WMB88

Hello everyone,

Earlier this year I machined a set of J-56 brackets for a friend's '77 track build. I've picked up the project again as a way to improve my CNC skills and perfect the part. I am looking for someone from the community to provide design and machining feedback, ideally by fitting the part up to their car. I am located in Southern California, a bit north of LA and would prefer to work with someone locally but am willing to ship the part to you (I currently have a right hand prototype). I have attached pictures of my latest prototype which still needs refinement in some areas; primarily in terms of surface finish. If you're willing to collaborate on this part, I'm more than willing to machine a set for you in return for your feedback. Thank you for your consideration. I have attached pictures of my latest part as well as a shot of the left hand fitted to my friend's '77.

Thanks in advance for your help!

The13Bats

I have j56 front calipers on my 69 and while in in eustis florida and dont know how much i could help i do have interest in your item,

I would rather talk private,

Your pms are off so

The13bats@aol.com

407 496 8334 anytime and text is fine

69ttop502

Also an east coaster here, but definitely interested in a set!

Bill

Big2Bird

If you get set up, I would take two sets.
I am in Anaheim, but I am not quite sure what you need done.
PM me if that helps.

chazde3

I have a set of real J56 brackets I could use for comparison.

Attachment 48354736

MCMLXIX

I live in the valley in LA and would like to know more about this.
PM me.

TimAT

In the Midwest, I'm interested too!

TCracingCA

I have three sets- small spindle early, and large spindle late both real. And the third is a small spindle aluminum reproduction! So which ones are you producing!

Nowhere Man

are they heat treated? if not they could be to soft and could fail. could they not?

MCMLXIX

While the OP did not state the heat treat number most aluminum bar stock comes heat treated.
The most widely available is 6061 T6 or a variant of T6....
If it was not heat treated it would have been very apparent when it was machined.

chazde3

Says right in the title that it's made of 6061. 6061 would probably be fine for this application, but I'd personally go with 7075 if I were making them.

MCMLXIX

7075 is stronger but more prone to corrosion and may not be a better choice.

chazde3

True, but I would also likely have them anodized with takes care of the corrosion issue.

MCMLXIX

Anodizing will help but not eliminate the problem.

WMB88

Hi everyone,

I appreciate all the feedback! For those of you who requested PMs, I can't currently send PMs. I'm not sure if its related to me being a brand new member or not, I wasn't able to find anything in the FAQs. I have a message out to the Admins. As soon as I can send PMs I will.

[QUOTE=TCracingCA;1596391592]I have three sets- small spindle early, and large spindle late both real. And the third is a small spindle aluminum reproduction! So which ones are you producing!

To be totally honest, I am not sure exactly surer about the specific fitment issue you mentioned. We collaborated on the 3D model which he developed from pictures of original brackets. It fits my friend's '77 which has a Wilwood brake kit but it should also fit the stock caliper with the possibility of having to adjust the bolt lengths.

This was an oversight on my part which I should have mentioned in my original post, the material is 6061-T6.

I am planning on sticking with 6061-T6 for the moment and am actively looking at anodizing options. I am open to looking at 7075 or even steel if someone specifically requests it.

Thanks again for the feedback!

chazde3

Let me know if you need any measurements off an actual pair or even a nw model drawn up. I have solidworks and NX both available to me.

WMB88

Actually I would appreciate it if you took a look at this drawing. I'm primarily concerned about the hole sizes and spacing compared to the original part. Based on what I saw the last time I fit one up, I think I should go tighter on the holes but I'm not sure what the hole sizes are on an original part.

Thanks!

redvetracr

not the only difference but the major difference between 65-67 and 68-82 is the size of the two spindle bolts 65-67 takes a 7/16 bolt, 68+up 1/2 bolt

chazde3

I see some GD&T concerns right off the bat, but for what you are doing it is pretty close to correct. There would be a few changes that I would make on it. As for the size and spacing of the holes, I will grab my set of brackets this week from my parent's place and measure them out to see what I come up with and can redline your drawing with any changes I measured.

I would drop the .55 holes to .531, that's the standard clearance hole for a 1/2" bolt at my company.

WMB88

Thanks for the feedback!