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Custom brackets, need outside help



D94r
01-11-2010, 10:50 PM
This thread is geard more towards Gadget since I know he has a functional CNC plasma table. But I'm making this public as I'll take all advice/help from anyone.


What I need is custom brackets made that will adapt a Mustang Cobra caliper onto the Ford Ranger spindle. It's a very simple bracket and design with no depth offsets for any of the holes. This bracket allows us Ranger guys to go from the measly 10.5"/11.28" rotor to the massive 13" Cobra rotors up front for improved braking.

Soooo, what I'm wondering is, if I can get the dimensions of these brackets along with creating a dimensional file of them for whatever software is used, can I get someone to cut me out a couple for mock-up on my truck (Gadget ? :grin:)?

These brackets are produced by a "company" in Canada, but their prices have gone through the roof since they started makeing them and have almost doubled in price, which is outrageous for what they are.

Of course I'd pay for the metal stock and your time (to a point, trying to keep this cheaper than the "company") for the one-off's for R&D. Then, if the test fitment is good cut you (whoever is willing) in on the production of these brackets.

I come on here asking you hobbiest in the hopes of finding a cheaper initial solution to getting some one-off's made instead for R&D instead of a local shop charging full shop rates (and there are no hobbiest local that I can find).

Since these are a uniform thickness (which I'd have to measure and determine) I don't know if it would be easier for a CNC mill or CNC plasma to cut out (I guess thickness and plasma cutter capability would be the key determining factor). The other company makes them of aluminum, but I would think steel could be substituted without any problems since the factory spindles are cast (iron or steel I'm not sure of though), so strength shouldn't be a problem.

Anyhow, to give you guys an idea of what needs to be made and the end goal for these brackets here are some pics.

If anyone is indeed interested in helping out, more finite details can be hashed out in PM.




Brackets themselves. The inner milled out material is not neccesary, its an aesthetic point to the brackets.
http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/bracket.jpg


Bracket mounted to the Ranger spindle.
http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/BracketonRangerspindle.jpg

http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/bracketmountedonRangerspindle.jpg



Bracket mounted to Ranger spindle, with Cobra caliper bracket mounted to bracket.
http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/bracketonRangerspindlewithcaliperbr.jpg


What we start with and what we end with for a comparison of final goal.
http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/RangerbrakeCobrawheel2.jpg


http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/RangerBrakeCobraWheel.jpg


http://i177.photobucket.com/albums/w239/D94R/Turbo%20Ranger/CobraBrakeSaleenWheel.jpg

BearNPum
01-11-2010, 11:35 PM
It is going to take a pretty decent plasma cutter (as in amps) to cut steel that thick cleanly. I don't think the plasma cut is going to come out very clean in comparison. Would be worth a try though if someone wants to attempt it. Wish I had a CNC machining center to help you out.

D94r
01-12-2010, 12:00 AM
Yah, that's my worry too. I'd have to mock up a few things to get a measurement, but I'm guessing the bracket is around 5/8" thick. I have a buddy across the country who has a laser cutter at work who I've contacted about possibly helping out as well.

Push come to shove I can use the 4" grinder to cut out the rough shape of these brackets, then round out the corners carefully. But good lord that would take a lot of patience and make a hell of a mess.

Hamstn
01-12-2010, 05:55 AM
A lot of the cost in making those as pictured is for the "bling" factor. For doing that on the cheap I would go with a piece of 1/4" steel. Cut it out with plasma or O/A , smooth out, tap the holes (hard to see if they are or not), then if needed at the caliper bracket cut spacers or add washers to get your 5/8" spacing. Maybe better yet but a bit harder is 1/2" steel which would be near enough to 5/8" for your spacing. Steel would be stronger then the AL but much heavier.

Another idea would be to use AL but cut it out with a jig saw and drill holes with a press. Take some time and not be as pretty, but?

D94r
01-12-2010, 07:27 AM
Yah, I totally realize that a lot of the cost is for the "bling". The guy needs to make a profit, but he's gone astronomical on the prices (these brackets are part of a kit, but still for what you get in the kit it's way overpriced).

The one hole is tapped, the rest are pass through.

I'm not too keen on the washer as a spacer idea, but I have tossed around the idea of making steel standoffs and welding to the bracket to get the proper width. Ideally though I'd rather this be one solid piece.

I have plenty of time to formulate a solution, so we'll see what goes down.




On further research into these brackets, it turns out they are 3/4" thick. That is going to take one hell of a plasma to cleanly cut that. I know my LP50 is rated for 3/4", I just dont have a steady enough hand for perfect perpendicular cuts through the metal, nor a CNC table.

BearNPum
01-12-2010, 09:11 AM
If you didn't mind it being a bit rough, and could drill the holes yourself, I think a CNC like Gadget's would have a shot at getting a rough blank that would be usable. Hamstn's idea of 2 thinner plates with spacers is a good plan as well.

Depending on how nutty they have gone with the price, you may be able to have a local machine shop do these for less money.

Gadget
01-12-2010, 10:35 AM
I think the thickness is going to be critical since the bracket has to hang centered on the rotors so that can't change. 3/4" thick steel is thicker than anything I have cut on my CNC, 1/4" has been the max so far. I suspect you will get some beveling of the cut on a piece that thick. I certainly wouldn't try to cut the bolt holes with the plasma. You also won't want to pierce cut this piece either, 3/4" pierce is a lot to ask. You would have to start at the edge and cut into the piece from there.
And then we get to the biggest issue to me, that of liability for producing a part so critical to the safety of a vehicle. I probably could rough cut one but don't think I want to put myself at risk for the liability that might create. Part of the cost of the commercial units is for liability insurance I'm sure, and justifiably so.
As purely a hobbiest, I will have to pass on this the potential liability is too great for me.
Sorry,
Dan

bhardy501
01-12-2010, 01:25 PM
How about a water jet machine, anyone near you have one that could price doing them. They could cut bunches out of a peice of 4x8 ft. how ever thick and leave a very nice workable finish.

D94r
01-12-2010, 09:00 PM
If you didn't mind it being a bit rough, and could drill the holes yourself, I think a CNC like Gadget's would have a shot at getting a rough blank that would be usable. Hamstn's idea of 2 thinner plates with spacers is a good plan as well.

Depending on how nutty they have gone with the price, you may be able to have a local machine shop do these for less money.

You know, I didn't read Hamstn's idea as "two thinner plates with spacers", but now that you put it that way, two 1/4" pieces sandwiching a 1/4 spacer, then all welded could indeed work.... my only concern would be welding of the inner side of the spacers to the plates. This could be done if the center of the bracket was cut out on atleast one of the brackets though.



I think the thickness is going to be critical since the bracket has to hang centered on the rotors so that can't change. 3/4" thick steel is thicker than anything I have cut on my CNC, 1/4" has been the max so far. I suspect you will get some beveling of the cut on a piece that thick. I certainly wouldn't try to cut the bolt holes with the plasma. You also won't want to pierce cut this piece either, 3/4" pierce is a lot to ask. You would have to start at the edge and cut into the piece from there.
And then we get to the biggest issue to me, that of liability for producing a part so critical to the safety of a vehicle. I probably could rough cut one but don't think I want to put myself at risk for the liability that might create. Part of the cost of the commercial units is for liability insurance I'm sure, and justifiably so.
As purely a hobbiest, I will have to pass on this the potential liability is too great for me.
Sorry,
Dan

Yes, I feared beveled cuts too for material this thick.

Holes would not need to be cut, just the outside edges of the bracket itself. Holes would be drilled by me in a press.

As for liability I totally understand. But really what I'm wanting right now is just a mock up piece that wouldn't be used for anything else. A final piece would be copied from that for actual road use. This would be purely for mock up to make sure all the critical dimensions are correct.

FWI, the guy produces these on the side, so liability insurance isn't a factor at all through him.

Besides, you'd only be cutting out a rough shape in metal. What someone uses that peice of metal for is their own business... right? 8-)


Anyhow, I might give the 1/4" plate + 1/4" spacer + 1/4" plate a try for the mockup piece. That would make it the appropriate thickness and I'd only have to use a peice of 1/4" stock.

My buddy said if I can get him a CAD drawing of the peice he can laser cut it too for the final product. I just need to make the initial bracket, then measure and draw it out in CAD.

bhardy501
01-12-2010, 09:39 PM
Another idea would be to make 2 1/4 plates and a 3/4 in spacer. drill your plates out so the spacer would dropp all the way through. bevel the inside of the holes so you can weld them up from the out side and not have to worry about trying to weld on the inside. You would have to build a jig to hold them for welding.

D94r
01-12-2010, 09:59 PM
I assume you mean making the spacer the same part where the bolts go through? This would require extra wide area's around the bolts for 100% encapsulation around the spacer with the bracket. Would make for too much material and run into interference issues with the spindle mount.

Hamstn
01-13-2010, 06:34 AM
bhardy501 has a great idea and I was thinking of this as a way to build it but it is hard to put into words. The only hard part is the one spacer that would need to be tapped unless you got lucky to find one with the proper ID or had enough room for a nut on the outside. Maybe mill/drill the center out to fit in a grade 8 nut that has been rounded off and then welded inside the spacer.

Use the thickest walled pipe (I have some that is 1/4" walled not sure if it is called pipe), you can find, bolt to caliper, and then cut two 1/4 pieces of plate to fit both sides of the spacers, with spacers through the plate. You only would need to go around half way if clearance was a problem. weld outside and inside of each plate where it meets the spacers then grind down the outsides to fit flush with the caliper and spindle.

Now it wounds like you are looking just to built a mockup piece to use as a guild? Just use a piece of cardboard or sheet metal and then take your measurements to enter into PC?....just add the thickness to final measurments.

D94r
01-13-2010, 07:08 AM
Now it wounds like you are looking just to built a mockup piece to use as a guild? Just use a piece of cardboard or sheet metal and then take your measurements to enter into PC?....just add the thickness to final measurments.

Well, I need it to be able to support the weight of the caliper and hold it the proper distance off the rotor so I can confirm dimensions of the holes. Call it the anal retentive engineer in me :mrgreen:

Gadget
01-13-2010, 11:09 AM
I would think that 3/8ths thick steel would be as strong as 3/4" aluminum so you could use that as a blank. Then get or make 3/4" thick bosses for the bolt holes. The holes in the blank would be large enough for the bosses to fit through. Center the blank on the bosses and weld both sides. Actually, if you are only doing a mock up, 1/4 inch blank would probably be thick enough to hold things and much easier to shape.

frijoli
01-14-2010, 03:48 AM
How about a water jet machine, anyone near you have one that could price doing them. They could cut bunches out of a peice of 4x8 ft. how ever thick and leave a very nice workable finish.

This is the way to go if you want multiple copies. We have used water jet cut parts over 2" thick in aluminum. The outside finish looks like a light beadblast.

Clay

---------- Post added at 05:48 AM ---------- Previous post was at 05:44 AM ----------


I would think that 3/8ths thick steel would be as strong as 3/4" aluminum so you could use that as a blank. Then get or make 3/4" thick bosses for the bolt holes. The holes in the blank would be large enough for the bosses to fit through. Center the blank on the bosses and weld both sides. Actually, if you are only doing a mock up, 1/4 inch blank would probably be thick enough to hold things and much easier to shape.

Without actually doing an analysis, we always use the double it rule for mild steel and 6061-T6 aluminum. This typically save about 30% in weight. This is a rough estimate.
Keep in mind, stuctural strength in these material is different, and if there are any safety risks involved, DO THE MATH!

Clay

bradler451
01-14-2010, 10:34 AM
Looks doable they used to have a water jet machine cut things like this bracket at the local tech school pretty neat

D94r
01-15-2010, 07:46 AM
Well, me and a couple guys on the Ranger forums have been discussing this, and we may be taking another approach. With all the extra modifications needed to run the 13" Cobra brakes (I haven't told you about since for now I was only focusing on the bracket) it would be much easier to run the 12" newer Ranger rotor setup.

This would only require a bracket that is much easier to design. And since there's no extra mods required (because bearings, calipers, and such haven't changed since 1995) this would seems like the better and more feasable route to go.


Oddly, it also seems (without stop-pad proof) that the 12" setup will perform better since the Ranger calipers have the same number of pistons, yet they are bigger than the Cobra's. The brake pads have more surface area, and the radial difference between the two rotors is only .5", which I don't think would show any appreciable stopping difference if all things were equal.



We'll see. Maybe I'll still pursue the Cobra bracket though as a personal objective.

Bikespot
01-16-2010, 06:33 PM
These brackets can be made on a cnc mill. Doesn't matter the thickness , unless you have some powerless cnc mill. Dont have one so cant help you out there. Plasma would be an option to rough out the part. Then take a file or a grinder to finish size. Holes can be drilled once you find the right location.

I took a look at what you wrote again , those parts arnt that hard to make. Sorry i dont read every single post on here , but if you have a plasma i would rough out the part with it then just file/grind the rest. For the holes mock it up to find where you need the holes , then drill them out. It wont look anywhere as good as those parts but it will work.

Uncle Ed
01-17-2010, 01:20 PM
I wonder how much heat would be transferred through that piece. The pockets machined into those bought pieces may not be there only to safe weight and look snazzy. They may be providing more surface area and air turbulence for cooling the part.

D94r
01-17-2010, 07:29 PM
I think for the time being we are going to go the 12" rotor route, much simpler, but not as "cool".

As for heat through the bracket. I'd assume not much actually. On a road truck that see's daily driving there wouldn't be much heat generated. Typically you can touch the caliper after hard stops and they are warm/hot, but not enough to burn you (the rotor is a different story). So after heat transfer from the pads through the caliper I'm betting the bracket itself isn't seeing much heat at all.

Now if the truck is doing autocross or road racing that's a different story and the heat transfer would indeed heat up the brackets a lot more. But, I'd assume if the pockets were designed for that reason, he would have machined fins into it for added cooling surface area.

Uncle Ed
01-17-2010, 10:09 PM
I though of that but wondered if fins would collect mud and crud making a thermal blanket. either way I see your point. It would have to be driven pretty hard to transfer that much heat.

Another thing got me curious. In the pics you posted, the brackets appear to be fastened with bolts tapped into the brackets but the brackets show no threads. If they are countersunk allen bolts I don't see a shoulder in the brackets and that would weaken the attachment, anyway.

How are they fastened?

D94r
01-18-2010, 03:26 AM
The top hole of the bracket is a through hole. Bolt goes through Caliper, through bracket, then screws into the spindle hole threads.

Very bottom one is the same way. Only the caliper doesn't bolt to that hole. So the bolt just passes through the bracket and bolts to the spindle.

The outside hole is indeed tapped. The bolt goes through the caliper and bolts to the bracket.