Manufacturing Method for Scissor Jack - Advice Requested

[cadstudent]

Hello Folks

I am designing a scissor Jack. Theorecticly I need to be taking it as far as mass production. 300 units per annum. I was thinking which means would be the best method of manufacture. I have already got a couple of 3D models going. I know I want to cut down the cost by having less machined parts. I have selected my material allready 2mm thk mild steel. folded or pressed. So does that mean my method of manufacture is extrusion. As the machined rod is bought in. I'm thinking that my components will need to have some machining required. I'm fairly sure that once there is one made it can be produced by machines alone this reducing the cost of wages.

Please can you give me some sound advice.

Kind regards

A Student.

 

[OldEngr63]

My Toyota has such a jack. It is made entirely of heavy sheet/light plate (about 2mm) that has been stamped, folded and assembled to form all of the arms. There are some holes that were probably punched in the stamping operation, may have later been drilled for location and size.

 

[Pkruse]

Here is how we would do this in the real world.

First, I’d be very much aware that Toyota makes these things in far greater quantity. 300 per year is a very small production rate, but a rate that I’ve often worked with in my career. They might jump at an opportunity to spend $100,000 in incremental tooling cost to save ten minutes per unit. You won’t.

Then I’d study the drawings and have a discussion with the designer. At this point, he/she can often make quick and easy changes that would reduce production costs.

Then I’d send the drawings out to my vendor shops for a preliminary evaluation. Each will suggest design changes that might make it easier to produce in their shops. Since each shop will be set up a little different, each may have different suggestions. Then it is time for another discussion with the designer to further finalize the design.

In all likelihood, assuming that this screw jack is designed for something like lifting a car and not for leveling major concrete and steel structure in the construction of a bridge, your main jack structure will be heavy sheet or plate steel. The material will be a compromise between what the guy with the sheet metal break and the guy with the heat treatment facility suggested. I’d try to find an alloy with sufficient strength that does not need to be heat treated.

Then I’d evaluate your design carefully to determine how many components in your assembly could be bought off the shelf from a catalog, and then welded or otherwise incorporated into your assembly. This may result in another discussion and design change.

I’d also be aware of the environment that your product will be operated and stored in, and select an appropriate corrosion controlled assembly. If used onboard a ship, I’d want to hot dip galvanize it. That may drive a material change, which might change how I was planning to form it. Otherwise, it would be some form of paint, so I’d also have a conversation with my paint supplier.