Could use some insight into machining FDM 3D printed ABS.

[russc]

Just wondering if anyone has experience using say, a lathe to get an accurate surface on a 3d printed part.

here's an example of what I have in mind:

Goal: 3cm diameter cylinder with smooth surface finish, final tolerance +/- 0.05mm.

Procedure:

1. Print 2mm oversize with a decent wall thickness to account for shrinkage and then final surface cut. High infill percentage.

2. Light acetone bath to ensure adhesion.

3. Turn on lathe for final surface.

Thoughts?

[Dirty Engineer]

Interrupted cut on the turned diameter?
How long of part?
Will the part be held in a collet chuck?

Find the sharpest insert you can.
We Sandvik VBMT 331PM 1105 inserts with good results.

[russc]

Let's say a length of 10cm. I'm going to try and get away with running it on a micro lathe (Toyo ml210) so a collet may not be possible. I could print the rough piece with a square base for clamping in a 4 jaw chuck, and support the end with a live center.

Depending on the part, an interrupted cut might be necessary. If the internal features could be added afterwards it wouldn't be worth 3D printing. For example, a bolt air passage.

On the other hand...internal features could be printed, but sealed over with an outer wall, which is drilled out afterwards.

[Simon]

I've not done it myself but a friend who cuts a lot of it says the sharpest tools you can find and high rpm's.

[Jeremy Martin]

What machine are you using to print the part?
I have some bits from Sandvik and crap they were expensive. It may be cheaper to send the first part out to be printed exactly how you would like it by a better machine.

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What machine are you using to print the part?
I have some bits from Sandvik and crap they were expensive. It may be cheaper to send the first part out to be printed exactly how you would like it by a better machine.

[russc]

Thanks Simon.

Jeremy, It's a Mendelmax 1.5 Reprap. Far from an industrial printer, but fairly capable given proper calibration and good filament.

Honestly, from what I'm reading, it's better to just design around loose tolerances and use bearings and captured nuts for anything requiring precise fitment and interaction.

- - - Updated - - -

Thanks Simon.

Jeremy, It's a Mendelmax 1.5 Reprap. Far from an industrial printer, but fairly capable given proper calibration and good filament.

Honestly, from what I'm reading, it's better to just design around loose tolerances and use bearings and captured nuts for anything requiring precise fitment and interaction.

[Jeremy Martin]

I you feel like letting the cat out of the bag you can send me the file and it's not too large I'll print in on a 3D systems 3500 Max HD. It can print to the specs you want.
jmartokc@gmail.com

Simon, how are the parts I printed for you holding up?

- - - Updated - - -

I you feel like letting the cat out of the bag you can send me the file and it's not too large I'll print in on a 3D systems 3500 Max HD. It can print to the specs you want.
jmartokc@gmail.com

Simon, how are the parts I printed for you holding up?

[Simon]

I haven't been using them in actual play, just as templates for design verification and ergonomics.