That's pretty uhh... You should make that your avatar... Good job on the sliders!! Looks sweet.

 

Thank you. Unfortunately the blister is all scabbed up today. I think I'll keep my trademark Unabomber avatar though. Feel free to use it as yours, however

 

What did you end up using bolts for again?

 

Because the bottom face of the bracket was not flush with the frame. We had some assebmly difficulties so everything was not perfectly lined up. I put spacers in there and put a bolt through it to hold it all together. Ideally, and hopefully, I will sometime get over-sized spacers and have them welded in there. But for now, the 1/2" stainless bolts will suffice

 

Won't those bolts get pretty worked over by rocks? I like the slider design and am thinking of something similar. I'll be welding mine one and am actually debating the whole scab plate thing. I just got back from our SoCal BBear trip and witnessed Marlin himself using his sliders throughout the John Bull Trail. How were they welded?.............with no scab plates directly to the frame. He had two gussets on the top face of the roundbar for support. I rode with Mikey (wifesaysi'madumbass) and his are also welded directly to the frame. After some of the hits his sliders took I have no questions about the strength of this welding method.

Andy

 

I don't have the time to show you the real world math...but using scab plates as opposed to just gussets...you get way more contact surface area on the frame to diffuse the loading. Gussets do little but make the point loading worse IMO.

Assuming the same load for each instance, a single leg of a slider that is welded onto a scab plate welded to the frame compared to only a gussetted single leg of a slider that are both welded directly to the frame, the scab plate leg of the slider at the frame surface contact area sees a pressure 16 times less.

Or for arguments sake and using arbitrary numbers...the gussetted slider leg would see 1600 lbs per square inch at the frame while a scab plate slider leg would see 100 lbs per square inch at the frame. Seems pretty clear cut to me which method is best and stronger.

To me it is not that one is right and the others are wrong, it is a matter of some that are good and one that is best.

 

Thanks for the input and if you wouldn't mind sending me a pm with the math calcs, I'd like to learn a little something.

 

What I explained above was just a simple baseline calculation relative to force applied per square inch of contact area or pressure. It didn't take into account metal fatigue, shear loading, frame material thickness, weld material and integrity, blah blah blah...but when it all boils down to it...welded on w/ scab plates is the best option on paper and in practice IMO.

There are many factors to consider that make the scab plates the best option IMO, but they all relate to spreading the loading out on the frame rather than concentrating it in one spot. A gusset does nothing to spread this load out across the fame but concentrates it in one small spot horizontally on the frame, if the gusset goes vertically.

I get paid to sit around and do this kind of stuff all day long 60+hrs/week on pressure vessels, structural steel, heat exchangers, pressure piping, etc...so I do know a little bit about welded connections.

Maybe one day I'll sit down and write it all down and draw some sketches...but not this week.