Need Welding Advice - Concerned About Quality

NatersXJ6

Explorer
I see a few issues here.

1) don’t assume that someone is a good designer just because you think they are smart and they get paid. Some of the worst products in the world were still designed by paid engineers. In order for the welder to produce something good, he must have good skills and a good design.

2) you stated that you don’t know the alloy. In aluminum product design, that is an unforgivable sin. If you don’t know it, assume he doesn’t know it, and it might not have the same material properties as those assumed by your designer. Spec what you need, buy what you spec... again, a good designer will know the right combination of material, strength, and workability to get the best overall product cost.

3) I think you are probably getting what you pay for. $8k seems really low to me for materials AND labor on a large aluminum project done as a one-off and properly welded. Just getting the individual frames square should require building some jigs and support structures and fully welding those frames before proceeding.

4) getting this right isn’t cheap... I think you are learning firsthand why manufactured trailers and campers have high costs (note I still build my own most of the time, despite the cost)

Good luck, but I would suggest that entire thing go to the recycling yard and you start over.
 

john61ct

Adventurer
don’t assume that someone is a good designer just because you think they are smart and they get paid.
I am looking for recommendations for a good designer, willing to turn my SketchUp ideas into spec'd drawings.

Want to avoid over-building, robust but focus on light weight, just strong enough for safe longevity.

Happy to work with someone outside the US, but material specs must use what is cost-effectively available here.

In addition to referrals to specific individuals, suggestions as to online platforms for putting such work out to bid would be welcome.
 

DaveInDenver

Middle Income Semi-Redneck
I see a few issues here.

1) don’t assume that someone is a good designer just because you think they are smart and they get paid. Some of the worst products in the world were still designed by paid engineers. In order for the welder to produce something good, he must have good skills and a good design.

2) you stated that you don’t know the alloy. In aluminum product design, that is an unforgivable sin. If you don’t know it, assume he doesn’t know it, and it might not have the same material properties as those assumed by your designer. Spec what you need, buy what you spec... again, a good designer will know the right combination of material, strength, and workability to get the best overall product cost.
As both a licensed Professional Engineer and a certified welder I can attest that both engineers and welders think the other is a abject moron and must have their hand held at every step. They're both wrong and right.

It's same for every industry. I'm actually an EE by training and experience, went through NASA soldering training very early in my career and realized at that moment that I thought I was competent but wasn't. The techs were really good and I should be asking them specifics about board layouts to make their job easier.
 
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NatersXJ6

Explorer
As an engineering manager, I often tell my project engineers that we aren’t playing individual sports, engineering and design is a team sport, the product is better when everyone is involved from concept to execution.
 

The Artisan

Adventurer
Looking over the project. You said you had it spec'd and had a cut sheet. How did he come up short on materials. That would be my first red flag, imo. His solutions and backyard fixes are totally unacceptable 3/8" gaps and butt welds on a structural section. Also who orders the wrong materials and thinks it is ok to proceed without consulting you first.
Kevin
 
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bapple

Member
I see a few issues here.

1) don’t assume that someone is a good designer just because you think they are smart and they get paid. Some of the worst products in the world were still designed by paid engineers. In order for the welder to produce something good, he must have good skills and a good design.

2) you stated that you don’t know the alloy. In aluminum product design, that is an unforgivable sin. If you don’t know it, assume he doesn’t know it, and it might not have the same material properties as those assumed by your designer. Spec what you need, buy what you spec... again, a good designer will know the right combination of material, strength, and workability to get the best overall product cost.

3) I think you are probably getting what you pay for. $8k seems really low to me for materials AND labor on a large aluminum project done as a one-off and properly welded. Just getting the individual frames square should require building some jigs and support structures and fully welding those frames before proceeding.

4) getting this right isn’t cheap... I think you are learning firsthand why manufactured trailers and campers have high costs (note I still build my own most of the time, despite the cost)

Good luck, but I would suggest that entire thing go to the recycling yard and you start over.

NatersXJ6 - all good points. I'm pretty confident in the design engineer's work. This is an area I'm more familiar with and I was able to follow his finite element analysis and structural recommendations. His day job involves designing part for others to weld so he has some appreciate for the "real" work.

Good data point on the $8K cost. He was not the lowest bid and came with good referrals. Lesson learned.
 

bapple

Member
I am looking for recommendations for a good designer, willing to turn my SketchUp ideas into spec'd drawings.

Want to avoid over-building, robust but focus on light weight, just strong enough for safe longevity.

Happy to work with someone outside the US, but material specs must use what is cost-effectively available here.

In addition to referrals to specific individuals, suggestions as to online platforms for putting such work out to bid would be welcome.

I have used Upwork on several occasions for structural analysis. It's hit-or-miss but very convenient and easy to sort through the guys trolling for overpaid jobs with little accountability. Unfortunately the two guys I would recommend have retired from crowd-sourced work.

Depending on the format that you need, there are a few handy (and free) file converters that can import SketchUp files and export as other types of cad files. Or sign up for a 30-day free SketchUp Pro account to get a little more functionality.
 

DaveInDenver

Middle Income Semi-Redneck
He was not the lowest bid and came with good referrals. Lesson learned.
It's possible he can weld steel fine. Although deviating from the cut sheet and the fit up aren't indicators of good work and I wouldn't personally trust or recommend him.
 

Alloy

Well-known member
As both a licensed Professional Engineer and a certified welder I can attest that both engineers and welders think the other is a abject moron and must have their hand held at every step. They're both wrong and right.

Sadly the morons are increasing. Welding curriculum are being reduced and engineering degrees are obtained by transferring course credits from the Arts.
 

bapple

Member
maybe if the initial approach was email, no middleman platform involved?
Even if one was willing to disregard rules of the crowdsourcing platform, i'd be careful working directly with a freelancer if they are not somewhat local. most crowdsourcing platforms enforce mechanisms to protect both the customer and service provider. it's typically not worth the risk for successful freelancers - they will be kicked out for skirting the rules.
 

NatersXJ6

Explorer
It is likely that your designer is more than competent to run FEA and calculate bending forces, etc...

However, it is tough to tell from the pictures, is most of the structure made from angle versus tube?

I would ask lots of questions, such as:

Did the FEA assume that all the members join at a common point, or did it show the angle coming in next to the vertical member as seen in your photo? Did it show the stacked 1x1? I would assume not. BTW, replacing 1x2 with 2x 1x1 is not kosher in over 99% of applications, and the failure modes introduced will be a problem. Welding that in a way that safely mimics 1x2 without heat damage and warping is difficult at best.

Overall, you identified that the whole animal looks sketchy. Go with your instincts there. It wasn’t right.
 

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