[dataway]

Pictures really do help.

I should be able to make those changes without serious problems, I think.

So the LARGE fins/crosses on the supports need to be 0.16" tall from the back of the plate?
And the small locating lugs don't fit into the radio holes?
What is the diameter of the radio holes?

Are we sure there are no differences between the 70-77 models? Same radios and bezels fit in all those years?

That lower radius bothers me ... that one you have now is based on a very accurate trace of a 70-77 radio bezel. Are we sure that the OEM part tracked the radius of the dash pad that closely? Dash pads aren't particularly uniform in their dimensions. If I change the lower radius it is NOT going to the be same as the OEM radio bezel.

Anyone have any close up photos of how their radio bezels fit in those corners?

One problem here is as the stand-off height changes, the dimensions of the hole the entire plate fits in will change (again the funnel scenario). For instance if I shorten the supports to 0.16" ... it will fit father into the dash pad hole ... where the dash pad hole will be smaller .... will the 1/16" reduction in height and width accommodate that?

In the final analysis though, the objective is to make one that fits YOUR car.

[dataway]

I've created revised files, while retaining the originals.

The lower corner radius on the OEM radio bezels is 0.625, changed our plate to 0.75"
(bear in mind that the hard plastic parts are a fixed dimension, while dash pads shrink and change shape as the years go by, so I am keeping the original files also, in case we find that those corners are not uniform car to car)

Reduced total height and width 1/16"

Reduced the large fins on the supports from 0.30" to 0.16" (I am thinking about doing away with the locating lugs, I think they are causing more problems and confusion than they are worth. Is the 0.16" fin height based on those lugs NOT fitting into the radio holes? If so, then the height of the large fins needs to be slightly more than 0.16" )

Trying to decide whether to reduce the length of the attaching posts .. it's tapered, so the farther the plate sits into the dash, the farther you have to screw on the nuts, not sure if that will be a problem or not.

I'll go ahead with this print if I can see some photos to gauge how the radio bezels fit into a 50 year old dash.

[Elarson]

You raise a good point that the dashes might be pretty inconsistent; both from original production tolerances and from shape changes caused by ageing.

The holes in my dash are boogered up by a previous owner to install an aftermarket radio (without a bezel) so I'm no help on that.

If the factory bezel measures 0.625 on the lower radii, I'd go with that.

Eric

[johnta1]

Not sure if this is correct, but just looking at the pic I think the angle needs to be smaller? (which would change the radius?)

[Elarson]

The thing that really complicates this job is that the factory dash isn't a very precise piece. The sides for instance aren't truly a perfect straight line....there is an almost imperceptible curve to them. There's probably some rationale that molding plastic needs some soft corners and draft angles to keep from getting hung up on the mold.

I'm hoping that making the plate 1/16" smaller in both directions makes it less sensitive to the subtle tolerance and shape variations.

Huge thanks to dataway for all of his patience. I'm hoping everybody appreciates the amount of effort he's put into this.

Eric

[unruhjonny]

I would think that the proverbial wild card here is that the dash boards are fibreglass/plastic backed structure covered in vinyl;
This vinyl is prone to shrinking - and likely at openings this might make a bezel seem to not fit.

I would bet that an original radio delete plate follows the dimensions of a radio face plate exactly.

[Trevor78]

I have a spare uncut 78-81 dash. I just measured the radio mounting depressions, 6mm and 13mm deep. I'd imagine the 70-77 would be similar, they just change the layout and size of the face. Or the samples would tell you the same.

[dataway]

Trevor, you would think they would be about the same, but I'm getting measurements more like 4mm from the 70-77 owners.

Eric, what I'm leaning towards right now is going to make one that fits your car and looks good. Since we have no original 70-77 to go by, just a 70-77 radio bezel, we have a certain amount of freedom.
Now I'm wondering of your insert plate is going to fit the new slightly smaller plate.

From Johnta1's picture it appears that the lower corner radius is not matching up on another car ... so that change is making sense, regardless of the radio bezel I traced.

Now ... on to the supports, lots of various dimensions I'm getting for those. I'm going to do away with the center lugs, or make them a tad smaller so I know they fit into any radio hole. What about leaving the supports LONG and the installer trimming them down to position the plate? If you look at the photos from Trevor's post #40 ... the later model OEM plate has supports WAY longer than the measurement I'm getting from Eric, and way longer than the depressions I saw on the 70-77 OEM radio bezel.

The PETG these are made of it pretty tough, not the easiest thing to cut or grind, so I'm not that keen on making them "installer modified"

So right now, two questions for you Eric, are you confident that the 0.16" measurement for the large fins will get the plate where you want it .. WITH the locating lugs INSIDE the radio holes? And ... are both the radio holes depressed the same amount? (to be clear, the "locating lugs" are the quite small fins attached to the "top" of the large fins ... in the OEM application the top of the large fins seated in the depression OUTSIDE the radio hole, and the small locating lugs centered it IN the radio holes.)

Next would be ... is the 1/16" reduction in height and width ... the TOTAL reduction in height and width, or do you mean 1/16" on all edges? (which would mean a 1/8" total reduction in height and width)

This process gives me a bit more sympathy for companies making re-pop parts

[Trevor78]

All good, I had one out for an unrelated reason and thought hmm, I'll measure that just for fun!

[dataway]

Originally Posted by Trevor78

All good, I had one out for an unrelated reason and thought hmm, I'll measure that just for fun!

This process would of course be monumentally easier if I actually owned a Firebird

[Elarson]

Comments added in bold.

Originally Posted by dataway

Trevor, you would think they would be about the same, but I'm getting measurements more like 4mm from the 70-77 owners.

Eric, what I'm leaning towards right now is going to make one that fits your car and looks good. Since we have no original 70-77 to go by, just a 70-77 radio bezel, we have a certain amount of freedom.
Now I'm wondering of your insert plate is going to fit the new slightly smaller plate. the insert plate that you sent is a loose fit height & width in the most recent delete plate, so there's some ability for the delete plate to get smaller without screwing up the fit of the insert..

From Johnta1's picture it appears that the lower corner radius is not matching up on another car ... so that change is making sense, regardless of the radio bezel I traced. I think Johnta's picture is my car picture with his markup?

Now ... on to the supports, lots of various dimensions I'm getting for those. I'm going to do away with the center lugs, or make them a tad smaller so I know they fit into any radio hole. What about leaving the supports LONG and the installer trimming them down to position the plate? If you look at the photos from Trevor's post #40 ... the later model OEM plate has supports WAY longer than the measurement I'm getting from Eric, and way longer than the depressions I saw on the 70-77 OEM radio bezel.

The PETG these are made of it pretty tough, not the easiest thing to cut or grind, so I'm not that keen on making them "installer modified"

So right now, two questions for you Eric, are you confident that the 0.16" measurement for the large fins will get the plate where you want it .. WITH the locating lugs INSIDE the radio holes? And ... are both the radio holes depressed the same amount? (to be clear, the "locating lugs" are the quite small fins attached to the "top" of the large fins ... in the OEM application the top of the large fins seated in the depression OUTSIDE the radio hole, and the small locating lugs centered it IN the radio holes.) Both of my radio holes are depressed the same amount....17-.18" (measurement tolerance) My radio holes are junk and no good for locating. Honestly, for me....I'd like the plate to locate around the dash perimeter and then just have either posts (for the sheet metal nuts) or screw sockets (like you had way back on version 1) at the radio holes that allow for a fastener. In other words...for me...the crossed fins are an unnecessary complication.

Next would be ... is the 1/16" reduction in height and width ... the TOTAL reduction in height and width, or do you mean 1/16" on all edges? (which would mean a 1/8" total reduction in height and width) Yes, I meant total height and total width...not 1/16" on all edges.

This process gives me a bit more sympathy for companies making re-pop parts

[Elarson]

Originally Posted by dataway

This process would of course be monumentally easier if I actually owned a Firebird

Yes, everybody needs one.

Eric

[dataway]

OK then, I will proceed with the new version with the changes.

1/16th smaller in total on height and width

0.75" radius on lower corners

Going to go with 0.16 on the Large post fins, and do away with the smaller locating lugs. I think the post needs the support the fins provide to keep from snapping off. I suspect you are not the only one with messed up radio holes, so it makes sense to keep those attaching points as simple as possible.

I'm going to assume that most people downloading the print files will be reasonably familiar with printing, and how to alter the files to their liking as far as the attachment method. The critical point will be how it looks, so the work on the plate shape and contours is worth it.

Will print something out today and should have it in the mail tomorrow ... I do have a left over insert plate here I can check for fit.

Revision 3 coming up

[dataway]

The new print came out nice. But, going to have to print a new insert also. The 1/16" change isn't a problem, but the change in lower corner radius makes the fit there less than great.
But the inserts are very easy to print. I'll throw one in the box with the new plate.

Eric, save the last plate I sent, and the insert ... maybe send them to someone else what needs a delete plate ... might work for them, might not ... I mean better than nothing if someone needs one.

[dataway]

New insert fits nice. I'll get them in the mail Tuesday.

[242177P]

Originally Posted by dataway

I could rotate the standoffs 90 degrees so the centering lugs would miss the antenna adjustment ...

You and I both know you meant 45°, but when you stop and
think about it... I suspect you'll enjoy this mental image.

[dataway]

Think about it a bit longer .... I'll give you a minute

There are only two centering lugs ... four fins, two centering lugs (little projections on top of the fins) which were oriented vertically ... so turning the support 90 degrees would orient them horizontally ... so they would miss the trimmer holes The large fins seat against the metal face of the dash, the lugs were supposed to go inside the radio hole and orient it top to bottom ... but of course the trimmer hole being aligned vertically messes that up. However .... that exactly how the OEM 78-81 plates are aligned.

Several pages ago I should have posted a diagram with all the features labeled so we'd all be on the same page with terminology ... probably would have sped this whole process up quite a bit .... I guess that's why people use parts diagrams

Eric, latest version going out today.

[cnc]

Watching waiting with anticipation...

[Held for Ransom]

I didn't think it would take this long.

Dimension of the radio pocket depth is 0.17". Add to that the vinyl thickness of approx. 0.035" and glue thickness and any wrinkles. I would think the 0.30" height would be fine, 0.25" min. Radio hole opening is approx. 0.48", 0.45" width should be suffice. And, turning the stands to x's, instead of +'s would work too, maybe better.

[242177P]

Originally Posted by dataway

Think about it a bit longer .... I'll give you a minute

Ugh. Assumed (I know, I know) the standoffs were symmetrical.
Figured the fins were centering the plate. In my defense, it was
almost 2AM, and I can be an idiot with the best of them when
tired. Yeah, yeah, that's it.