Handling conception independantly from material dimensions

[AlexLachance]

I'd like to know, how do you guys handle conception independantly from material dimension?

One of the issue we face a lot as of late, is that we have to recreate new drawings in concordance to the materials that we currently have in-hand. In general, our standard materials are, most of the time, always in-hand and we face no issues.

But, there are external factors for both us and our suppliers that complicate things. Because of that, we often find ourselves having to find material that is not within the standard dimensions that we buy, so that our production can continue without coming to a stop.

Because of that, we often have to recreate drawings accordingly to whatever material that is ordered to replace our missing standard plates.

We even have to recreate drawings sometimes, because our supplier said that the material would have a certain dimension, and that these dimensions tend to vary ±1/2" on both dimensions.

I was wondering, how do you guys handle conception so that if the material dimensions change, you do not have to change/adjust design.


We aim to be as light as possible, so weight is a factor.
We also aim to have the least "operations" made to create a part(in terms of production), so if we're able to use a plate straight from the supplier, that works even better for us.
We are asked to keep the welding to a minimum,when possible.

[Glenn Schroeder]

Howdy Alex,

I don't know if this helps or not, but when the preliminary design calls for material that I'm not confident is readily available I try to check with our supplier as early in the process as possible. If I'm told that "No, we can't get that," or "Yes, but it's 6 months out," or "Yes, we can get it, but there's a minimum order of XX tons" (when we need a few hundred pounds), I go to the engineer in charge of the process, let him or her know that, and suggest alternatives.

The earlier I find out about problems the easier they are to fix.

[DanPihlaja]

I'd like to know, how do you guys handle conception independantly from material dimension?

One of the issue we face a lot as of late, is that we have to recreate new drawings in concordance to the materials that we currently have in-hand. In general, our standard materials are, most of the time, always in-hand and we face no issues.

But, there are external factors for both us and our suppliers that complicate things. Because of that, we often find ourselves having to find material that is not within the standard dimensions that we buy, so that our production can continue without coming to a stop.

Because of that, we often have to recreate drawings accordingly to whatever material that is ordered to replace our missing standard plates.

We even have to recreate drawings sometimes, because our supplier said that the material would have a certain dimension, and that these dimensions tend to vary ±1/2" on both dimensions.

I was wondering, how do you guys handle conception so that if the material dimensions change, you do not have to change/adjust design.


We aim to be as light as possible, so weight is a factor.
We also aim to have the least "operations" made to create a part(in terms of production), so if we're able to use a plate straight from the supplier, that works even better for us.

What is the manufacturing process that you are talking about?

Stamping/machining/sheet metal/etc...

If machining, then I wouldn't worry about it at all except to list the new material as an additional option.

If something else, then start making your drawings to suit both (or all) types of material that are acceptable. List all the materials that are allowable.

OR if that list varies too often or grows too large, then I have seen drawings reference a separate specification that lists all the conditions that allow for different materials and sizes. So you could create this specification, then reference it on the material section of the drawing. Then make sure that your suppliers all have a copy of the updated version of this spec.

[AlexLachance]

Howdy Alex,

I don't know if this helps or not, but when the preliminary design calls for material that I'm not confident is readily available I try to check with our supplier as early in the process as possible. If I'm told that "No, we can't get that," or "Yes, but it's 6 months out," or "Yes, we can get it, but there's a minimum order of XX tons" (when we need a few hundred pounds), I go to the engineer in charge of the process, let him or her know that, and suggest alternatives.

The earlier I find out about problems the easier they are to fix.

That's one of the issue. We check these things 6 months ahead and 6 months later the answer we received does not match the situation. In other words, we were told we'd have material at this date, and the material is either late or does not have the dimensions it was supposed to have. Positionning of certain components can also be dependant of these dimensions at times.

[AlexLachance]

What is the manufacturing process that you are talking about?

Stamping/machining/sheet metal/etc...

If machining, then I wouldn't worry about it at all except to list the new material as an additional option.

If something else, then start making your drawings to suit both (or all) types of material that are acceptable. List all the materials that are allowable.

OR if that list varies too often or grows too large, then I have seen drawings reference a separate specification that lists all the conditions that allow for different materials and sizes. So you could create this specification, then reference it on the material section of the drawing. Then make sure that your suppliers all have a copy of the updated version of this spec.

Most of the missing "material" is sheet metal, in varying thicknesses, so it's generally plasma cut, sometimes with bends, rarely with machining. For the rest of the post, I'll use 1/8" thickness as the material I'm speaking of.

The varying dimensions can vary from 44" to 98" inches in width and from 101" to 144" in length, which is what makes everything so hard for us to "process".

To be clear, our standard materials are 98" x 101" and 60" x 120". When these are not in stock, it is when we end up having the issue of "varying plates"

[bnemec]

Most of the missing "material" is sheet metal, in varying thicknesses, so it's generally plasma cut, sometimes with bends, rarely with machining. For the rest of the post, I'll use 1/8" thickness as the material I'm speaking of.

The varying dimensions can vary from 44" to 98" inches in width and from 101" to 144" in length, which is what makes everything so hard for us to "process".

To be clear, our standard materials are 98" x 101" and 60" x 120". When these are not in stock, it is when we end up having the issue of "varying plates"

That's one reason why our LASER work centers / team lead does the nesting. We try to keep with the policy that the drawing defines what the part should be when stocked, not how to make it. One example is we have some 5/16 diameter pins that we turn out on lathes. Somewhere along the way MFG phased out an old CNC Lathe and replaced it with better one, but either the collet cannot chuck 5/16 or it was more economical to turn larger stock due to spindle speed needed. Anyway, they don't make the 5/16" pin from 5/16" material, usually it's 3/8 stock even though raw 5/16 would be fine for the pins.

I couldn't care less what size sheets they order in for the lasers, but our orders are scheduled by forecast demand, not per job or order of finished product.

Heck, we have some 1" wide ~1/8" thick parts that they will cut out of 11ga sheet or run off 1" x 1/8" strip stock-based order size for the part and work center scheduled capacity.

[AlexLachance]

That's one reason why our LASER work centers / team lead does the nesting. We try to keep with the policy that the drawing defines what the part should be when stocked, not how to make it. One example is we have some 5/16 diameter pins that we turn out on lathes. Somewhere along the way MFG phased out an old CNC Lathe and replaced it with better one, but either the collet cannot chuck 5/16 or it was more economical to turn larger stock due to spindle speed needed. Anyway, they don't make the 5/16" pin from 5/16" material, usually it's 3/8 stock even though raw 5/16 would be fine for the pins.

I couldn't care less what size sheets they order in for the lasers, but our orders are scheduled by forecast demand, not per job or order of finished product.

Heck, we have some 1" wide ~1/8" thick parts that they will cut out of 11ga sheet or run off 1" x 1/8" strip stock-based order size for the part and work center scheduled capacity.

Yeah, it's a bit more complicated here, since we build trailers, we have regulations to follow, and as I say, we build things and aim for them to be "as light as possible", which means that perhaps switching from 3/16" thickness to 1/8" could perhaps be the difference between no issue, and major issues. There are components that can vary in thickness, but those are a lot less frequent then the other way around.

It's also a lot harder to keep track, when you concider we have to give warranty and that if things vary as such, it is a lot harder to figure out what is the cause of the claim. For instance, Client A has Trailer A, Client B has Trailer B. Trailer A has been built with the standard. Trailer B has been built with varying dimensions(thicknesses, for instance).

Trailer A has no issues
Trailer B has issues.


We'd have to build some sort of "history" of all these changes that would be made by our nesting department, and most of these changes would also require approval.

[Glenn Schroeder]

That's one of the issue. We check these things 6 months ahead and 6 months later the answer we received does not match the situation. In other words, we were told we'd have material at this date, and the material is either late or does not have the dimensions it was supposed to have. Positionning of certain components can also be dependant of these dimensions at times.

I don't know of any way to get away from having to go back and change or adjust the design when that happens.

[AlexLachance]

I don't know of any way to get away from having to go back and change or adjust the design when that happens.

Yeah, neither do I, I'm just hoping that having this discussion on here can either provide me with a solution, or allow us to have some sort of brainstorm that I, and others, could then correlate from.

[zxys001]

I'd like to know, how do you guys handle conception independantly from material dimension?

One of the issue we face a lot as of late, is that we have to recreate new drawings in concordance to the materials that we currently have in-hand. In general, our standard materials are, most of the time, always in-hand and we face no issues.

But, there are external factors for both us and our suppliers that complicate things. Because of that, we often find ourselves having to find material that is not within the standard dimensions that we buy, so that our production can continue without coming to a stop.

Because of that, we often have to recreate drawings accordingly to whatever material that is ordered to replace our missing standard plates.

We even have to recreate drawings sometimes, because our supplier said that the material would have a certain dimension, and that these dimensions tend to vary ±1/2" on both dimensions.

I was wondering, how do you guys handle conception so that if the material dimensions change, you do not have to change/adjust design.


We aim to be as light as possible, so weight is a factor.
We also aim to have the least "operations" made to create a part(in terms of production), so if we're able to use a plate straight from the supplier, that works even better for us.

Can you have two or more design designations per those stock sizes? Designate the PN's as (A) ideal build and (B) alternate, (C) alternate,..?

[AlexLachance]

Can you have two or more design designations per those stock sizes? Designate the PN's as (A) ideal build and (B) alternate, (C) alternate,..?

That is how we are currently "working it out", but it's also what I'd like to avoid, as it forces us to update multiple drawings when changes are made rather then one. It becomes exponential quite fast.

I don't think there are any ideal alternatives, but I'd love for one to exist..

[DanPihlaja]

Can you have two or more design designations per those stock sizes? Designate the PN's as (A) ideal build and (B) alternate, (C) alternate,..?

This is what I meant by adding an internal specification instead of material in the material area.

That way, the specification will call out all the alternatives and their conditions.

Then, on the drawing, you only have to make sure that you are referencing the correct revision of the spec. and make sure all your suppliers have a copy.

[bnemec]

That is how we are currently "working it out", but it's also what I'd like to avoid, as it forces us to update multiple drawings when changes are made rather then one. It becomes exponential quite fast.

I don't think there are any ideal alternatives, but I'd love for one to exist..

Is it possible to divide into a couple of categories? Some changes/alternatives require design validation (FMVSS requirements, fatigue analysis, mating components need to be changed for fitup, etc.) where others may just be a change to alternate material? If the change requires design validation then I feel that the drawings aren't the problem, its that production wants a part change, vs just material change.

I'm guessing you don't know are cannot specify alternate materials ahead of time?

[AlexLachance]

Is it possible to divide into a couple of categories? Some changes/alternatives require design validation (FMVSS requirements, fatigue analysis, mating components need to be changed for fitup, etc.) where others may just be a change to alternate material? If the change requires design validation then I feel that the drawings aren't the problem, its that production wants a part change, vs just material change.

I'm guessing you don't know are cannot specify alternate materials ahead of time?

I guess I might have mispoken when I said changes in materials. What I meant, is that most of our components and designs are built around our standard plate dimensions and that when these are not in stock, we end up having to do changes, and those changes have impacts over the rest of the project.


Here's two concrete example, I can't provide pictures but I'm sure you can imagine what I mean.

The crossmembers of the example trailer are 12" apart from each other. Sometimes they vary by more or less then 2 inches, so that they do not cause conflict with other components. These are not problematic in terms of production.

Our floor is made with a sheet of 288" length x 96" width, which we either buy the correct dimensions or bigger and have the production cut it to the appropriate dimension.

Well, now we sometimes have to buy the plate with shorter dimensions, either width or length. Width isn't much of an issue, but length is. When length varies in shorter dimensions, the impact is far greater as we might have to reposition trailer crossmembers so that the floor ends on top of a crossmember and not in between two of them.

The same thing applies on our walls too. For instance, we have a wall made with plates of 52 inches, each time the plate ends, another plate is crossed over it by 1/2".
Each plate crossover is covered by a wall post for aesthethic reasons. Our Wall posts are 26" C/C from each other.

So what we do is there ares plate that have a different dimension so that we can use 52" as much as possible while also having the most joint hidden possible and what remains is "special" length plates to cover the rest.

When the width varies by less then an inch, we have the crossover vary so that we do not have to redo drawings. When it's higher in variation, we have to rebuild the entire wall pattern, be it plates or post position.

[AlexLachance]

This is what I meant by adding an internal specification instead of material in the material area.

That way, the specification will call out all the alternatives and their conditions.

Then, on the drawing, you only have to make sure that you are referencing the correct revision of the spec. and make sure all your suppliers have a copy.

We have some things that work as such, but these are essentially part of the conception of the "product", so they cannot vary in that manner. It could cause a client to receive a trailer that isn't identical to the same trailer that was built 2 months before, which would be hard for us to "explain" when questionned about it by the client.

The reason I am looking for a solution to a problem that doesn't seem to have one, is that the problem has been on-going ever since COVID started, so the "alternatives" we have which would be sort-of temporary solutions, seem as if they will require us to find a permanent solution.

I'm a bit eluded by this, and I'd love to find a solution that would save all the hassle that we currently have, rather then one that's basically throwing the problem on someone else.

Edit: We're also asked to try to keep the welding to a minimum, which is why we build the floor for instance with a plate of 288" rather then 6 plates of 48".

[bnemec]

I guess I might have mispoken when I said changes in materials. What I meant, is that most of our components and designs are built around our standard plate dimensions and that when these are not in stock, we end up having to do changes, and those changes have impacts over the rest of the project.


Here's two concrete example, I can't provide pictures but I'm sure you can imagine what I mean.

The crossmembers of the example trailer are 12" apart from each other. Sometimes they vary by more or less then 2 inches, so that they do not cause conflict with other components. These are not problematic in terms of production.

Our floor is made with a sheet of 288" length x 96" width, which we either buy the correct dimensions or bigger and have the production cut it to the appropriate dimension.

Well, now we sometimes have to buy the plate with shorter dimensions, either width or length. Width isn't much of an issue, but length is. When length varies in shorter dimensions, the impact is far greater as we might have to reposition trailer crossmembers so that the floor ends on top of a crossmember and not in between two of them.

The same thing applies on our walls too. For instance, we have a wall made with plates of 52 inches, each time the plate ends, another plate is crossed over it by 1/2".
Each plate crossover is covered by a wall post for aesthethic reasons. Our Wall posts are 26" C/C from each other.

So what we do is there ares plate that have a different dimension so that we can use 52" as much as possible while also having the most joint hidden possible and what remains is "special" length plates to cover the rest.

When the width varies by less then an inch, we have the crossover vary so that we do not have to redo drawings. When it's higher in variation, we have to rebuild the entire wall pattern, be it plates or post position.

Are these products mostly one-offs? The project is designed, make one or two and then onto the next project? Or will this be made over and over for years as orders come in?

[Glenn Schroeder]

I guess I might have mispoken when I said changes in materials. What I meant, is that most of our components and designs are built around our standard plate dimensions and that when these are not in stock, we end up having to do changes, and those changes have impacts over the rest of the project.


Here's two concrete example, I can't provide pictures but I'm sure you can imagine what I mean.

The crossmembers of the example trailer are 12" apart from each other. Sometimes they vary by more or less then 2 inches, so that they do not cause conflict with other components. These are not problematic in terms of production.

Our floor is made with a sheet of 288" length x 96" width, which we either buy the correct dimensions or bigger and have the production cut it to the appropriate dimension.

Well, now we sometimes have to buy the plate with shorter dimensions, either width or length. Width isn't much of an issue, but length is. When length varies in shorter dimensions, the impact is far greater as we might have to reposition trailer crossmembers so that the floor ends on top of a crossmember and not in between two of them.

The same thing applies on our walls too. For instance, we have a wall made with plates of 52 inches, each time the plate ends, another plate is crossed over it by 1/2".
Each plate crossover is covered by a wall post for aesthethic reasons. Our Wall posts are 26" C/C from each other.

So what we do is there ares plate that have a different dimension so that we can use 52" as much as possible while also having the most joint hidden possible and what remains is "special" length plates to cover the rest.

When the width varies by less then an inch, we have the crossover vary so that we do not have to redo drawings. When it's higher in variation, we have to rebuild the entire wall pattern, be it plates or post position.

I understand the need to minimize labor and material costs (and weight), but in your first example would just adding an extra cross member to support the joint between the floor plates be a decent alternative? That way the normal spacing wouldn't need to be adjusted for those special circumstances.

[AlexLachance]

Are these products mostly one-offs? The project is designed, make one or two and then onto the next project? Or will this be made over and over for years as orders come in?

They will be made over and over with custom instances having certain variabilities dependant of the client in particular. We update these regularly because of:
Improvement suggested by client
Improvement suggested by production
Problem faced during production
Problem faced in the finishing stages of production. (Paint, wiring, installing stuff)
Problems faced over time with existing sold products.


Thankfully, the variabilities that are dependant of the client are generally not impacted by these "changes" that cause issues to us.

[AlexLachance]

I understand the need to minimize labor and material costs (and weight), but in your first example would just adding an extra cross member to support the joint between the floor plates be a decent alternative? That way the normal spacing wouldn't need to be adjusted for those special circumstances.

That could be an alternative, but it certainly would look weird for anyone noticing it in comparison to the rest of the trailer.

[zxys001]

They will be made over and over with custom instances having certain variabilities dependant of the client in particular. We update these regularly because of:
Improvement suggested by client
Improvement suggested by production
Problem faced during production
Problem faced in the finishing stages of production. (Paint, wiring, installing stuff)
Problems faced over time with existing sold products.


Thankfully, the variabilities that are dependant of the client are generally not impacted by these "changes" that cause issues to us.

I suggest being upfront with the client on the alternate configs per the material supply (sheet sizes) so they clearly understand when they sign off? Also, for the smaller sheets, have the sheets drive the cross beams to adjust/meet the seams?

[AlexLachance]

I suggest being upfront with the client on the alternate configs per the material supply (sheet sizes) so they clearly understand when they sign off?

I don't think that's possible, not that I'm really part of that whole process. Some clients can be very lenient, while others can be very strict, especially about aesthetics, so having things that can change visually to the client is not the best alternative.

Also, for the smaller sheets, have the sheets drive the cross beams to adjust/meet the seams?

That cannot be accomplished, there are unfortunately too many variables that affect these. Like, I actually managed to force some sort of "standard" of having 95% of the crossmembers placed at 12" C/C, but that standard comes at certain prices. Changing that standard comes at other prices, such as loss of efficiency in production.

[Frederick_Law]

Every lb added to material is a lb less the truck can carry.
That's why they hire skinny drivers ...... :p

If you quoted a certain size plate and it come it short, not much you can do.
If this happens alot, maybe order longer plate and trim it yourself. It add more work and cost but reduce headache and interuption.
Unless you have proven procedure to weld and lengthen any plate. We had procedure for most material. Even 10" thick plates.
One place I worked always machine all the edges. Much better fit and weld. Barrie Welding, Western Mechanical.

If every truck use different length plate, it'll be nightmare to keep track.

[AlexLachance]

Every lb added to material is a lb less the truck can carry.
That's why they hire skinny drivers ...... :p

If you quoted a certain size plate and it come it short, not much you can do.
If this happens alot, maybe order longer plate and trim it yourself. It add more work and cost but reduce headache and interuption.
Unless you have proven procedure to weld and lengthen any plate. We had procedure for most material. Even 10" thick plates.
One place I worked always machine all the edges. Much better fit and weld. Barrie Welding, Western Mechanical.

If every truck use different length plate, it'll be nightmare to keep track.

That's our current procedure, but even then it causes issues because the materials either come in late or with the wrong dimensions, and the shop wants to save the actual trim because we're also trying to increase our production ratio.

[Frederick_Law]

Looks the company need to bite the bullet and stock more standard size material.
At least for the time supply is a problem.
I understand material price changes by the minute now. So management need to decide when, how much to stock at what price.
Management, accounting, purchasing and production need to work together to get pass current difficult time.
Layout all the solutions and problems. Decide which problems everyone can live with. Pick solution accordingly.

[AlexLachance]

Looks the company need to bite the bullet and stock more standard size material.
At least for the time supply is a problem.
I understand material price changes by the minute now. So management need to decide when, how much to stock at what price.
Management, accounting, purchasing and production need to work together to get pass current difficult time.
Layout all the solutions and problems. Decide which problems everyone can live with. Pick solution accordingly.

Pretty much. I was hoping there would be a magical out-of-the-box solution to save us all these little hassles but figured these are the types of intangibles that can't really be controlled and must learn to deal with in time.

[Frederick_Law]

Need look at what the company can control. Use that to fix things it cannot control.
It'll be a long meeting. Order pizza and beer.

[Glenn Schroeder]

Pretty much. I was hoping there would be a magical out-of-the-box solution to save us all these little hassles but figured these are the types of intangibles that can't really be controlled and must learn to deal with in time.

Alex,

If this stuff was easy anyone could do it.

Glenn

[AlexLachance]

Alex,

If this stuff was easy anyone could do it.

Glenn

Indeed, but perhaps someone had done it already somewhere or had started thinking of something along that line. Sometimes, brainstorming like this can create new ideas/solutions much faster then by remaining alone with your own ideas.

[JSculley]

Indeed, but perhaps someone had done it already somewhere or had started thinking of something along that line. Sometimes, brainstorming like this can create new ideas/solutions much faster then by remaining alone with your own ideas.

It seems like the easiest solution to part of your problem is to try to remove the artificial restriction placed on you:

"We are asked to keep the welding to a minimum, when possible"

A submerged arc welding (SAW) machine would let you build up plates of whatever size you need from what you have on hand, and pretty quickly too (30lbs of weld per hour). It doesn't solve the thickness issue, but it seems that length/width is the larger issue. The metal hull of every ship on the planet was likely built this way using SAW.

[bnemec]

It seems like the easiest solution to part of your problem is to try to remove the artificial restriction placed on you:

"We are asked to keep the welding to a minimum, when possible"

A submerged arc welding (SAW) machine would let you build up plates of whatever size you need from what you have on hand, and pretty quickly too (30lbs of weld per hour). It doesn't solve the thickness issue, but it seems that length/width is the larger issue. The metal hull of every ship on the planet was likely built this way using SAW.

I was thinking similar with a jig seamer. I wasn't around SAW but we had a ~16' TIG seamer putting sheets of 304 or 316 together two shifts every day. SAW would have been sweeeet!

[AlexLachance]

I was thinking similar with a jig seamer. I wasn't around SAW but we had a ~16' TIG seamer putting sheets of 304 or 316 together two shifts every day. SAW would have been sweeeet!

We've created a jig seamer also, but things just keep falling out of place, so for every solution we find, we have to find an alternative to something else. Most likely we'll eventually run into a dead end and won't be able to accomodate things and will have to close the shop until we can get the required components/material...

[Ry-guy]

If you are a SW user, this really sounds like a DriveWorks solution. You can have a configuration sheet upfront indicate sizes and build from the values. You can also save the DW configuration and rerun in the future. I recall using DW to also calculate scrap, matl costs and weight. These calculations are then used to determine how to quote the customer for standard configurations and identify what products are truly customized vs configured.

[AlexLachance]

If you are a SW user, this really sounds like a DriveWorks solution. You can have a configuration sheet upfront indicate sizes and build from the values. You can also save the DW configuration and rerun in the future. I recall using DW to also calculate scrap, matl costs and weight. These calculations are then used to determine how to quote the customer for standard configurations and identify what products are truly customized vs configured.

I try to keep as far as away as anything that relies on Dassault to work, I have enough of SolidWorks.

Thanks for the suggestion though, that would indeed be a good application, though it would require quite the setup for something that is more of a temporary matter then permanent, even though the temporary is becoming rather extensive.