Loxxrider's 200 20v Revver: See you on "The Project Pad"

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 9:04 am

Does anyone know the bolt diameter thread pitch for the bolts that go from the caliper carriers to the strut housings?

I 'd like to know just so I can double check what I've got.

zerb · Post by **zerb** » Sat Jun 13, 2009 9:30 am

12x1.5x35 iirc

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 10:47 am

yep, i have m12x1.5

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 12:59 pm

and here is a rough draft of the design!

I can make it a lot prettier...but I'll have to see how much that adds to machining costs.

The holes on the vertical side of the bracket will be threaded. All dimensions are somewhat rough, but this was just to get the basic design down. It will take me like 5 more minutes to get it perfected once I can measure everything super accurately.

I also need to add a little cutout for the standard fit holes on the horizontal face to accommodate where that fillet is.

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 1:36 pm

andddddddddd

a rapid prototype lol

cuatrokoop · Post by **cuatrokoop** » Sat Jun 13, 2009 2:30 pm

Chris, just pick your alloy wisely and you'll be fine. I can't remember what alloy we went with for my CQ and a certain 90q12v Sport, but it doesn't even have any flash rust on it after sitting in a moist garage for almost 7 years. My interior will need LOTS of help though, of the anti-mold type :(

RS · Post by RS » Sat Jun 13, 2009 3:33 pm

Stainless is not the best for an application like this and will definitely add to the cost. Do yourself some math (mech-e, right?) and design for 1018 to 1040 steel making sure you have enough depth to get at least 2x thread engagement of your mounting bolts. Shouldn't be too bad. Base your fatigue life estimate on worst case, then go to town. PM with ?'s.

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 5:50 pm

Yeah...I don't think steel is going to happen with these. The guy that wants to machine them is not very cool with that idea...and I really don't blame him considering how hard it is.

I think its going to have to be just a high quality corrosion-resistant alloy of aluminum or bust. I think the thread engagement should be just fine with about a half inch worth of aluminum material to bolt to.

derrish_vulf · Post by **derrish_vulf** » Sat Jun 13, 2009 6:11 pm

very cool, what program are you using?? Id love to mess around with that!!

RS · Post by RS » Sat Jun 13, 2009 6:14 pm

Its not that bad to machine 1018 into the shape you've drawn unless he's got a teeny little mill-drill or something. Or is a wuss. For aluminum alloys, expect to spend your money in material. The issue is that most of the high strength aluminums (20xx) and (70xx) are not the best for corrosion. At the least consider doing a hard-coat anodize and teflon fill.

I'll bring up that most of those aluminum alloys will anneal at temperatures much above 300F but I'll leave it to you for a few moments to grasp that detail.

1/2" of aluminum is not enough for thread engagement. 12mm ~ 1/2" so you would have 1x thread engagement. Typically, 1.5x engagement is considered as strong as the bolt in tear-out if the materials are the same. As the aluminum is softer, you wouldn't get there. That would prevent reaching appropriate torque of a graded fastener as required to prevent it from backing out. I'd go to at least 1.5x diameter engagement and really consider doing a helicoil insert to reduce the tear-out potential.

I'm not trying to give you a real hard time, but brakes are kinda important. I've engineered caliper adapters before and it does take some thought.

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 6:36 pm

derrish_vulf wrote:very cool, what program are you using?? Id love to mess around with that!!

I'm using ProEngineer and I also mess around with SolidWorks. They are definitely fun to mess with, but the learning curve is steep unless you have someone teaching you. The price tag is also steep.

If you are new to CAD, then try out SolidWorks. Its the most user-friendly one I have come across.

RS wrote:Its not that bad to machine 1018 into the shape you've drawn unless he's got a teeny little mill-drill or something. Or is a wuss. For aluminum alloys, expect to spend your money in material. The issue is that most of the high strength aluminums (20xx) and (70xx) are not the best for corrosion. At the least consider doing a hard-coat anodize and teflon fill.

I'll bring up that most of those aluminum alloys will anneal at temperatures much above 300F but I'll leave it to you for a few moments to grasp that detail.

1/2" of aluminum is not enough for thread engagement. 12mm ~ 1/2" so you would have 1x thread engagement. Typically, 1.5x engagement is considered as strong as the bolt in tear-out if the materials are the same. As the aluminum is softer, you wouldn't get there. That would prevent reaching appropriate torque of a graded fastener as required to prevent it from backing out. I'd go to at least 1.5x diameter engagement and really consider doing a helicoil insert to reduce the tear-out potential.

I'm not trying to give you a real hard time, but brakes are kinda important. I've engineered caliper adapters before and it does take some thought.

Hey, I don't mind that you are "giving me a hard time"...on the contrary. I actually REALLY appreciate it. While I do know more than the average Joe about this stuff, I'm not scared to admit that compared to some users on here my knowledge is limited. Its all relative of course. So please do keep coming with the suggestions.

The guy who is going to be making them has a full on CNC shop to make these with...so its definitely no joke.

You have a much better grasp on materials than I do, and thats mostly because I have neglected taking that class so far. Its coming this semester though. The great thing is that I have access to some of the best minds in the country when it comes to machining, etc...so rest assured that I will be in contact with them before (if) any of this ever gets marketed in any way.

I definitely understand the thread engagement thing...but I dont know if that is even possible with this bracket...

Look at what Apikol has done with a similar bracket (they don't have one for UFO struts though). I am pretty sure this is aluminum (says Zinc plated for corrosion protection). There is definitely not a lot of thread engagement to be had there. So am I to conclude that steel is the only way to achieve a truly safe bracket?

RS · Post by RS » Sat Jun 13, 2009 6:49 pm

Zinc plating is usually done on steel. Aluminum gets anodize or hexavalent or irridite. I'd also gather its steel from the tool marks. Those polish out of aluminum in about 10 seconds, doubt someone with their shite together as well as Apikol would leave tooling marks in aluminum (stress risers!)

From the picture, it looks close to 1.5x thread engagement. Not ideal, but as you said, its probably all you get with the space you have available. Still, the ratio of ultimate strength of bolt to part is pretty high. Grade 8 140ksi, 1018 steel 70ksi max. Not counting on the bolt friction for restraint in the radial mount caliper, but you still need to mind reversing loads as the bolts are in single shear.

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 6:56 pm

Ah you know what...I just realized that you were taking those bolts to be M12. The M12 bolts are the ones that go into the strut housing. These holes I measured to be about .45 in. in diameter.

I haven't had a chance yet to take them out to see what size they really are though. So that at least helps with thread engagement.

So basically right now the big issue is the material. I'll shoot him an e-mail to see what he thinks of all of this.

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 7:00 pm

also...what about some kind of steel insert?

RS · Post by RS » Sat Jun 13, 2009 7:19 pm

I wouldn't do a sleeve press-fit insert, it would have to be flanged. Would probably take just about as much time to do as the whole piece from steel. A helicoil insert (steel) will gain you some strength by increasing the mean thread engagement diameter of the aluminum part, but you can do the math, its not 100%. Does help prevent thread damage from cyclical loading and bolt inserting though.

loxxrider · Post by **loxxrider** » Sat Jun 13, 2009 7:30 pm

Cool man, thanks for all your help...I'll definitely be going through all of the options I have to see whats the best combination of safety, cost, ease of machining, etc. Safety comes first obviously.

quattrofrog · Post by **quattrofrog** » Sat Jun 13, 2009 9:33 pm

I'd go with steel, find somebody else that WILL work with the material. I worked with Brendan at Apikol on my custom steel brackets. The end product of my measurement and test fit work wasn't cheap but it is exactly as I specified and the 996/B8 system I run works very well.

cuatrokoop · Post by **cuatrokoop** » Sat Jun 13, 2009 10:57 pm

I actually think my new ones are 1040, wasn't too tough to do. I never got them finish machined, so they are just a huge chunk of steel and heavy.

My original carriers were I think 7k series and corroded very fast. Should have been anodized but for some reason Todd didn't do that and I didn't realize or think to do it myself. They started with around .5" engagement and ended with less than 0.3".

loxxrider · Post by **loxxrider** » Sun Jun 14, 2009 7:28 am

quattrofrog wrote:I'd go with steel, find somebody else that WILL work with the material. I worked with Brendan at Apikol on my custom steel brackets. The end product of my measurement and test fit work wasn't cheap but it is exactly as I specified and the 996/B8 system I run works very well.

Wow, that sure is purdy. I like how they put your name there too. I actually talked to Brendan about this...but never about them making some. I will definitely look into it.

cuatrokoop wrote:I actually think my new ones are 1040, wasn't too tough to do. I never got them finish machined, so they are just a huge chunk of steel and heavy.

My original carriers were I think 7k series and corroded very fast. Should have been anodized but for some reason Todd didn't do that and I didn't realize or think to do it myself. They started with around .5" engagement and ended with less than 0.3".

ughhh thats scary. I have talked to the Apikol people...so maybe if the other guy doesn't want to do it they would be happy to take my measurements and add a product to their line.

loxxrider · Post by **loxxrider** » Sun Jun 14, 2009 9:15 am

my design has evolved (now that steel seems to be the only option)

quattrofrog · Post by **quattrofrog** » Sun Jun 14, 2009 12:20 pm

Why are the holes are not evenly distributed/spaced? The radial mount holes for the caliper are offset relative to the axial mount holes. Have you considered which bolt head type you are going to use for the axial mounting? I'm using some bolts with large flanged heads but you might have to use a socket head bolt.

Are you going to use studs/nuts for the radial mount or bolts?

loxxrider · Post by **loxxrider** » Sun Jun 14, 2009 4:01 pm

Well the reasoning behind the offset spacing is because the bracket I have to work with (for reference) for hole placement is done like that. I haven't had a chance to try them on the car to see if even spacing would affect anything. Obviously it would place the caliper in a different spot...but I'm sure thats not an issue.

Thats why this is not a final product. When I can figure that out, it will be symmetrical (as long as it can be).

For the bolts that go thru the caliper, I'll just be using bolts with an allen head. It seems that this is the stock hardware for the porsche calipers?

I am pretty sure I am using just a regular M12x1.5 bolt with the large flanged head for the strut bolts (like the ones in the Apikol bracket above).

I'm going to do some FEA on it too.

cuatrokoop · Post by **cuatrokoop** » Sun Jun 14, 2009 6:46 pm

What version of ProE are you on? Will it read a 2001 file? I still have my .prt file somewhere for my carriers, you can see what I had done up around 5 years ago for my Coupe (G60 struts, 993C2 calipers, 308x32mm Wilwood rotors, custom hats). Heck I think I have the hat files too. Not sure where, I think they are on my old tower that my mom is borrowing...

loxxrider · Post by **loxxrider** » Sun Jun 14, 2009 6:57 pm

ah that would be cool. I use the Wildfire 3 verison...so I have no idea if it will read those, but I can sure try!

That would definitely be cool to look at.

cuatrokoop · Post by **cuatrokoop** » Sun Jun 14, 2009 7:00 pm

I'm assuming you are using an EDU version of ProE, as was I, and that they still have that stupid industry vs education thing going on...