sprucegoose Posted September 5, 2004 Report Share Posted September 5, 2004 Well I finally got this modification on the road, and is it great! They look fantastic and stopping power is awsome! No more coments from the riders as there heads bob back and forth as we slow to a stop. That warpage problem was so anoying! It was a lot of fun too, and I am fortunate enough to have the software and machining center to do the cross-drilling of the rotors. Made a quick setup and machined them after work on Fri., and put it all together yesterday. Here are a few pics of the process and results. The first one here is the rotor I modeled up in Solidworks to figure out the pattern. You cannot drill thru the ribs, and have to stagger the holes so the entire pad surface is used equally. Those gray lines on the surface are the aprox. pad wear area... '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 Here is a picture of one of the rotors as I am drilling it on the CNC mill. I used a special 3-fluted carbide drill and then followed up with a small carbide corner radius milling cutter to round the edges of all the holes. I drilled through the first surface only, and then flipped them over and drilled from the other side. This way I could radius the other side with no alignment problems. I mirror-imaged the program at the machine control for the other rotor, so the pattern of holes is swept the opposite direction for the right vs. the left wheel... '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 This is when I flipped it over and drilled the outside surface. Found it worked better to not spot -drill the holes first... Saved time that way too, took about 11 minutes per side! '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 Here I am indicating to test for run-out of the rotor. The few nuts and washers are used to hold the rotor in place. '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 Here is a bunch of the stuff required to service the pads and calipers. The bushings (rubber grommets) were badly worn and sticking. This is what was causing a lot of heat build up and warpage. They need to be pulled out (usually won't come out in one piece!), and slide the new ones in with a little silicone grease. The pins were corroded pretty bad on the heads of the bolts, so I cleaned and polished them up as well. Threads may need to be cleaned up with a 11 x 1.5 die and re-tap the mounting holes to make it easier to thread the bolts back in. A small wire brush is very handy for cleaning inside caliper holes and rotor mounting faces... Assemble this with care not to get any grease on the braking surfaces, and use the brake cleaner spray if you do! '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 Here is a view on a freshly painted assembly. Love the look of that rotor with the silver and red! I used POR 20 silver paint on the caliper, and plasticote 500F engine paint of the back of the pads (masked off the pad surface) '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 And the final result with the wheels back on.... Sweet! I'll bet it looks good on the road with the wheels spinning too! I can't wait to do the same to the back wheels now! The best part of this whole project was I had so much fun doing it and it cost me only $9 for the bushings and $4 for a can of paint! (I had the silver from doin' the mufflers earlier..) '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
sprucegoose Posted September 5, 2004 Author Report Share Posted September 5, 2004 That's right, I forgot to add the $20 to resurface the rotors too! Well, that didn't exactly break the bank! I forgot to mention, I re-used the existing pads, until I buy buy a set of ceramic low dust ones... The pads had a ton of life left on them, but were definitely wearing crooked. So I redressed them flat and parallel on a disc sander, and vapor blasted the backs to prep for painting... '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
JasonA Posted September 5, 2004 Report Share Posted September 5, 2004 That looks great Dave! Nice looking wheels too. The only thing I don't like about my wheels is they hide the brakes too much. Oh well, I didn't get them for looks, I got them for stopping power, and they're super. I hope yours hold up! Great job! Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
adallak Posted September 5, 2004 Report Share Posted September 5, 2004 VERY GOOD JOB, SG! Could you please email me the SolidWorks file? I am going to do that too some day. The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
Ranger Posted September 5, 2004 Report Share Posted September 5, 2004 Nice job Dave. You did a great job on the pics and explanaitions. I loved it. It is worthy of an article in the "Machinist Workshop" or "Home Shop Machinist" magazines. You should submit it. I'm sure they'd love it. Link to comment Share on other sites More sharing options...
TDK Posted September 5, 2004 Report Share Posted September 5, 2004 A fine project considering engineering, aesthetics, planning, execution, documentation and of course budget. Have you estimated typical machining costs for someone without your skills and resources? For nitpickination, I did notice that the SoilidWorks file had 14-rows for all but the inside circle (missing on right hand side). Your pics do show all rows complete. For the fun of it, (geometry-heads anyway...) What might be the drill sizes proportional to each row's radius on the disc? What I mean is, to have the same ratio of swept-area to hole-area. IE: Smaller holes on the inside up the largest holes on the outside (just to complicate things). Again, Congratulations on your workmannship. Add power to leave problems behind. Most braking is just - poor planning. Link to comment Share on other sites More sharing options...
CaddyShack24 Posted September 5, 2004 Report Share Posted September 5, 2004 you're the man. 'nuff said Link to comment Share on other sites More sharing options...
sprucegoose Posted September 6, 2004 Author Report Share Posted September 6, 2004 Thanks guys for all the great compliments! I am so happy to have the Goose back in full braking form and looking good! Had a nice leasurely drive to the golf course with my son this afternoon and so nice not to feel that surging. Adallack, send me an eamil through the forum or give me your email somehow and I will be glad to send you the Solidworks file. It is fairly large, but I can strip the CAM (toolpath data) off it and probably get it down to 3MB or so? One thing to consider, and TDK kind of hit on it... The drilled pattern is really dependant on the make, model, and mfg. of the rotors as the can be quite different. I was originally planning on an exact duplicate of Jadcocks Powerstops, but his must have a different number of ribs, and you need to drill between them. Mine only had 41 (odd no.) and that is why the pattern could not be perfect. It is exactly like the solidworks model, missing one hole on the inner most circle. (just hard to spot in the picture as I rotated it down to the 8 o-clock position to be less obvious!) The most important part is symetry, and I have 41 holes, one through each web between the ribs. If you look at Jason's I think his had more ribs, and there was an even pattern all around. Wow... to increase to a larger hole on each outward bolt circle... That would really be tough to make it an even pattern! You have to consider the weight removal has to be as symetrical as possible to keep the assembly balanced, and the hole pattern has to stagger to permit even pad wear. I think you would have to develop some kind of algorithm to do that! That hurts my brain thinking about that!! Not real sure what it would cost you if you took you rotors to some custom shop and had them drill them. I guess if I was to estimate you would probably be looking at about $150-200, and you could buy a new set of those Powerstop rotors for a little more than that, and they would be nickel-cadmium plated too! Hmmm... "an article in the "Machinist Workshop" or "Home Shop Machinist" magazines" that's a pretty cool idea Larry, I might look into that! Thanks! '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
adallak Posted September 6, 2004 Report Share Posted September 6, 2004 Adallack, send me an eamil through the forum or give me your email somehow and I will be glad to send you the Solidworks file. It is fairly large, but I can strip the CAM (toolpath data) off it and probably get it down to 3MB or so? Dave, the related dxf or dwg with hole pattern are much smaller. I have provided you with my e-mail address. Thanks, Armen The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
sprucegoose Posted September 6, 2004 Author Report Share Posted September 6, 2004 Dave, the related dxf or dwg with hole pattern are much smaller. I have provided you with my e-mail address. Thanks, Armen Yes, that's true, they are much smaller in file size if a 2d layout is all you are looking for... But like I mentioned in the post, remember that each rotor mfg. may have a different layout for rib size, number, and rotor dia. consider! '09 Cadillac CTS-4 3.6 direct injection, 128 K mi. '15 Chevy Tahoe LTZ, 5.3i V8, 125 K mi '70 Firebird Formula 400, Bored+.04, RAIII heads, M21 4spd., in-process restoration! Link to comment Share on other sites More sharing options...
adallak Posted September 6, 2004 Report Share Posted September 6, 2004 Yes, that's true, they are much smaller in file size if a 2d layout is all you are looking for... But like I mentioned in the post, remember that each rotor mfg. may have a different layout for rib size, number, and rotor dia. consider! sure, I'll extrapolate to my rotors. I just want to understand the logic of the pattern (maybe improve). The saddest thing in life is wasted talent Link to comment Share on other sites More sharing options...
Ranger Posted September 6, 2004 Report Share Posted September 6, 2004 Hmmm... "an article in the "Machinist Workshop" or "Home Shop Machinist" magazines" that's a pretty cool idea Larry, I might look into that! Thanks! Dave, They are always looking for articles. If you are considering it, the "Machinist's Workshop" would be the more likely of the two since they usually have smaller projects. The "Home Shop Machinist" usually runs larger projects that span several issues. Link to comment Share on other sites More sharing options...
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