>>>>> Well I am still a wee bit uncomfortable with NO reinforcement.
>>>>> How about just a couple of .065" thick 4130 straps 1/4 inch
>>>>> wide laid flat? Skip welded every one inch with a 1/4 inch
>>>>> long weld.
>>>>>
>>>>>
>>>>> Paul Lamar
>>>>>
>>>> You are the engineer.   I felt it passed the load test o.k. without
>>>> reinforcement. But welding a little strip on each side is not a
>>>> problem if it will really strengthen the beam so let's do it.  There
>>>> may be a problem finding such a strip.  I would not be surprised if
>>>> it comes off the shear looking like spaghetti. Not available in the
>>>> ACS catalogue.  Cold Roll might be available in that size.   Would
>>>> that be acceptable?   Jerry
>>>> I think shearing it will be OK Jerry. It is thin enough to twist
>>>> back into shape. You can also clamp it down to the beam.
>>>> Mild steel might be OK because I am mainly worried about
>>>> local buckling or local crippling to use a high tech term.
>>>> Paul Lamar
>>>>
>>>
>>>
>>> What about a piece of 3/16" rod ?
>>>
>>> John
>>>
>>> Good idea make it 1/4 inch and I would feel pretty good.
>>>
>>> Paul Lamar
>>
>> Are  you saying that .250 dia.  mild steel rod will be
>> acceptable?  .   What length?    Jerry
>>>
>>
>> About an inch longer on each end than the slot.
>>
>> Paul Lamar
>
>
>
> Hi Paul and Jerry,
> If this part of the beam is in compression, and has not failed, what do
> you hope to achieve by adding more metal?
> Following with interest, Dave McC
>
> I just feel more comfortable with a bit more safety margin as it
> would add very little weight. I think Bill Dube's FEA of the beam will

show

> this area to have the highest stress. There is always a compromise
> when designing anything between cost and weight. If this were a space
> craft or helicopter part the beam would be highly complex as in this
> photo of Richard Martin's cost no object helicopter Schertz beam. We
> chose to keep it  simple and cheap and bend it up out of rectangular
> sheet therefor the stress distribution is way less than the ideal

constant.

>
> Paul Lamar
>

Paul

I personally am very attracted to that type of mount structure shown on

the

helicopter mount.  Should be easy to weld up in thin  1.5mm stainless

plate.

Say isn't Richard in the Seattle area?  I would like to stop in and see

him

also, if you have his contact info.

Doug in Japan

Doug,
Is stainless strong enough. I tend to think of stainless being prone to
cracking through flexing - then again if it's stiff enough?
Personally I thought chrome molly ( 4130) might be a safer option.
I agree with you it is an excellent looking mount and could be easily laser
cut and welded with a strip - strong as hell.
George ( down under)