Zor

Hi All,

I do not understand why the gluing ( cementing ) of this item was chosen while areas needing much stronger joints are required.

I think that most regular wood glues and epoxies are much harder then the materials they bind.

The binding strength to hold under stress ( impact peak forces ) seems to me to be the purpose of selecting a binding agent. The ability of the binding agent to hold depends on the penetration to some extend and the material being cemented may give ( break ) just beyond the penetration.

Many bondings have little or no penetration such as gluing to glass or metal surfaces.
The binding in such cases is more molecular than porous penetration. In such cases the area of binding is more important. This also apply of course to penetrated bindings.

I have developped the habit of filleting all gluing to increase the binding areas.
I have been rewarded with much less damages in the multitude of crashes over the years.

There are also methods of helping the bound structure to resist the breakage of the glued joint. Glued joints rarely break under compression. They break under tension, shearing, twisting or tangential forces.

Zor

olnico

Shear test of the USB with E-20NS.
That was a big surprise. I was expecting the glue joint to be slightly weaker than with E-20HP. In fact this was not the case at all.
The bracket did hold till 62.5 kgs of load!
That is a mighty 125 kgs for a pair of brackets and 170 PSI shear strength.

Here is a picture of the test at 62.5 kgs, just before it broke.

dbsonic

My Feedback: (3)

Very interesting. Compared to epoxy, the Hysols are far superior. Looking fwd to your next test.

olnico

Gemtlemen, here is the winner, so far. Hysol 9462!

Test at 50 kgs/ 110 lbs:



60 kgs/ 132 lbs:



65 kgs/ 143 lbs:



The glue joint sheared after a few seconds at this weight in an impressive explosion.

The shear strength of the glue joint in these conditions is 65kgs for 5.165 cm2 or 12.58 kgs/ cm2 or 179 PSI.

Here is the picture of the bracket after failure:



This is interesting because part of the glue joint failed on the wood interface and part of the bracket failed on the PYCABS interface. This is a good validation of the shear strength of the material in real conditions.

BTW this also validates the resistance of the Ultimate Servo Brackets at a mighty 130 kgs/ 286 lbs per servo. This bracket will hold 1700 oz.in of torque without failing!

marc s

Oli are you able to test 9464, from what I understand it very similar to 9462, comparatively less money than 9462 and is a grey colour and thixo too, I've used it and find it god but would like to see how it stands up if you have time/options to test it.

Being grey it blends nicely with any carbon faced formers/plates etc too and your PYCABS black products...

marcs

olnico

Hi Marc,.
I just checked with Loctite USA. They do not have 9464 on the dealer's catalogue.

marc s

How strange - CAT No 36692

marcs

olnico

That's a Euro only reference. I will check if I can get a sample from Loctite USA.