Sheet Metal Manufacturing

[Johnny_5]

So we're in the process of having our sheet metal chassis manufactured, and we've been trying to get some quotes from a few different local places. And unfortunately we've only heard back from one so far, and we think it is a little pricey.

We aren't really too concerned by what means it is manufactured, it's really more a concern of the best price and lead time. Possibly the biggest laser cutting company is right down the road from us, but we never could get them to call us back.

I'm personally getting a little worried, mostly because it seems like we have some more big expenses coming up soon.

I've attached a 3D PDF of the frame assembly. If anyone could offer some advice on ways to approach the local shops differently, I'm all ears. And if anyone could just give me a ballpark of about how much it might cost to fabricate, that would also be great.

[Tom Line]

I will be frank with you. You're in a lot of trouble.

We're at the half way point in the season, and you guys don't have a supplier for your chassis. BEST case, you find a commercial sheet metal shop who is willing to make your parts. The small batch is going to be expensive, and you're not going to get 2 or 3 day turn around time. Then what happens if it doesn't fit together or isn't stiff enough, or some of your measurements are off? Do you have the raw materials, or are you assuming the sheet metal shop will have the correct thickness raw aluminum to bend?

I would strongly suggest re-evaluating your remaining time and looking at the many pre-made sheet metal chassis' you can purchase from places like AndyMark and vexpro. You could purchase one and have it driving around in under 4 days.

[Akash Rastogi]

Originally Posted by Tom Line

I will be frank with you. You're in a lot of trouble.

We're at the half way point in the season, and you guys don't have a supplier for your chassis. BEST case, you find a commercial sheet metal shop who is willing to make your parts. The small batch is going to be expensive, and you're not going to get 2 or 3 day turn around time. Then what happens if it doesn't fit together or isn't stiff enough, or some of your measurements are off? Do you have the raw materials, or are you assuming the sheet metal shop will have the correct thickness raw aluminum to bend?

I would strongly suggest re-evaluating your remaining time and looking at the many pre-made sheet metal chassis' you can purchase from places like AndyMark and vexpro. You could purchase one and have it driving around in under 4 days.

Going to echo Tom here. If you have not secured a sponsor or machine shop to do this for you before build season, you are wasting a lot of time.

If you are still keen on going this direction, stop calling the shop, visit them directly ASAP and explain your situation. Even then, I highly doubt they can do this for you quickly.

I would suggest the same as Tom - buy something from VEX or AndyMark and don't waste more time.

[Joe G.]

I would tend to agree with Tom, it's a bit late in the game to be getting this kind of thing squared away. However, if you really want to pursue a custom sheet metal chassis, here are some tips:

• Unique part count is the name of the game when it comes to sheet metal. The more you can use duplicate parts, the less it costs to produce, because programming of bends is a hefty portion of the labor involved. Do what you can to reduce the number of unique parts in your assembly. Why aren't the front and back rails identical? Same with the pieces across the bottom? Any chance that the drive rails themselves could be identical? These are the kinds of questions you need to ask. I have designed sheet metal chassis' that gave me everything I wanted with as few as two unique parts. The andymark C-Base is an example of a sheet metal chassis with one unique part.
• Similarly, the more you can standardize thicknesses, the better.
• One part that looks of particular concern is the main wheel module. Narrow, deep C-channels like that are very hard to bend. In general, you want a leg length shorter than the base width to ensure that no special tooling will be required.
• Work with the sheet metal supplier, don't just send them drawings and demand exactly what's pictured. For example, every shop will have a bend radius that they prefer to work with for a given thickness of metal, which you should design into each of your parts. There are many little ways that they'll be able to show you that can reduce costs.

[DonRotolo]

They are not calling you back, or quoting high prices, because you want only one. It is not worth their time and effort for a one-off like that.

Not to mention, now you get to see that this stuff is expensive. I coudn't open your PDF, but if it looks like a typical chassis, it might cost something around $500 for laser cutting and bending.

For that kind of money, get out the drills, metal shears and bending brakes and go wild...

[geomapguy]

Drive in a Day!

http://www.vexrobotics.com/vexpro/st...-in-a-day.html

That is all

[Joe G.]

Originally Posted by DonRotolo

They are not calling you back, or quoting high prices, because you want only one. It is not worth their time and effort for a one-off like that.

Related, find shops that specialize in prototyping, one-offs, and so on. They will be much better set up to handle FRC than a production facility which receives orders in quantities from hundreds to millions.

[Phyrxes]

Do you have any parents/family friends/mentors whose day job has them interacting with any of these places? Someone that already has a working relationship with such a company is much more likely to get any kind of response than a cold call/email.

Our primary machining sponsor could be classified as a "prototyping" shop that does sheet metal work for larger companies.

[Mr. Mike]

Johnny 5,
We are located just North of Dayton about a 1½ he from you. We have a 48 inch shear and a 32 inch box break. If that will help pm me.

[Johnny_5]

So I have good news.

The place that originally quoted us, gave us a price break to make 2 of these. And we have decided that's what we're going with, along with delivery by the end of the week.

So thanks to everyone who offered input and help. We are fortunate enough to be able to find someone who can do it for a reasonable cost and in a pretty short time.

[Phyrxes]

Glad you came to a resolution that didn't involve scrambling to build an different chassis.

[Tom Line]

Originally Posted by Johnny_5

So I have good news.

The place that originally quoted us, gave us a price break to make 2 of these. And we have decided that's what we're going with, along with delivery by the end of the week.

So thanks to everyone who offered input and help. We are fortunate enough to be able to find someone who can do it for a reasonable cost and in a pretty short time.

That is outstanding! Now make sure you form a relationship with them. Bring them your robot - do a demonstration. Show them your awards. Thank you profusely and let them know they made it all possible. Then sucker them into being a permanent sponsor!!!!!