Oops - Log splitter fail.

[Paul99]

Having finally had enough dry weather to allow us to get the digger and dumper into a very boggy field without making too much mess we've been catching up splitting a load of ash, elm that was dropped back Christmas time and some well seasoned and seriously hard evergreen oak for a customer we do a lot of building work for. All was going well until the splitter decided to commit suicide when I was trying to force it through a few knotty pieces:

This is not the splitter I built myself but one a fabricator friend had promised us for a very long time - after 6 months of waiting I built my own only for this one to finally turn up.
By pure coincidence they are similar in the design only I built mine much more heavily - way OTT according to those who have seen them side by side. Well I've had the last laugh... as pictures show heavy channel (6mm thick top) with a few webs added just isn't heavy enough . To be fair to it though being lighter to move when off the digger it's easier to move about the workshop and as a result it's been used in preference to mine all along and in 12 months or so it's split a fair amount of wood (getting on for 100 tonnes some of it with more knots than wood ). The base has been slowly but surely creeping away from square for a while and with me pushing it too hard with some tough stuff I finally finished it off. Luckily it happened at 4.30pm so only half an hour lost before turning up with my OTT splitter the following morning to finish off the job without any problems at all

It's now on the ever growing list of things to get fixed. When I get around to it it'll be treated to a nice 12mm plate base with extra supports underneath like I put on mine

 

[brokenbiker]

i dunno if its just me but the weld on the bottom pic doesn't look like is fused at the bottom where the split is. But atleast it was the metal that went rather than the weld, sort of a good sign i suppose although i agree a heavier base with a bit more weld on it would have been better but it has lasted quite well considering how much you have used it

 

[piman]

Hello Paul,

if the I beam was rotated 90 degrees and the base made of a section equal in size to the I beam it would be much stronger without having to go up in thickness. I.e, the strain is then put onto the vertical sides of the box rather than across the relatively weak face.

Alec

 

[norlander]

I reckon you are right about using the 12mm plate for the repair.
From memory from my fabrication days, we would not have welded an RSJ direct to a channel, a plate would have been welded to the end of the RSJ and the RSJ, bolted up or welded to the channel-usually bolted from memory-probably for ease of assembly, but also strip down if needed, plus shimming if necessary to get the job square.

 

[clift_d]

Alternatively a section of the same IC used as an upright would have been better. The problem with attaching to the web of a PFC/IC/IB, as done here, is that the steel of the web is only about 2/3 of the thickness of the flanges.

 

[Paul99]

Well I spent an hour or so earlier cutting away the bust up base ready to add something better. A few things surprised me having looked at it a lot more closely... There was very little penetration in the welds and as Brokenbiker noticed there appeared to be a lack of fusion on the one weld at the front in particular - looks like the guy was weaving and coupled with the lack of penetration the weld toes had peeled away under the huge strain:

Saying that mind it has lasted well and it's clear that the metal itself failed, it's quite impressive how much those welds actually managed to hold:

I've started mocking up a new base and using what I have to hand I think it's going to end up something like this:

Obviously the 12mm base will be closed in on all sides with 12mm plate and several webs added underneath and a few gussets on top too to stop any flex. Ideally I'd have liked to have welded two plates across the RSJ flanges and sit the 12mm plate on top of that but I'm limited by the length of the RSJ and the travel of the ram so something like the above will have to do - if that old channel lasted until now this new base should be fine I think. I'll probably make a few passes to build up a bigger fillet too just to be sure. I haven't yet made up my mind whether to mig it or play it safe and use the arc which I have lot more experience with. Will have to see what mood I'm in on the weekend.

 

[lshigham]

That flat looks familiar - nice to see it being put to use!

If you want to play it safe definitely arc it, particularly if you are going to have to do a multipass weld with the mig

 

[norlander]

+1 for arc. Think your plan for repair is sound with the webs ands gussets.

 

[Paul99]

That flat looks familiar - nice to see it being put to use!

If you want to play it safe definitely arc it, particularly if you are going to have to do a multipass weld with the mig

Yep - that's a couple of the short lengths of plate I had from you - too good to use on a job like this really but as it's already to hand I'm going to use it.

 

[Paul99]

A little more progress:

I opted for 10mm plate to box the base in - going by looks it's OTT so should be plenty. Can't make my mind whether to have two shorter webs underneath running perpendicular to the splitting wedge or one longer one down the middle running parallel to it - I don't think it'll make a lot of difference as I'm not sure their needed at all. With a 3mm or so gap in the joints I'm getting just short of 100% penetration with the bead sitting nice and flat with the mig running near flat out (255amp) so the rest of the base will be migged especially as I will weld from both sides but I'll still likely use the arc to join the RSJ to the base + fix the gussets.

 

[Welderpaul]

The fit-up looks good there.

If it was me, i would set the flats 12-15mm in from the edge of the top plate so you can get a nice big fillet both sides of the plate - just makes it that bit stronger.

 

[Paul99]

The fit-up looks good there.

If it was me, i would set the flats 12-15mm in from the edge of the top plate so you can get a nice big fillet both sides of the plate - just makes it that bit stronger.

Doh - didn't even think of that but makes perfect sense. Thank you for the pointer.

 

[clift_d]

Can't make my mind whether to have two shorter webs underneath running perpendicular to the splitting wedge or one longer one down the middle running parallel to it - I don't think it'll make a lot of difference as I'm not sure their needed at all.

Probably not needed but my gut instinct would say for belt & braces overkill a gusset underneath in line with the I-beam web and splitting head, and then two infill gussets either side of this & perpendicular to it, running to the sides of your base box, and in line with the flange of the I-beam that your splitting head runs down

 

[Paul99]

Finally had a few hours spare to finish this repair off. I decided having got it all tacked up real well to carry on welding it up as it was rather than follow Welderpaul's suggestion above - it's definitely more than strong enough this time around but will keep the idea in mind next time.

And the underneath:

The square spigot is simply to slide a simple length of box section on to as a leg to hold it at the required at a comfortable height and blocks are small enough to lift up onto it.

The base itself was all mig welded - well I did start out with the arc but was slow going and TBH I was getting as much if not more penetration with the mig flat out at 255amp as I was with 4mm 6013 rods running at 180amps. By the end of it I was getting the hang of the mig on this kind of thickness though there's still plenty of room for improvement:

I did actually chicken out and arc weld the base to the RSJ as I was just more comfortable with the arc for these more critical welds. Having hardly used the arc welder since getting the mig I was definitely rusty straight runs were easy but had one or two slag inclusions on internal corners that needed sorting out no matter - it's still more than good enough.

It'll get a good test over the weekend on 3 big trailer loads of large rings I collected this afternoon - there's something like 5 tonnes of softwood (larch mainly) and 1 tonne of oak - if it lasts all that I'll deem it finished and will give it a coat of paint.

 

[Justme]

Nice job.

Put some texture on that base plate to help stop odd shaped logs from moving.