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Minor Profile change

PostPosted: Fri May 04, 2012 12:41 am
by bdring
The MakerSlide profile is going to change slightly in the future. The old profile was proving difficult to extrude. There were material flow issues centered around unslotted portion of the face of the profile. While the critical v groove features were not affected, the old profile had some issues.

The unslotted section tended to droop a little and not be perfectly straight. It also was inconsistent in thickness. It gave the appearance that the extrusion was warped in that plane.
1. Some of the angular webs were not the full thickness they should be in that area.
2. As a result the material was being extruded in an easier to extrude alloy of 6063-T6.

The new profile removes one web which will significantly improve the support of the extrusion tool insert that creates the void and improves the material flow in that area. The new profile will be extruded in a more structural alloy of 6105-T5.

I believe this will result in a small net gain in rigidity. The critical parameters are Area Moment of Inertia and tensile strength and Modulus of Elasticity. The cross section values are calculated. In reality, less than the full cross sectional area was present in the current profile.

These are the before and after values of those numbers.


Before

Area Moment of Inertia: (mm4): (X) 1.61 x 104 (Y) 6.10 x 104
Ultimate Tensile Strength: 38 ksi
Modulus of Elasticity: 69 GPa

After

Area Moment of Inertia: (mm4): (X) 1.58 x 104 (Y) 6.07 x 104
Ultimate Tensile Strength: 30 ksi
Modulus of Elasticity: 70 GPa

It will also give a little more room for wiring.

new_profile.jpg

Re: Minor Profile change

PostPosted: Fri May 04, 2012 12:52 am
by mxk
Bart,
Do you know if these changes will occur before or after the Inventables first-run?

Re: Minor Profile change

PostPosted: Fri May 04, 2012 1:09 am
by bdring
A few hundred piece are left over from the current profile. The current batch being extruded will be of the new format. Inventables will ship both.

The current material is fine. This was done to address future degradation of the tool.