Bobcat 250 EFI + 12VS Extreme Flux Core to Bottle

[Bob Miller]

Jet

Here is what we are currently building at our shop. We have complete 1 & it is being used currently, and are just finishing up 2 more. We will most likely be building 10 more. The customer wanted a hitch that was bulkier & stronger than a locally sourced cheap alternative. He uses them on compact CAT 1 tractors that pull fruit bin trailers for cherry harvest.

An operator can more easily load/unload/hook up to trailers running the hitch off 3 point. Also, this places the pivot point of the trailer "further back" from the tractor, allowing for tighter turns without binding & tire rub.

The builder is grinding welded surfaces to a "v" prior to welding. He is making 2 passes with 1/8" 6013 on our bobcat 250.

Nat,

Try 7018 jet on those welds, it will smooth them up real nice.
6013 will run smooth with a little more heat.
Your welds look cold around the toes.
Good Luck,
Bob

[farmer welder]

Hi, I"m probably off topic a little bit. But I was wondering how you did such a neat an tidy job cutting the plate for the three point hitch frames?
Is that done with a plasma cutter? Thanks Joe.

[Tryagn5]

Is the undercut a good thing? No. Will it fail because of it? Not likely. It has a lot of other weld holding it plus it goes through the rear plate completely & is tied into the second tube.

I would be more concerned of the design. The side plates should go forward more by the rear spring hangers. Look at any pickup truck hitch & they go forward more to spread the load. The hitch you show is very beefy for what is there but it is mounted to the rear (12"?) of the frame.

Is it going to tear off? Not likely.

The 1/2" side plates are overkill. Most store bought hitches are 1/4" & the class V maybe 3/8" thick side plates.

His design is not bad, probelm he has is there is no way to affix the hitch farther on frame rails, the f350-f550 chassis have a rearmount fuel tank which makes hitch placement difficult, thus why i prefer to make a hitch plate like what is seen on dump trucks or larger 6 wheelers. Also prefer to weld to the frame, although in this case the service body probably makes his style of hitch the only way to fit.
Kevin

[MMW]

Is the undercut a good thing? No. Will it fail because of it? Not likely. It has a lot of other weld holding it plus it goes through the rear plate completely & is tied into the second tube.

I would be more concerned of the design. The side plates should go forward more by the rear spring hangers. Look at any pickup truck hitch & they go forward more to spread the load. The hitch you show is very beefy for what is there but it is mounted to the rear (12"?) of the frame.

Is it going to tear off? Not likely.

The 1/2" side plates are overkill. Most store bought hitches are 1/4" & the class V maybe 3/8" thick side plates.

[mbramble]

He's maybe thinking the undercut is the sign of a good weld because he is obviously penetrating into the base metal. However, if he doesn't fill that back in with weld metal then it leaves a defect that puts stress onto the weld.

[kize]

Thanks for the good suggestion. He's our main mechanic...very gifted person...he was born deaf, but excels at mechanical skills. We needed a full-time mechanic, and he came highly recommended from a mutual friend. He has since taught me to sign American Sign Language & we get along real well...loyal fella. He and I could take a course at the local junior college together & learn much.

That sounds like a fantastic plan. You both would gain knowledge and skill. I commend you.

[RedBarnNate]

Undercut is most definitely not a sign of a properly burned in weld. It is unacceptable past certain thresholds, which it appears these are far past that point. Also, his welds in one of the pics is very very porous. He had some sort of contamination in the weld, that when burned off, leaves pin holes in the weld. This all leads me to think he has no qualification to be doing any sort of welding work where if his work fails somebody could be hurt. It looks like his fab skills are decent, just doesn't appear to have the necessary training to be considered any sort of a welder. The fact he is trying to justify the quality of his work is a sign he really is ignorant in the welding field. Maybe an evening course at a local tech school so he can take what he knows now and run with it.

Thanks for the good suggestion. He's our main mechanic...very gifted person...he was born deaf, but excels at mechanical skills. We needed a full-time mechanic, and he came highly recommended from a mutual friend. He has since taught me to sign American Sign Language & we get along real well...loyal fella. He and I could take a course at the local junior college together & learn much.

[Cgotto6]

Undercut is most definitely not a sign of a properly burned in weld. It is unacceptable past certain thresholds, which it appears these are far past that point. Also, his welds in one of the pics is very very porous. He had some sort of contamination in the weld, that when burned off, leaves pin holes in the weld. This all leads me to think he has no qualification to be doing any sort of welding work where if his work fails somebody could be hurt. It looks like his fab skills are decent, just doesn't appear to have the necessary training to be considered any sort of a welder. The fact he is trying to justify the quality of his work is a sign he really is ignorant in the welding field. Maybe an evening course at a local tech school so he can take what he knows now and run with it.

[RedBarnNate]

I am on my phone so it is hard to see some of the pictures. But the last one... holy undercut! That is one giant stress riser right where the tongue weight sits on an unknown weight trailer being pulled by a 1-ton truck?

I'm glad you are posting pictures and learning, but you should learn from someone else. Those welds are not okay.

Go spend some time on weldingtipsandtricks.com and see what jodi has to show you. That should give some perspective.

Ok, so undercut isn't a sign of strength. Glad I'm learning what to look for. As far as convincing this person that his welds are no good & that I know better from reading on a forum, that might be the difficult part of the situation.

Thanks for the link. Little bit of a wind taken out of the sails feeling now, but that's ok, just another problem to solve here at the family business.

It is hard to see but if he just used the 1/4 angle for the mounting flange that will not be enough strength. The hitch should not be just bolted to the bottom flange of the truck frame, instead it should be bolted to the wide vertical part of the truck frame.
Kevin

The mounting flange is built from 1/2", and yes it is bolted to the frame of the truck. It also has brackets that bolt to the underside of the bumper to support the rear bumper.

Lots of undercutting on the welds, looks like there is to much heat, also welder has not mastered his weave techique. I bet he cranked the welder and tried to burn it in. Worse hitch i have seen no, professional hitch not close, i suggest you go look at the welds on thr tractors , they all should look that way, keep in mind hes welding everything in postion. Should be an easy weld.
Kevin

He seems to think that undercutting means a strong weld. Thanks for the feedback. We are a small business, and occasionally have welding/fabrication jobs. We can't afford to hire a separate employee for inconsistent jobs.

[Meltedmetal]

I am going to swim against the current a little here. I don't know what will be pulled or how it will be treated but I don't see anything there that will fall off. Is it how I would weld it? No, absolutely not. I would expect cracks to develop over time as it is done so check it regularly as you should with any hitch. I have a personal dislike of 6013 and for that matter 7014 and would only use them to weld lunch boxes unless I was really stuck with nothing else, but that's just my opinion and my opinion isn't worth much. It's not a poster hitch but I've seen much worse on the road. I gave up building hitches a long time ago because here the DOT likes to see the approvals punched in the steel work and frankly for the liability involved commercially built hitches are cheap. As for bolting to the frame web instead of/as well as the flange look at what the commercial guys are doing: http://www.thehitchstore.com/hitches...s-c-20_22.html
Again , just me, but I wouldn't mig weld a hitch. I'd use 7018 but I'll admit I haven't used mig enough to trust it. Seems to me that mig can make some really pretty welds and fast but without an engineer specifying procedure and good weld prep, it seems easy to end up with a nice looking, fast, poor weld. Chalk it up to lack of mig experience I guess.---Meltedmetal

[Tryagn5]

mounting of hitch

It is hard to see but if he just used the 1/4 angle for the mounting flange that will not be enough strength. The hitch should not be just bolted to the bottom flange of the truck frame, instead it should be bolted to the wide vertical part of the truck frame.
Kevin

[Tryagn5]

I appreciate the feedback. Can you guys look at a hitch we built for our F350 service truck? This is the same mechanic, but using a Millermatic MIG setup. Does this look like a better finish job to you? Thanks

Lots of undercutting on the welds, looks like there is to much heat, also welder has not mastered his weave techique. I bet he cranked the welder and tried to burn it in. Worse hitch i have seen no, professional hitch not close, i suggest you go look at the welds on thr tractors , they all should look that way, keep in mind hes welding everything in postion. Should be an easy weld.
Kevin

[elvis]

I am on my phone so it is hard to see some of the pictures. But the last one... holy undercut! That is one giant stress riser right where the tongue weight sits on an unknown weight trailer being pulled by a 1-ton truck?

I'm glad you are posting pictures and learning, but you should learn from someone else. Those welds are not okay.

Go spend some time on weldingtipsandtricks.com and see what jodi has to show you. That should give some perspective.

[Cgotto6]

Oh my god. That last picture...And that thing is Rollin on down the road!

[vin-man welding]

well, I don't want to start a fight ether but if that was a welder working for me, it would be the first and last day.
I run Lincoln 233 1/16 in my suitcase, love it. way better then 21b
with gas the tri 7 is good. hard wire is hard wire.
the only rod to be burning it 7018 unless it needs to be 11018.