I've been tossing around the idea of modeling the major parts of an FD engine in either Pro/E, SolidEdge, or Unigraphics. I need information to do it.

I need either some scrapped parts (not far from PA) to borrow for measurements
or
models/drawings/sketchs that show dimensions.

I figure I'll need accurate key measurements, and I'll eyeball the size of other stuff based on photos and the parts diagrams.

Thanks.

Dave

 

Hey, if you could get me those models, and I can give them to our rapid prototyping guy and make them out of nylon! I could make a miniature 13B out of sintered nylon...

 

Exactly - that's the kind of nifty stuff that would be possible.

It would also be helpful to anyone who wants to check fits, plan an engine layout, consider swaps, etc. I'm sure the mod manufacturers have their own reverse-engineered models, but I understand that they cannot share them.

Dave

 

I was thinking some more:

Since these are parametric models, I could model them and send the information (crude drawings) with guessed dimensions. Then someone who has the part laying around could simply measure the part and send me the correct dimension values. It would only take 5-10 minutes. It would be very organized and easy to do.

Dave

 

Sounds like a cool idea. I'd help you out if I had a spare 13b laying around. I just remembered, I think we also have a process, using the rapid prototyping machine, to make parts out of a brass/steel mixture. Are you familiar with DTM? I think that's the name of the company. The parts are made by selective laser sintering of a polymeric material, in this case either nylon or a metal coated with a polymer.

 

My current industry has little use for RP, but a couple of years ago I had heard the metal sintering was advancing very quickly. My experience has been with traditional laser/thermoset RP. I remember hearing of a company that had a sintering-type process capable of fab'ing aluminum and steel of high strength and they were quickly bought up or exclusively contracted by a big automaker. It's cool stuff.

 

IT'S A REALLY COOL IDEA!!

But Why?

 

Because I enjoy it. I've done a lot of 3d modeling, and I'm proficient.

My last job was a CAD instructor, and in my current job I don't do much of it at all. We've got Unigraphics and SolidEdge installed here at work and I can pull down a license from home during off hours or lunchtime. I was going to start with the basic motor assembly (housings, rotors, shaft) and do the turbo assy and manifolds later.

Dave

 

It would be nice to have test fit motor to see if a 13b would fit into my geo metro.....muahahah

 

Hey, I'll bite: Why MUST the rotor housings be made from aluminum? Couldn't they be machined from steel or cast material to better match the thermal expansions of the side housings?

Or am I dense?

 

I don't know why Mazda chose AL rotor housings but here are a few thoughts.

AL conducts heat much better than cast iron or steel. AL is much lighter than cast iron or steel. Cast iron isn't really that stiff, steel is stiff of course.

I'm a Pro/E user. The problem with CAD models of motor parts is for them to be any good you'll really need some good measurements... Otherwise is is just for fun.

Good luck. Shoot me a PM if you want to share an IGES file(s) of it.

 

my asumptions they chose AL for weight reasons, and its esier to crome alluminum then steal. either way I duno but if you do make a cad rendering I highly suggest never letting the public see it and never make any models as selling cad drawings like that would go against the US Patent and would allow you to be sued.

 

Weight savings in an essentially hollow piece? Hmmmm... not real sure there. Easier to chrome... I might buy that. Heat conduction makes sense, but why not make the side housings Al as well, then? Durability? Why not the rotor housings then for similar reasons? I need to do more research, I guess. As far as stiffness is concerned, I was really just thining more along the lines of similarities of thermal expansion properties to reduce the O-rings walking around as much.

Perhaps it has to do with forging the rotor housings versus casting the side housings? Forging the Al is easier and cheaper (provided the rotor housings are actually forged and not cast, something I am not sure of...). Should probably ask this in the general section, huh?

Anyway, it was an idle thought... I LOVE post whoring!!!

 

OK Spurvo time to take over your hijack...

Haha, I know what you're saying because it could be considered reverse engineering of protected design data, but this is just for fun. In fact, it would take care of itself if anyone tried to misuse it because most of the dimensions would be phony (close, but phony). I'm not dumb enough to sell them - what gave you that idea?

Naturally I wouldn't be at risk of being sued if I was obviously not reverse-engineering it (for making money).

So does anyone have any engine parts laying who could donate a few minutes or let me borrow the parts?

Dave

 

I like the idea. Mazda wants a lot more of my gold for little parts. The rapid prototyping 3D printers are slowly getting better options on materials and colors. Or making molds for cheaper runs of a few more parts. Some of the items that are always getting broken on the third gen could be modified to have thicker dimensions and or tougher materials. Probably could ebay away a few of each.
I would measure parts on mine. Currently broken or missing: driver door bucket, inside opener surround, the trim around those pieces, missing Bose trim strips, hatch privacy hinge clip, glove box release handle, defroster outlet ducts in dash, dummy switch in center console, hood rod nesting clip, battery surround box, maybe a few more... Other things that could be easily enhanced for replacement?... wheel mini-hubs, door window trim triangle gizzies, license plate holder, turbo timer mounts, CD racks behind seats, ...
But I ramble.. first the broken parts.

 

take all the parts to a CMM and digitize it then convert it to whatever file it is you need to run it in a software..iges, dwg,etc......

 

You are about 100 miles away from KD Rotary.

My suggestion? Get your *** up, drive over to KD Rotary, and spend a few hours in their parts department

 

Hmm, I've been thinking about making a trip there just to visit, but b/c of their backlog I mentally wrote it off. I'm thinking I should do exactly that.

Dave

 

Have you ever done this before? It's a real bitch, and that's IF you have access to CMM equipment. Only a sales guy would make it sound so simple.

Besides, I'm more interested in the main engine components - not stuff that would be usable if reproduced as rapid prototypes.

And for the folks mentioning RPs - the cost of reproducing parts in RP is still probably a lot higher than buying OEM from Malloy. It would only make sense for scale models.

Dave

 

I dug around and found the parametric equation for an epitrochoid. Anyone know the constant values that produce the interior of the rotor housing?

Dave

 

From the Yamaguchi book it says;
Generating radius R 4.1in (105mm)
Eccentricity e 0.59in (15mm)
K Factor (R/e) 7.0

 

To feed the rapid prototyping animal,
what format(s) can be used?
Can something as simple as Activision's old CAD-3D be used? Is there an inexpensive common program that can be used, and then maybe convert the output? Or would we have to feed dimensions to someone who had the right software?

 

It would be fun to get a few toys, too.
Pretend rotors... adapted for doorknobs, drinking glasses, house slippers; rotor-head hats;

Eat your heart out cheese-heads!

 

They have two rotor housings sitting on a table just inside the front door. One has the rotor in it, the other is emtpy. Go at it w/a tape measure.