Anyone ever mill a material called Bun

[Todd Mann from Fastech]

We have some material called Bun. P/N is R-310-V.

We are trying to drill and mill it. Does anyone have any suggestions?

[Todd Tracey from Fastech]

Morning Todd, haven't cut it but I've seen some nice BUNS

[cadcam]

Well at least he didnt ask if anyone has Drilled some BUNS Sorry could not help my self.

[Guest]

At least there weren't sticky buns involved

 

[LaszloK]

That is a foam rubber. "Bun" refers to the typical stock condition. Buns are usually "skived" to the desired thickness. I don't have any eperience with this particular foam, but it us usually best machined with a waterjet machining process.

 

 

PRESS MOLDED BUNS

 

PHYSICAL PROPERTIES

 

 

Type R-310-V/R-326-V

Polymer PVC/NBR

Color Buff / Gray

ASTM D-1056-67 Classification SBE-42

ASTM D-1056-00 Classification

Suffix Requirements 2B 2

B2, C1, M

25% Compression Resistance1 (psi) 5 - 9

50% Compression Set2 (%) 25

Density3 (lbs/ft3) 5 - 10

Water Absorption4 (lbs/ft2) 0.1 max.

Tensile5 (psi) 90 min.

Elongation6 (%) 175 min.

Flammability7 - FMVSS302 Pass

FAR 25.853 Pass - 1/8" min.

Standard Sheet Size (in.) +/- 3% 40"x 56"

Expected Yield (in.) 01.25"

From full bun-thickness-based on 2 level cuts

125% Compression Resistance..........ASTM D-1056

2 50% Compression Set....................ASTM D-1056

3 Density........................................ASTM D-1056

4 Water Absorption..........................ASTM D-1667a

5 Tensile........................................ASTM D-412

6 Elongation...................................ASTM D-412

7 Flammability - This item and any corresponding data refer to typical performance in the specific test indicated and should not be construed to imply this material's behavior in other fire conditions.

Other gauges and widths may be available. Please refer to Customer Service.

 

Note: SAEJ 18 is equivalent to ASTM D-1056.

Issued : 10/01/04

[Colin Gilchrist]

You can also "freeze" these parts in Dry Ice and them machine them while they are hard. You have to watch for part expansion when they heat back up to room temperature though. Sometimes the rate of thermal expansion can be calculated and you can cut your parts slightly undersize to make them nominal when they warm back up.

 

HTH,

[kinglouie V]

quote:

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PRESS MOLDED BUNS

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[Todd Mann from Fastech]

Thanks everyone we are making some head way. For drilling we used a speed bore bit and a brad piont bit like you woulr drill wood with. They worked great! For milling we are using a 1/8 double cut carbide burring tool running as fast as the old machine will run, and cutting the out side then milling the middle out. Seem to be working so far.