i know there are a few pro welders on here so my question is if someone said i want a 10mm throat butt weld on a lump added onto a 32mm bar, would you
laugh at them, or would you just get on with it?
detail behind the question's in the next post
cheers
tom
a part of my final year project, i've been working on the design of a drop weight impact rig for the testing of composite materials.
dissertation's due in next monday but i'm just working through my final designs of the bits that aren't to be machined yet. i've
been doing a weld stress calc on the safety stop which is a 32mm dia en8 bar with a 27mm wide lump of en3a welded onto it.
when the sled falls from 2.5m, max drop height, assuming the 29kg sled's brought to rest in 6milliseconds on a pair of bullet shaped bump stops,
the calc suggests i need a 10mm throat butt weld all round.
is that....possible? i imagine it needs more than one pass but we have 250amp mig and a monster stick kit in uni. i don't have to actually weld
it but it'd be nice to come up with a design that's actually feasible.
it will leave an unwelded section on the back face but it's not going to be subjected to any real cyclic load. it will possibly be impacted once
in a blue moon when my control system fecks up.
tom
I don't understand the question I think a drawing would probably make it a bit clearer.
Regards
Davie
quote:think its a 10mm fillet weld your after
Originally posted by indykid
i know there are a few pro welders on here so my question is if someone said i want a 10mm throat butt weld on a lump added onto a 32mm bar, would you laugh at them, or would you just get on with it?
detail behind the question's in the next post
cheers
tom
this is what i mean.
the top of the square face would be impacted if the sled ever hit it.
i could increase the length of the bar to give a fillet weld top and bottom but there's no room for it on the sides
thiking about it, i'll probably spec it as that just to save messing with trying to bevel the round face.
any other thoughts though, keep them coming.
cheers
tom
from what I can see on your drawings if it was prepared and welded properly the 2 pieces would never come apart.....ever. .m.
looks plenty strong to me.
if this was for a one off thing, but high use, then the cost of getting something cast in one solid piece could probably be justified?
quote:
Originally posted by blakep82
looks plenty strong to me.
if this was for a one off thing, but high use, then the cost of getting something cast in one solid piece could probably be justified?
cast and impact sounds bad to me.
bringing a 29kg plate travelling at 7m/s to rest in 6 milliseconds requires an average force of 40600N......4.1 tonnes in static terms
i think it looks strong enough too. the maths agrees but it's the technicalities of producing the weld i need to know about.
it's a 2 off btw so casting/forging are not an option
ta
tom
Yep looks good to me thats how i would do it
Jacko
quote:
Originally posted by jacko
Yep looks good to me thats how i would do it
Jacko
ah yeah, not casting then, but who about machining on a CNC mill or something?
quote:
Originally posted by blakep82
ah yeah, not casting then, but who about machining on a CNC mill or something?
Just weld with low hydrogen rods, the weld will be stronger than the parent material. E6011's from memory, but make sure they are ultra dry when you use them (use a heated quiver)
Whatabout a thick dowel through the pair of parts?
quote:
Originally posted by Mark Allanson
Just weld with low hydrogen rods, the weld will be stronger than the parent material. E6011's from memory, but make sure they are ultra dry when you use them (use a heated quiver)
quote:
Originally posted by blakep82
ah yeah, not casting then, but who about machining on a CNC mill or something?