "extension" needs to be programmed forward of the bottom of the leg.

If you imagine a straight cylinder running through the center of the blank - top to bottom - you can picture what the bottom of the leg would look like.

I would be happy to help you with the design when you get to that point. I would be happy to make the spindles for you, but I think the export taxes would be prohibitive.

Please let me know how I can help.

Cheers!

Chip

[rhfurniture]

Chip, hi.
Are you saying that I need a solid cylinder of material from one center to another, or could I interupt it, by using a blank that went 50mm below the bottom of the leg?
My plan B is to get it turned on a regular lathe down to say 5mm below the bottom bead, then use Millwizard to 3dcarve and finish by hand, But if I can do it better by indexer, would love to give it a go.
Shame about the Atlantic.

Thanks, Ralph.

[rhfurniture]

PS: I've just checked the drawing, and the bottom of the flair is only 1.5mm away from the centerline.

[stevem]

I’ve never used an indexer, but it seems to me that the centre axis of the part can be moved to any convenient spot and the software will take care of the rest. Since the speed of rotation is very slow, there is no need for the stock to be balanced.

Is this correct?

[marshawk]

If programmed correctly you will have just a 1/2" nub sticking out at the bottom. Easy to cut off and sand down. You would want at least 1/2" for strength and stability while it is being turned.

It may be easier to do it on the lathe and hand finish... They will take about a day apiece to do on the indexer.

Chip

[marshawk]

Steve,

You can do that, but you end up with some abberations in the design if not done linearly (Linearly?.. You know what I mean..)

You also get some substantial variance in cutting height if you do it that way. We have been down this road before and it's much harder to get a decent looking design if tilted.

Chip

[gerald_d]

How do guys make axe-handles? I guess someone with an "axe handle turner" (?) will be able to make them for you?

[marshawk]

I make an axe handle by buying the axe with it attached. That way I don't have to get all of that silly sawdust all over the place...

[bill.young]

If someone with an Indexer ends up working with Ralph on this, send me an email...I may be able to help with the offcenter turning on the foot.

Bill

[stevedavidpotter]

If you need help with this we are in UK and do this type of stuff all the time

[gerald_d]

Welcome Steve. It's great when someone's very first post is an offer to help! Ralph is in Cheltenham, about 200 miles from you.

[hespj]

I wanted a bit of indexer practice, so I had a go at cutting one of these using Ralph's geometry.


4786

I certainly learned a lot about 4th axis software and 4th axis cutting.

I found the wood difficult to hold in the indexer chuck, and the square section at the top of the leg shows this - the wood didn't always turn the same amount as the chuck. I need to look into this. The problem is partly because the stock centreline was not on the indexer CL. My first attempt at holding it in the chuck was done by screwing a disc of metal to the end of the stock and grabbing this in the chuck, but this slipped in the chuck jaws. My second atttempt used the screw in attachment supplied with the indexer, but this is really designed for use with a lathe which rotates in one direction, and tended to come unscrewed when the indexer was rotating "backwards".

I had arranged that the CL of the part was all in solid wood (the "foot" of the leg kicks out"), but even so, the software RhinoCam didn't like cutting to near the CL and left material that needed removing at the foot. I guess it's not usual to mill right down to the CL as there would be nothing left; however an assymetric item such as this does have wood left, and I need to find a workaround for this problem.

Otherwise it worked well. Took about 3hrs to cut, but could have done with better finishing cuts, but poor finish is also due to small diameter at foot end (5/8") allowing vibration. Anyway, Ralph found a more cost effective way of getting it cut.

[rhfurniture]

Thanks for all the energy,

R.

[jhicks]

John, on the subject of mounting the stock for a forward and reverse rotation, you might find the "index Hubs" used on the legacy machine helpful.
http://www.legacywoodworking.com/
They are $3.50/ ea and mount to the standard legacy
A hub is mounted on the end of the stock when turning between centers using Legacy's standard Index Drive Center.
I didnt see a photo of the "drive center" but I am sure if you e-mail or call them they will help you determine if this will work.

[hespj]

Thanks Jerry. I'll see if I can work out how those work.

[waynelocke]

Ditto the Legacy mounts. They work great.