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Z'd, ZEED FRAMES SIMPLIFIED TUTORIAL


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I've seen a lot of guys zee frames...some do more work than is necessary, some struggle, some do it un-necessarily for the look they're after. And usually, IMHO, it's just not necessary to Z the front of a frame. Between dropped axles and the old suicide type spring perch, you can get a LOT of front end drop. However, sometimes there's a good reason to Z the front rails. Here's how to do both ends quickly and painlessly. With slight modifications, this method will work for virtually any ladder-style frame. If you're careful the frame ends up SQUARE, and the wheelbase doesn't change.

This chopped '32 gluebomb body on stock Revell rails is going to need the rear Z'd, and we're going to do the front at the same time. The procedure is basically the same. It's usually a good idea to plan where your Z will start, and this one in front is going to start exactly at the firewall. In a real car, this is really the best place. It's easiest to use this particular technique if you make the Z where the top and bottom of the rails are parallel.

BIG NOTE: BECAUSE YOU WILL CUT ON THE DIAGONAL LINES (those are the slanty ones) THE LENGTH OF THE CHASSIS WILL NOT CHANGE. Read through the whole procedure and try to UNDERSTAND WHAT'S HAPPENING HERE.

The VERTICAL LINES (the uppy-downy ones) ARE FOR ALIGNMENT OF the cut ends. If the chassis was cut on the vertical lines, the length of it would have to be shorter when you overlapped the cut ends, but CUTTING ON THE DIAGONAL eliminates the chassis shortening that would otherwise result.

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The cuts for the Zeees will be the DIAGONAL lines. The vertical lines are for reference, and show where the Z starts relative to the body. I use a very fine Sharpie for the lines.

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Transfer your cut and reference lines across both the top and bottom of the chassis. Make SURE everything is square at this point. If your lines get nasty, you can clean them off with isopropyl alcohol and start over.

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At the rear, extend your cut lines up the floor sides and across the top. Make SURE your cut and reference lines are SQUARE and ACCURATE. Cut lines are the DIAGONALS.

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Make your cuts with a razor saw. Cut across the top of the rear floor first, keeping the saw square across the floor and not going down into the rails. When you're just barely through the floor, CAREFULLY make your DIAGONAL cuts. Take a file and TAPER the sides of the rear floor towards the rear of the car, as shown, for clearance. Cut the front rails the same way, leaving the crossmember in place to keep everything aligned.

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Remember those reference lines? Glue your cut sections DIRECTLY ABOVE where they used to be. Make sure your diagonal lines are PARALLEL as you glue everything back together. Check everything for squareness from the top. You'll see that because we cut the rails on the diagonal and placed the cut ends directly above their original locations, the chassis is exactly the same length as it was, so the wheelbase ( distance between axle center-lines ) is the same. This technique gives you a QUICK and ACCURATE Z that's the depth of the frame at the point you cut it, and it avoids all the monkey-motion of making vertical pieces, etc, and the headaches of keeping all those pieces aligned.

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Here's the chopped '32 shell on the newly Zeeed rails. Front Z starts nicely at the firewall, keeps the kinks out from under the engine, and out of the interior. It also works well to start the front Z inside the car behind the firewall, which gives straight rails AHEAD of the firewall. You will have to modify the firewall and the floors more with that approach. The rear has plenty Z for a fair amount of drop, about 6+ scale inches. Rear rails can also be Ceeed (cutting a C-shaped notch in the bottom of the frame rail for a little more clearance for the axle) over the rear axle if a little more lowering is wanted. Combine the front Z with a dropped axle or a suicide mount, and you can get the rails on the ground under the body shell. If you want even more drop in the rear, you'll have to use vertical spacer pieces between the cut rail ends and the original rails. Or, with a little judicious adjusting of the angles at the glue joints, you can get a little more drop without screwing up the overall length and wheelbase.

How you reinforce the glue-joints is up to you. My method is to thin the rails at the joint by about .020" on both sides, and add two plies of fine RC model airplane fiberglass and slow-cure eopxy. When cured, I file the sides of the frame to the original width. No goofy looking lumps of styrene, no breaking during subsequent handling.

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You can get pretty radical with this simple Z . This is that same frame with a dropped axle under the stock front cross-member, but a suicide mount would put the rails on the deck. The channeled '32 tub is the old Switchers version.

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Edited by Ace-Garageguy
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That's exactly how I did the frame on my F-1 pickup. I did do mine different at the rear since I was making the frame and bed shorter and just made a vertical cut. This method makes Z 'ing the frame so simple. The only problem with a Z'd frame is that it almost always causes clearance problems with the floor pans. :(

Yup, and zeeing a frame always creates floor clearance issues on full-scale cars too. What we do is the same as the big ones, only smaller. B)

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Thanx for the clear and concise write up. Lining up the the cut with the vertical from the base of the diagonal eliminates a lot of problems with fitting the chassis parts and the body once the drop is completed. Thanks for stressing that. I agree with your comment about front Z's. I tend to avoid them as unecessary in most cases, but I also think that they have a tendancy to be somewhat unsightly, as well as raising the bell housing and transmission deeply into the passenger area. If I do them at all I like to tuck them behind the firewall, but there's a big negative, which is that it eats up huge amounts of interior space. An old technique sometimes seen that was surprsingly common in the early days, but I think is even more unsightly, is to Z the front up behind the front crossmember.

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  • 3 weeks later...
  • 2 weeks later...

Man i have been looking forever to find this info.....THANK YOU I am building the PICKLE 1932 sedan in under construction. It took forever to do my rod and this is much better. Unfortunatly the pickle has to be redone,(due to some father and son wrestling misshap) and i will be doing the frame this way.......FISHDATTY.. Also you should do a youtube video on this .....

Edited by fishdatty
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On Revell's '32 chassis you can achieve a not insignificant amount of drop by just cutting down Bill's front vertical line almost all the way with a razor saw. Leave about 1.5mm (OK, 1/16") uncut on both sides.

The razor saw will have removed enough material that you will be able to carefully bend the rails upwards closing the gap. It will however spring back.

Put a block under each end of the chassis and stand something on the middle of the chassis that is just heavy enough to close the gap. I use a tin of paint.

Now drip a small amount of styrene cement onto the top of each cut and leave it to set.

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On Revell's '32 chassis you can achieve a not insignificant amount of drop by just cutting down Bill's front vertical line almost all the way with a razor saw. Leave about 1.5mm (OK, 1/16") uncut on both sides.

The razor saw will have removed enough material that you will be able to carefully bend the rails upwards closing the gap. It will however spring back.

Put a block under each end of the chassis and stand something on the middle of the chassis that is just heavy enough to close the gap. I use a tin of paint.

Now drip a small amount of styrene cement onto the top of each cut and leave it to set.

Yup, that's a good trick and it can give a nice line to the front rails and enhance a car's rake without too much work. Good post, Zen.

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On Revell's '32 chassis you can achieve a not insignificant amount of drop by just cutting down Bill's front vertical line almost all the way with a razor saw. Leave about 1.5mm (OK, 1/16") uncut on both sides.

The razor saw will have removed enough material that you will be able to carefully bend the rails upwards closing the gap. It will however spring back.

Put a block under each end of the chassis and stand something on the middle of the chassis that is just heavy enough to close the gap. I use a tin of paint.

Now drip a small amount of styrene cement onto the top of each cut and leave it to set.

Yup, that's a good trick and it can give a nice line to the front rails and enhance a car's rake without too much work. Good post, Zen.

That's what I just did on a project I have going and it makes a really sweet curve.

DSCF1643-web.jpg

DSCF1640-web.jpg

Edited by Bernard Kron
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"without too much work"

That's the clincher! :)

That's what I just did on a project I have going and it makes a really sweet curve.

DSCF1643-web.jpg

That looks great B. The way the curve of the bottom of the body flows into the curve of the frame is spot on.

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Just a simple question those of you that mod the frame .Do you leave the frame in its shorten state or do you add styrene to achive the original length?

If you read the text and think about what's being done, you'll see the FRAME REMAINS THE SAME LENGTH if you do the procedure above.

That's one of the main reasons to do it this way...to avoid all the Micky Mouse un-necessary lengthening that's so often a part of frame Zees.

Edited by Ace-Garageguy
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  • 1 month later...

Just a simple question those of you that mod the frame .Do you leave the frame in its shorten state or do you add styrene to achive the original length?

Easiest way to do that is to use a second frame, which will allow you to make the kicked up portion at the rear longer to compensate for the shortening effect that would otherwise have to happen.

Art

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Easiest way to do that is to use a second frame, which will allow you to make the kicked up portion at the rear longer to compensate for the shortening effect that would otherwise have to happen.

Art

NO NO NO. I do NOT understand why the SIMPLE GEOMETRY of this is so hard to understand.

LOOK at the 45 DEGREE cuts in the 6TH PHOTO, and how the cut ends relate to each other when reassembled. THESE CUTS ALLOW THE FRAME TO REMAIN THE SAME LENGTH.

If the cuts were made at 90 DEGREES, and the ends overlapped, there WOULD be shortening, BUT NOT AS SHOWN !!!!!

WITH 45 DEGREE cuts THERE IS NO SHORTENING. THIS IS SIMPLE HIGH SCHOOL GEOMETRY., common sense and OBSERVATION.

WHY must you CONTRADICT CORRECT INFORMATION ??

DO the mod AS SHOWN and MEASURE IT !!!!! I have done this MULTIPLE times MYSELF, on REAL chassis AND MODELS and MEASURED IT, it's accepted as correct in the history of hot-rodding and cited in MANY OLD PERIOD ARTICLES. IT WORKS AS STATED.

There is NO DAMM SHORTENING !!!!

Edited by Ace-Garageguy
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I found your tutorial on another site a long time ago and used it on my 32 5 window ford and have to say it worked great. Everything lined up and was very easy to do. Thanks for posting it again Bill, great tutorial.

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not understanding. how would the shortening (with the exception of the saw kerf - which is easily remedied) take place?

I really hope there's no scale arithmetic involved!

Yes, you don't even lose the width of the saw kerf if you very slightly adjust the final position of the cut parts when you glue them back together. No scale arithmetic required. :)

I suggest putting reference marks close to the ends of the rails BEFORE cutting, measure between them, and make sure you have exactly the same measurement when you glue everything back together. B)

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The best way would be to place a small mark on the top of one rail (where it looks like a good place to do the cut), measure the distance of this mark from a fixed point of the rail (like where it intersects a crossmember) with a dial-caliper, and transfer this measurement to the other side of the frame, where you'd make a corresponding mark.

A line drawn between these two marks will be perpendicular to the centerline of the chassis. If you're careful, you should be able to get within a few one-thousandths of an inch.

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