Resizing Tool for Aluminum Round Rod

[bretthl]

Have you looked into having the stock centerless ground?

I have not, I will though.

 

[MrWhoopee]

Here's a roller box turning tool

 

[RJSakowski]

I have a bunch of pieces to make from 1/2" diameter aluminum round rod. The rod must be sized to 0.495" +/1 0.002" in short sections. I have been doing this on the lathe but it is tedious work. Does anyone know of a tool that can be adjusted, run in the tail stock and over-ream to the required dimension? I have seen adjustable reamers for holes and am hoping such a tool exists that will work on the OD of round stock.

Here is what I would do. I would set up my carriage stop on the bed and make a suitable spacer. For a tool, I would use my parting tool. For a cutting depth of .0025" on aluminum, it will work for facing, turning and parting.

With the spacer in place, I would advance the stock to allow for a facing cut. Then I would remover the spacer and turn the o.d. to the stop where I would part off the piece. Advance the stock and repeat. It's fast and with care can easily meet your specs for length and o.d.

If finish on the face and/or part length is a concern, you can use a second op for facing the ends. A spindle stop will make that task easier. For facing, chuck runout won't be an issue so the three jaw chuck can be used.

I have used variations on this process many times for quickly making multiple parts.

 

[bretthl]

Here is what I would do. I would set up my carriage stop on the bed and make a suitable spacer. For a tool, I would use my parting tool. For a cutting depth of .0025" on aluminum, it will work for facing, turning and parting.

With the spacer in place, I would advance the stock to allow for a facing cut. Then I would remover the spacer and turn the o.d. to the stop where I would part off the piece. Advance the stock and repeat. It's fast and with care can easily meet your specs for length and o.d.

If finish on the face and/or part length is a concern, you can use a second op for facing the ends. A spindle stop will make that task easier. For facing, chuck runout won't be an issue so the three jaw chuck can be used.

I have used variations on this process many times for quickly making multiple parts.

Thank you. I will definitely try your method. I had no idea you could use a parting tool for light turning cuts, makes sense though. I just wasted 50USD on Janderso's new tool (but I am intrigued to get it working).

 

[Flyinfool]

A Quick Change Tool Post would make the process a lot easier and faster and repeatable for the tool change operations.

If you use the parting tool for turning and facing, make sure that the hole is drilled first and the the parting tool has absolute minimum stick out, or it will deflect with side loads. You may also need to use a thicker parting tool if you get to much flex.

 

[NC Rick]

Here's a roller box turning tool

Way back, I ran a turret lathe for most of a week (before quitting that job). I was too young and inexperienced to do anything but pull the handles.
id like to add a question which I hope is relevant: if a guy like me (who is fresh out of Box Tools) had a follow rest, can this be setup in a similar fashion and be useful to the original question in this thread? I have a follow rest with my lathe but in all my days, have never used one.

 

[Flyinfool]

A follow rest to turn the longest bar that your machine can take was my first thought.

 

[MrWhoopee]

if a guy like me (who is fresh out of Box Tools) had a follow rest, can this be setup in a similar fashion and be useful to the original question in this thread? I have a follow rest with my lathe but in all my days, have never used one.

Yes. The biggest differences are the distance between the rollers and cutting tool and a follower rest runs on the finished diameter instead of original diameter. I've only used a follower rest a couple of times, but they can be very finicky. Mounting a cutting tool directly on the follower rest might work out.

 

[RJSakowski]

If I wanted your bored hole to be concentric with the o.d., I will want to bore on the same setup that I turn. This precludes turning a long length, parting , and facing unless you have an accurate collet chuck. In my previous process, I would add the boring step after the the facing step. It is still only a single setup process.

One of the parts that I made in quantity was a small Delrin cap. machining tolerance were +/- .001"


The cap was made on an Atlas/Craftsman 618 with a single tool, a small boring bar made from a broken tap, and a .020" carbide drill bit in the tailstock. I used a carriage stop and several pins as spacers for determining the z position. The stock material was 1/4" Delrin rod. The tool was set up for boring at a slight angle to the spindle axis.

The first operation was to face the part. The second was to bore the pocket. Then the .020" hole was drilled. To turn the o.d., I reversed the lathe and turned with the boring tool from the back side of the part. To part the piece, I used a box cutter, leaving an excess for a final facing.

For final facing, I made a small mandrel with a press fit for the cap. The carriage stop was used to determine the cut and the same micro boring bar was used for the tool. The dome was finished was a fine file as its profile was not critical as long as the central portion was the high point on the face.

Total setup time was less than 10 minutes. Once the setup was done, no further measurements were necessary until final inspection. These parts only took a few minutes each to make.

 

[NC Rick]

Yes. The biggest differences are the distance between the rollers and cutting tool and a follower rest runs on the finished diameter instead of original diameter. I've only used a follower rest a couple of times, but they can be very finicky. Mounting a cutting tool directly on the follower rest might work out.

I'm going to have to play with my follow rest. This was of interest to me as the fellow used the compound to offset the cutting tool so the follow rest runs on the machined surface. Some of this stuff can be rather thought provoking. Which I enjoy even if I never use it.