mule car vs. protoype

[annafergusen1980]

Hi,

What does the terms "off tool" and "off process" mean? what is a mule car and what is its difference with protoype?

 

[CoryPad]

A mule car is a current vehicle that has been heavily modified with parts from a new design for testing and development purposes. A prototype is a pre-mass production vehicle of new design that is used for testing and development purposes.

Regards,

Cory

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[GregLocock]

Yup

Off-tool means that it is a part that is made on the production dies/tools, but not neccessarily at the production rate, and it may not meet the spec. That's what you'd use at your confirmation prototype build, typically.

Off-process is not a term I've heard before but random googling indicate sthat it is parts off the production tool, /and/ using the intended production process, and line rate etc. I don't know whether they'd be in spec, or if this is what you'd use to establish capability.



Cheers

Greg Locock

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[WGJ]

Greg - Off Process - as you say, it's a part produced:

-with the final tooling
-on the prescribed machine
-by the prescribed supplier
-to the prescribed manufacturing process
-at the production processing rate

Bill

 

[annafergusen1980]

Thank you guys for the info. But cory, talking about the mule car. What do you mean by heavily changing the base model. Does these changes include changes of body parts as well or it is just other systems like the engine, suspension...and if it includes body parts what do we do with the packaging because this car is usually built at the early stages of Product development process. And if it is only limited to engine and suspension...Then it should be for dynamic testing, right? Then how could we do the dynamic testings while we are having a wrong weight distribution...Then what types of tests can we perform at this stage?

//Cheers,

 

[GregLocock]

You make as many changes to a mule as you need to, to make it represenatitive for the tests you want. What a funny question.

For instance we routinely alter weights, CG height , and some panels, suspension geometry, spring rates, shocks, sta bars, steering racks for mules.



Cheers

Greg Locock

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[WGJ]

If you are using a 'mule' to validate body changes then you have to know whether the loads experienced by the 'new' parts are representative of service loading. These days, CAE can do a lot if you know what the service loading parameters are.

In my own experience, the term 'Mule' has only been applied to vehicle where the purpose of the body shell is to act as a vehicle to carry engine/transmission/suspension development actions. Hence the Mule just carries the parts.

Cutting and carving of the body to pacakge a new engine/transmission/suspension usually means that the body is not a valid tool for final body structure validation.


Bill

 

[GregLocock]

Agreed, I haven't seen a body mule. You /could/ meaningfully do it with a body on frame car though, for example.

Most mules are for ride and handling, roadloads, and powertrain/driveline work.

This thread hasn't mentioned bucks, which are stationary mules, used for packaging and interiors and so on.





Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[CoryPad]

I agree with Greg and Bill.

 

[WGJ]

annafergusen1980, can we take it that you are involved in a vehicle development programme in a professional way and this is your first experience of them?

I see you've also asked questions about 'Engine manufacturers' and 'Product planning in GM'.

Bill

 

[annafergusen1980]

That's right Greg, as far as I know we have four of these: CV (complete vehicle), mule, BIW or BIW+components and bucks to my knowledge bucks is just a section of a car and can be used for any type of appropriate testing not just packaging.

Thank you Bill for your comment on that "off-process" thing and I can see you are keeping my track from that product plannig thing which was for quite some time ago.

//Cheers,
Anna

 

[WGJ]

Come on anna, tell us what you're up to !

Bill

 

[drwebb]

What about mock-ups?

If you combine a mule and a buck for purposes of mock-up does it produce a muck-up???

 

[WGJ]

Sometimes it's a muck up. Sometimes it's worse.

Bill