Make vs. Buy

A lot of teams are sending in Add Item Requests for parts which are not necessary, because these parts are "made" parts. Section 3.12 of the Cost Rules explains the difference, that teams should cost certain parts as "made" even though they purchase or buy them. This is in an attempt to reduce complexity in cases where the competitive advantage of certain parts is very low and the volunteers would have to add many different versions of something for very little benefit for you, the students. For example there are many types of steering racks and almost none of them are used exactly as purchased. Most teams end up making many of the parts themselves. Rather than catalog many steering racks we designate these as "made" parts. So even if you buy a Stiletto steering rack if the Cost Tables list this as a "made" part you cost it as if you bought the aluminum yourself and machined it at a mill. Or any other legal way to cost it. If the rack housing is cast then you cost it as cast. In theory all parts of the car could be done this way but we didn't want you to have to take apart your dampers to reverse engineer them. And because it is hard to describe the differences between dampers and there is a lot of performance difference between them (even ones that are almost the same on paper) these are "bought" parts that we list by make and model. For teams that actually make their own dampers there is still a Student Built option.

This confusion is obviously caused by the Materials Table not being clear. To try to make this more clear we will be adding place holders to the table. For example "Steering Wheel (All Cost as Made)" will be inserted. If you see this you will know to cost your steering wheel as if you made it. For example stamp out the steel shape, drill some holes, wrap in foam and cover in leather.

Some parts are listed both ways. There might be ten different calipers listed one of which is "Student Built'. In this case you should use the caliper you bought unless you actually made it then use the "Student Built" option and include all the materials, processes, fasteners and tooling used to cost that caliper. For more information please read section C3.12.
So if the material includes "Student Built" then you know you can cost it as you made it (if you did). If the material includes "(All Cost as Made)" then you know you have to cost it as if you made it even if you bought it.
As of the evening of Feb 9 these items are the ones that should be cost as if you made them even if you bought them. Please see the Materials Table as this list will not be updated:

Brake Rotor (All Cost as Made)
Differential Housing (All Cost as Made)
Pulley (All Cost as Made)
Sprocket (All Cost as Made)
Fuel Rail (All Cost as Made)
Heat Exchanger Fan Shroud (All Cost as Made)
Muffler (All Cost as Made)
Mirror, Rear View, Housing (All Cost as Made)
Seat (All Cost as Made)
Steering Pinion (All Cost as Made)
Steering Rack Housing (All Cost as Made)
Steering Rack (All Cost as Made)
Steering Wheel, Quick Release (All Cost as Made)
Steering Wheel (All Cost as Made)
Throttle Body (All Cost as Made)

Again, if you see a part on this list don't send an Add Item Request, instead cost it as if you had made it from the materials from which it is made.

Questions? Email us! Help us improve the clarity of this rules section.

This message has been edited. Last edited by: Bill Riley,

Noticed that in the Materials table, the description/ comments for 'high performance' and 'ultra high performance' engines are back to front. Thought I'd bring it up to prevent teams getting tripped up on it at the event. (although it's pretty obvious to work out the error)

Your not the only one.. Thanks for the update on it though.. I too was getting concern, or for that matter thought i was just stupid and couldnt find it.

quote:

Originally posted by D Collins Jr:
Please pardon my ignorance if this is an extraordinarily simple question that I have missed the answer to. Where and when do I need to click to be able to get to the Access Application? I'm getting a little panicked because there's less than three weeks to do the report and it doesn't appear as though the application is ready. Is that something that will be released soon (or already is)?

We have a few questions about the ‘Excel Spreadsheet with Database Fields’.
(1) On the BOM tab what exactly do you mean by “The cost of assemlies on this chart should not include the cost of the parts in the assembly but only the materials, processes, fasteners and tooling in the assembly level.” Could you please go into further detail or provide a more thorough example on this topic?
(2) In your earlier post you said “The teams entered into the Virgina event should be costing their cars using the Cost Tables on the website and the Excel templates (or their own spreadsheets or tools). There is no requirement to use the new software for North America events in 2009. As soon as the software is deemed functional it will be rolled out to all teams.” Under the PART tab, there are specific things you ask for such as, area, length, density, etc. If we use our own tables is it necessary to follow your format?
(3) If we do have to use your excel spreadsheet format, could you please go into more detail on what is expected?

All fair questions. We are putting together a one page "expectations" document that should cover all this. I'll post when it's done and available on the website

Has somebody been able to sync with the server with the last database version? Also, Has somebody noticed that the car total (cost) does not match the parts cost?

We have yet to get our hands on the actual cost software to even get a feel for it. I developed some powerful spreadsheets and costing system back in December to take into account all of the cost table fields and new system SAE has provided. It seems to be working well for all of our members to enter in the necessary items for their parts. Hopefully it will be a simple migration to the cost software if it becomes available prior to Michigan.

A couple more questions Bill.
(1) How do we go about costing splining parts, for example axle shafts? I don't see a splining process in the processes table.

(2) Brake lines fittings as well as fuel lines and fittings, should we be waiting for the Aeroquip catalog items to be added even if we do not purchase from Aeroquip, otherwise should we be submitting AIR for these items from other suppliers?

(3) Heat treat and normalizing, per section 3.6.2.A of the rules, we do not cost these items correct?

(4) For our tube space frame, does SAE expect that we (a) assign part numbers to each tube that is in the space frame and then define the processes for each tube (cut, cope, weld prep, weld) such that the space frame itself is an assembly defined by the tube parts or (b) specify the total length of tube, total cuts, welds, etc for the space frame and use that to define our space frame cost so that the space frame is basically 1 part?

Thanks Bill.

(1) My expectation is that most splines would use the "Mill - Form Cutter" process on the process tables. If you are using a different process that you don't believe is represented please let me know. The thread forming on some stub shafts and other drivetrain parts that can't be captured by tapping a hole will be added, probably Monday.

(2) The Aeroquip catalog is going to be added as generic items so if you are using an AN fitting the price will be the same whether it is Aeroquip or not. If something isn't in the catalog or different from the catalog you should submit an AIR.

(3) Correct. These items do not need to be included for exactly the reason and rule cited.

(4) The rules do not require nor prefer one method over the other. My advice to you is to do the latter, option (b), make the frame "1 part", include all the tubing, cuts, welding, etc. under one part. I think this is more realistic and significantly less work for you. However, a drawing, screen capture or other document can and should be included to backup your numbers. For example you could include 56 tube end preps and then attach a pdf showing a spreadsheet of all the tubes in your frame (or simply print it and include it in the hard copy report).

Is the tooling table going to be posted? The current link is broken, and all my team members are asking about tooling and how it applies to their processes.

Thanks! I didn't know it was broken. It's been posted since November, not sure when the link broke, but it's fixed now. Please let me know if any other links aren't working.

When can we expect a finalized materials list for Virginia?

Bill,

How do we go about assigning Part #'s when using the "FCA_Inputs" template? Also is the suffix naming convention an abbreviation of the system it's in? So Brakes would be BR, Suspension SU, etc.

How do I cost using a hole saw to cut a hole in sheet metal? The hole diameter is larger than 2", but costing it as a "saw cut" seems way too expensive for about 5 seconds of power tool "drilling" (since I presumably need to cost the saw cut by the circumference of the hole).

1) For Virgina only (that means not Michigan or California) we will be announcing tomorrow an extension to the deadline for postmarked cost reports. The deadline will be March 9th. The official wording will be available on the SAE website and I will post a link from here and www.fsaeonline.com. This is due to delays on our side (the organizers). It will also contain an explanation of what you should send us (hard copy and optionally electronic).

2) The Cost report application is not yet available. Lots of you have been sending in emails, which is fair. The truth is we're finalizing the hard copy report outs and incorporating the Beta test feedback. Please, please please you should be costing your car using the Excel templates on the website as the software may not come out in time for the Virginia teams.

3) We got slammed with Add Item Requests. I will post an updated materials table tonight sometime but don't look for it to be complete with all Virginia AIR's before the end of the weekend.

4) To answer Brian McGreevy's question, the system abreviations are in Appendix C-3 on the website. The base numbers are assigned by the team and arbitrary. See also Appendix C-2 for more details.

5) To answer Matt Z's question about hole saw cuts, you could consider this milling based on the volume of the material removed. Just explain in the description that the "mill" is a hole saw. You could also use a punch if the metal is thin enough. I will look at adding hole saw cuts to the process table.

I will be adding a process called "Sheet metal saw cut" at $0.20 / cm that can be used for straight saw cuts or hole saw cuts. Cost hole saw cuts by circumference.

Hello, a few questions...

First, when costing suspension assembly, is that all lumped under, say, "Suspension Setup-Independent Susp. (per Corner)" @ $8.75/unit? what steps need to be shown? Or are we just talking alignment and the like?

Second, we run Weld three piece wheels, which are not specifically listed in the list. They are similarly priced to the Keisers, so would it be reasonable to use that price?

Third, we have an off the shelf differential, and housing. The list of that you posted lists those as made... Is this forever, or just for VIR pending an AIR? It's not a particularly simple part...

And finally, is there any way to have a formula for bearings (ball, needle etc) similar to the spherical bearing formula, or do you need an AIR for every specific bearing?

Thanks

In answer to your questions:

1) The suspension setup includes all adjustments necessary for that corner, so if include four of these you are set. We debated how much detail to go into on this (per adjustment link, per shim). In the end we decided simple is better as we can always increase the sophistication of the cost model for future years, but for now just use the correct adjustment per corner. Also note that there is a misc. adjustment for things like chain tension, etc.

2) If a manufacturer is listed you can't use that description unless you run that component. If the manufactureris "Any" then it applies to every manufacturer. It isn't okay to cost Weld wheels as Keizer. We need an AIR.

3) Diff housings are "made" parts which means instead of listing 100 differentials we are listing types of internals. You buy the internals off the table and then cost the housing as if you made it.

4) I've been working on the bearing cost model for months and suffice it to say it is elusive. I finally was able to develop one for needle bearings based on the AIR's we received for Virginia (had to check the correlation). For now other types of bearings needs AIR's and as soon as we "crack" the formulas for them they will be added in their more general form like rod ends. If you have an equation that works send it to us.

Additionally...

1)Does this mean that I can cost a corner's assembly cost as 8.75? (which would be awesome because of the number of parts I'm dealing with)

2) We're going to VIR... So I need to cost it as made? Quite frankly, I was really surprised that the Welds weren't there, as popular as they are... Can I send you an AIR for Virginia? or am I stuck with an "as made item" as I'm (and by I I mean we) also behind on the cost, though trying to match every example...

3) OK...

4) So I need to list a ball bearing as made for VIR then? I'll check to see if I can find a formula... guess it depends on brand, is it ok to base it just on INA/FAG?

Thanks

1) The $8.75 only include the "setup". That is setting camber, castor, toe, etc. The assembly labor uses the normal labor entries to assemble each part to the assembly and the assembly to the car...so sorry but it's going to be quite a bit more expensive to actually put the corner together. And the cost will be proportional to complexity just like we designed the rules to reflect.

2) If you didn't make the wheel you can't cost it as made. You have to submit an AIR for Virginia.

3)

4) I was a little bit kidding about formula because it's a lot of work and I have been trying to do it for a long time. Better submit your AIR's for your bearings. We may get them processed before the deadline but we may not...

Bill,

I had submitted this question to Kathleen McDonald at the beginning of this month, and apparently it's caught in limbo waiting on a response from the rules committee... That said, I was hoping you could shed some light on what we should do. The VIR deadline is rapidly approaching, and it'd be really great to have a little more insight:

> How do we cost student built electronic boards that are external to a
> commercial ECU?
>
> In our case, we have a number of custom Printed Circuit Boards that
> are connected via CAN and communicate with, but are not directly
> controlled by our MicroSquirt ECU. A couple are used to actuate
> motors for gear shifting and variable intake geometry, another is used
> for our dash / traction control unit, one is used for a our fusebox /
> battery controller, and a final one is used for cooling system
> control. While all of them sense the variable(s) they control, they
> do not strictly qualify as a "Sensor to CAN Converter - $25" as they
> operate largely independent of the ECU. Further, they wouldn't fall
> under the umbrella of a student built ECU because actual engine
> control is handled by the MicroSquirt.
>
> Additionally, non-traditional PTC fuses, microcontrollers, LEDs,
> rotary selectors, and non-character based LCD dot-matrix displays
> are used. PTC fuses are soldered components that are basically
> resistors and a distinctly different class from traditional automotive
> fuses. LEDs and other components on PCBs have essentially the same
> cost and packaging as resistors or capacitors, and (when embodied on
> a PCB) their separate costing seems outside the intention of the rules,
> which seem to imply standalone components. Also, a dot-matrix LCD can
> represent any size character, and as such there is some ambiguity as
> to how to cost it because we could basically say it shows one (large)
> character.
>
> Our actual cost for the units in question is under $50 each for the
> PCB and components plus less than an hour's worth of hand soldering.
> If they were to see an actual 1000 unit production run for the weekend
> autocross driver, we'd expect their total material and assembly cost
> to be well under $10 each. I assume we need to submit a AIR for each
> instance, but I feel it'd be more appropriate to have a "catch-all"
> cost for these electronics (given the breadth of possible components)
> , as there is for the student built ECU.