Does anyone here have the capability to bore/hone the ID of a bronze tube?

[blykins]

I have a piece of bronze tubing, ~24" long, that needs the ID finished to a specific size, +/- .0005". Finished ID needs to be 2.1270".

Anyone here have that capability?

[ALKYAL]

What is the OD size ?

[blykins]

It's tapered in steps....

Big end is 2.313". Small end is 2.247".

[blykins]

BTW, the ID is currently about .015" oversized.

[ALKYAL]

.015 OVERSIZE orUNDERSIZE ID ? Does the ID need to Concentric to the OD ? What is that spec? What is the cocentricity now? The wall is Very Thin now!

[tresi]

I no longer have a lathe but if I were to attempt that I would want to start with raw material and finish the I.D. 1st.

[blykins]

.015 OVERSIZE orUNDERSIZE ID ? Does the ID need to Concentric to the OD ? What is that spec? What is the cocentricity now? The wall is Very Thin now!

Well, let's just say it needs material taken out.

ID needs to be concentric. Don't have a spec and not sure how far it's out now.

Wall should be about .060" thick at this point.

[hoodeng]

If you have a hydraulic ram manufacturer or re-conditioner in proximity to your shop they would be the best equipped to handle your job ,you may need to provide a holding fixture for the tube or weld an extension on one end that can be located into the line hone then cut it off after the machining process.
The steps inside the tube will add a complexity to the job but not that difficult to accommodate.

Cheers.

[SchmidtMotorWorks]

I have a piece of bronze tubing, ~24" long, that needs the ID finished to a specific size, +/- .0005". Finished ID needs to be 2.1270".

Anyone here have that capability?

Very unlikely that you will be able to bore to that diameter and depth ratio accurately.

Probably the most cost effective way to do it will be bore it straight just below the smallest diameter, then use an expandable reamer to do the steps.
You will be lucky to held concentrically closer than a few thousandths over that length.

[Newold1]

I had to do something like this once and I solved the problem by taking a length of 3/8" thick piece of aluminum pipe and boring the inside diameter the same Id as my brass tubes OD. I then heated the aluminum piece to about 250 degrees. slid the brass tube (cold) into it and allowed it to cool to room temp. I then honed out the brass tube to the necessary ID. I then reheated the whole assembly and I was able to push the brass tube out without a lot of pressure while the aluminum tube was still hot. Worked in my case, might work for you?

[modok]

If the bronze is hard enough to hone then you can hone it. due to the wall being so thin it would be best to have a hone with 4 or 6 cutting stones instead of the usual one or two.

If it is very soft then you need to ream it instead, or just expand it by pushing consecutively larger mandrels through it.
That's probably how it was made to start with, whatever it is.

[modok]

It can be line bored. Make clamps to hold it down. That's how cannons were made.
It's so thin it won't be the same size throughout, due to being so thin, but you could finish hone it after that.

It could be bored like a engine cylinder, but the setup would be very difficult. Make an engine block to insert it into then we can bore it

[Nefario]

To modify a tubular part to these specs would be very difficult. To make a new part might be easier.

To make the part I would start with a thick wall tube, make a cutter similar to a gun drill, get close to the 2.127 ID, then hone to the final bore. Heat the brass and install it on a ground rod stock mandrel and turn the tapered OD's.

A self-guiding cutter in the style of a gun drill might follow the existing bore but concentricity won't be held over 24"

If you take the project to a good tool & die shop they can do something like I described to enlarge the hole but if you seriously want these specs and if you have the capability to check it, it could cost $1000+. And yep, I'm sure you'll find someone who'll promise it meets these specs and charges $100.

[Keith Morganstein]

I have a piece of bronze tubing, ~24" long, that needs the ID finished to a specific size, +/- .0005". Finished ID needs to be 2.1270".

Anyone here have that capability?

Im reading this as one I.D. All the way through. If I had a long enough mandrel for the Sunnen bench hone, I would prob try and take the .015” that way, holding the piece by hand, going light and slow, measuring often. It would take a while. The hone will not necessarily produce a perfectly concentric result.

[SchmidtMotorWorks]

It's tapered in steps....

Big end is 2.313". Small end is 2.247".

tt