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torker
03-11-2005, 11:12 PM
Guy built his own minature blown alky engine! Make sure to check out the video! Makes me want to go down to the shop and fire up my old Rodeck!
http://www.weberprecision.com/
Russ

ibewgypsie
03-11-2005, 11:22 PM
Well, He has more time than I do for the "shop"..

Geeze, don't know whether to be awed or jealous.

David

torker
03-12-2005, 12:41 AM
David...You said it! Geez, I just can't imagine the time it took him to make that. Be a cool lil motor for a Junior Dragster...all the other kids would want one! Probably sell for $4 million http://bbs.homeshopmachinist.net//biggrin.gif
Russ
(BTW, David, how is the drywall/pain in the butt carpentry coming along?)

BillH
03-12-2005, 01:03 AM
Rather pathetic blip on the throttle, I want to hear that thing roar!

torker
03-12-2005, 01:09 AM
Bill, I thought the same thing til I read that little bugger will spin 12000 rpm! Bet he doesn't think it'd last long buzzing like that.

hammerhead74000
03-12-2005, 02:01 AM
Nice! http://bbs.homeshopmachinist.net//biggrin.gif

Thought about doing that... decided to persue a Wankle instead - hence the design of my CNC software (it's got a bunch of math-derived curves, like involute and epitrochoid paths built in, in addition to linear circular/helical and nurbs curves).

Yeah, I bet that'd be a fun thing to have in the middle of a go-cart! http://bbs.homeshopmachinist.net//eek.gif

3 Phase Lightbulb
03-12-2005, 03:14 AM
<font face="Verdana, Arial" size="2">Originally posted by hammerhead74000:
Nice! http://bbs.homeshopmachinist.net//biggrin.gif

Thought about doing that... decided to persue a Wankle instead - hence the design of my CNC software (it's got a bunch of math-derived curves, like involute and epitrochoid paths built in, in addition to linear circular/helical and nurbs curves).

Yeah, I bet that'd be a fun thing to have in the middle of a go-cart! http://bbs.homeshopmachinist.net//eek.gif </font>

The middle? That would hurt like hell! I have mine off to the side http://bbs.homeshopmachinist.net//smile.gif

http://www.gnuxtools.com/psychokart/dscn2393.jpg

-3Ph

hammerhead74000
03-12-2005, 03:30 AM
Middle, as in mid-engine, not front engine (like most cars) or rear engine (like a 911 or bug).

Oh, and doesn't that thing have some odd balance related handling due to the placement of the engine and driver? http://bbs.homeshopmachinist.net//confused.gif

JRouche
03-12-2005, 04:16 AM
<font face="Verdana, Arial" size="2">Originally posted by hammerhead74000:
- hence the design of my CNC software (it's got a bunch of math-derived curves, like involute and epitrochoid paths built in, in addition to linear circular/helical and nurbs curves). </font>

Please post your code or email it directly, I am very interested! JRouche

hammerhead74000
03-12-2005, 02:43 PM
JRouche -

When I'm done with it, it will be available in an affordable way (I am thinking about bringing it out as a commercial product, but with a version geared towards garage shops - shareware, perhaps - and folks who have helped me will get a free license). I am also going to be promoting it's programming language as a new standard for machine control. I haven't decided how much of it will be open-source, though - but some code definitely will be, as an aid for others to create their own control programs that follow the standard.

Unlike most CNC's out there now, it's not EIA-274 (G-code) based. Instead, I went back, and examined all of the past programming languages, Pascal, C, C++, Objective-C, Forth, Postscript, assembler (several variants), and yes, even BASIC - and came up with something new, geared specifically for this task.

The result resembles a cross between C and PostScript, with a bit of SIMD assembler flavor thrown in - it's block-structured, stack-oriented, and has a vector stack for doing point calculations. There are no line numbers, operations are human-readable without special training (to do a rapid move, you just say rapid, not G0), and code is structured for readability. Also, the system has string handling functionality (intended for use with engraving operations, and communication with external devices/programs.) Local variables are de-marked with a colon (:myVar) and have independent real, integer, and vector aspects.

My implementation of this language is semi-compiled - the compiler generates a linked-list of objects that correspond to the operations called out in the source code. Executing a program is just a matter of calling the execute method of the objects in the proper sequence. The advantage of this is speed - it's fast enough that you can define your own curve types in user code as a procedure, without having to edit the CNC's program itself. This allows a CAD/CAM program to include new curves - or other stuff - in the program header, without having to have a new CNC, and without approximating it with linear moves.

An example of a procedure written in my language would look like this (not that this procedure is particularly useful - or the best way to do this - but it will serve to show the idea). Comments are delineated with a # character, and run until the end of the line.

rapidToAPointOnZeroZ # This is the procedure name
:myX :myY # Local variable declarations
{
:=myX.r :=myY.r; # First assigns the top of the real stack to the real aspect of :myX,
# then does the same to :myY
:myX.r x # Pushes the real aspect of :myX, and then
# moves it to the x component of the vector register.
:myY.r y 0.0 z rapid; # Does the same for y, and z (with zero) and then executes a rapid move.
};


More typically, though, a part program would look like this:

millASquare
{
retract 10.0 feed 7500.0 speed spindleon coolanton;
0.0 x 0.0 y 1.0 z rapid;
0.1 z rapid;
-0.25 z linear;
1.0 x linear;
1.0 y linear;
0.0 x linear;
0.0 y linear;
retract spindleoff coolantoff;
};

hammerhead74000
03-12-2005, 02:47 PM
Hmm - looks like the BBS killed my indentations - the code in the brackets { } is supposed to be indented.

Paul Gauthier
03-12-2005, 05:22 PM
Someone please correct me if I am wrong. But an 8 cylinder engine with a bore of 1.00" and a stroke of .900" should give a displacement of 22.619 cubic inches not 5.655 cubic inches.
Am I right or not.????

------------------
Paul G.

[This message has been edited by Paul Gauthier (edited 03-12-2005).]

tryp
03-12-2005, 05:46 PM
Swept displacement is 5.655 each cyl is ~3/4 of a CI

.5^2*pi*.9*8cyl= 5.655

cliff69
03-12-2005, 06:07 PM
Cool...

Paul Gauthier
03-12-2005, 10:27 PM
Ok now I got, was having a blond moment.

PhilR
03-13-2005, 11:18 AM
Very nice!
Would an oil ring actually be needed for that small of a bore? Also curious why the oil rings are thicker than the compression rings?


[This message has been edited by PhilR (edited 03-13-2005).]

KENZ
03-14-2005, 10:08 AM
I realize that it probably wouldn't get run for long periods of time, but I wonder if it would need a harmonic balancer if it was used for anything but drag motor?

torker
03-16-2005, 08:29 AM
Ken, There are many hi performance roots style blower engines out there that don't use a harmonic balancer. The blower belt itself absorbs the harmonics. The ONLY time I ever had trouble with a blower drive setup was when I did use an ordinary harmonic balancer. This was a motor that I'd just bought and was in a hurry to use it. The balancer cracked nearly in half and could have exploded(now I know why they are banned from competiton engines). I was really lucky that it didn't end up hitting someone. My present competition engine does in fact have a "balancer". This is an older Fischer unit made for blown alcohol engines that has stood up very well but I'm the only one who uses this type of setup on our whole circuit. If I keep the motor I'll be getting rid of the balancer and building a crank snout girdle for it. Too hard to mount one with the balancer in place.
Russ

KENZ
03-16-2005, 10:27 AM
torker,

I thought I had read something a long time ago that the blower belt dampened the vibrations but I wasn't sure, so thanks for setting that straight.

What circuit do you race on? What kind of car do you have? My boss has a car that we take to track on some weekends. Usually just to the test and tune sessions to have some fun. It's not blown though- the transmission is at the monent though. The guts of the torque converter let loose and all kinds of metal went through the tranny. He has it at a friends house who is rebuilding it for him and a new torque converter on the way.

BTW- my boss is a MOPAR guy
I can never remember the model of the car, I'm more into 4x4s; anyway it's a 1964 Chrysler something.
500 C.I. wedge motor in it
Never entered it in a competition since he's had it- I think it could be entered in the Sports Comp class- Too stripped to go into the nostalgia(sp?)class.

torker
03-16-2005, 09:32 PM
Ken....I run in the mud. Compete in the Pro Class, blown alky on paddles. Engine is an all aluminum 572 ci Rodeck with a 14-71 Kuhl hi-helix retrofit blower and Enderle "Bird". With a freshened blower making around 37 lbs of boost it makes around 1800hp on a fairly safe tuneup.
http://img.photobucket.com/albums/v210/torker/Mvc-298sHairy_Kanary.jpg
Russ

jburstein
03-16-2005, 09:39 PM
That...uh...looks like a good way to get dirty.

Is it like mud drag racing, or more like those dirt oval circuits?

torker
03-16-2005, 09:55 PM
Yup...you get dirty if you make a bad run. It is like drag racing...200ft long pit. From a standing start a decent run is about 2.8 to 3.0 seconds.
Russ

KENZ
03-17-2005, 10:08 AM
That is a sweet setup. http://bbs.homeshopmachinist.net//smile.gif Thanks for sharing the pic. There is nothing better than going to a mud bog. I've been addicted to the mud since I was little. There is just something about playing in the mud that makes you http://bbs.homeshopmachinist.net//biggrin.gif

Right now my old jeep does dual duty, but plans are in the future to make it a a full time play rig.
Thanks again
Ken

Elninio
03-19-2005, 07:05 PM
quite a shop hes got there