my 1932 datsun replica build

This is the Kwik Top Universal Roadster Convertible Top Iron Kit from Speedway Motors I am trying to modify to use on a phaeton (aka "touring") style car

Each side of the kit is made of five pieces of 3/16" thick flat rod that is 3/4" wide. 

Four pieces are straight, one is bent.

They are drilled with 1/4" holes, and held together with 1/4 bolts and nylocks 

This surprises me, but it looks like the large bolts that are supposed to attach the frame sides to the automobile body's mounting tabs are 10 mm Size

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The top bows are made of three pieces of half inch diameter tube; a centerpiece of 1/2" straight tube that is 39.5" wide, and two curved side pieces that are splined to fit into the top tube. Assembled, the 3-part top bow is just over 58 in wide.

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The quick top kit comes with two top bows; a larger one that is around 48 in long and  11 in high, and a smaller one that is 55 in wide and 8 in high 

Here's a photo showing the top frame of a Packard phaeton. I took this photo at the 2024 Lake Mirror Auto Show

​​​​​​At the time, I thought that the scissoring top iron stuff was probably Packard-specific. As of this weekend, I know that is not the case; the Ford apparently did a similar thing.  I would not be surprised if other manufacturers also used the scissoring mechanism; this may have been standard top construction back in the 1910s and 1920s when  phaetons were the most popular models of automobile. (Hagerty link)

BTW, I *now* know that there are top iron kits for Ford phaetons.  

If I had known back at Thanksgiving that such kits exist, I could have gotten one and then modified it to fit my datsun-ish rat rod.  Instead, I am now trying to make a roadster top into something not-a-roadster.  It is frustrating, but I still think it is possible.  Here is my attempt to make a wooden mock up of the scissoring portion of a top.

that's eight pieces, each 12 inches long, cut from some yard sticks. in the closed position, the scissoring piece is roughly 4.5" x  12".  In the extended position,  this is 42" long, which is more than the distance from the windshield to the roll bar.  There's also a 15" piece that attatches to the winshield

Translation:  this is probably long enough to make it work.  It will require at least 16 feet of flat rod....probably a few more than that so I  weld a few pieces together to create offets that clear the  bolt/screw heads. By the end of this week, I might be able to make a full size 2D mockup of one side of the top.

Maybe sell it /see if you can get it refunded as long as you haven't modified it get, and get the ford phaethon one to make fit?

Piguin said:

Maybe sell it /see if you can get it refunded as long as you haven't modified it get, and get the ford phaethon one to make fit?

That would be smarter, but I've already scratched some of the pieces. Besides I think I can pull this off

this is how the stock roadster top iron frame folds up and extends.  I tried to upload an animated GIF, but the animation was taken out. I will put a link here to the same video as an Instagram post.

The wood is to represent the height of a top bow... I'm still looking at options for height, though

Today I tried making a three-part top bow - mimicking the ones from the kit - out of conduit. Making splines to join the three pieces was.... Not a success.  Will try again 

I'm I'm not done messing around with wooden mock-ups, but I'm pretty sure that the frame will need to mount to the body between 14 and 16 in back of the roll bar. The total height of the back bow will probably need to be about 35 in. From the mount on the body 

Unrelated: the dog was begging for a car ride, so I took her puttering around the neighborhood in the loud car 

Ok, so now I know I can replicate the top bows of the kit using conduit....even the male ends used to connect the top tube with the curved side pieces.  I made the male bit by removing a strip of conduit, using vice grips to gently persuade the conduit to become narrower, welding it back together, and sliding it into the curved side piece of conduit.

I just spent a couple hours playing with my slow HF  band saw and some tubing.  This was an attempt to cut pieces for a pair of brackets to mount the convertible top to the car body

The pieces cut from that tube ready to turn into a bracket 

The corners still need to be radiused, and I need to drill the mounting holes for the bolts that will attach it to the body, but here is what one of those brackets to mount the top will look like 

Didn't do any building today, and won't start again until a few days after Christmas.  I hope you folks all have a Merry Christmas or, if that's not your thing, that the next few days are peaceful and happy.

May the next year let you get a few miles closer to your goals.

on 12/12. I tried to use conduit to mimic top bow parts of speedway's top iron kit. As part of that effort,  I narrowed a piece of conduit to make the male ends that stick out of the curved side pieces of the top bow.  Today, I did the same thing so I will have the ability to construct a second top bow.

This was made using the same technique as before; i.e removing a strip, bringing the edges together by squeezing with vice grips, welding it back shut into a continuous tube.  The little "collar visible in the third picture is a piece  1/2 inch piece of the original tubing.  I am using this piece as a test to ensure my narrowed tube is reduced enough to fit inside the original sized tubing.  Pieces of the original sized conduit will be bent to form parts of the top bow

Here's the first attempt at a DIY top bow/top iron, in both a raised and lowered tentative position. 

In this test fitting, the top bow is resting against the roll bar. In actual deployment, it would probably be positioned at about the same height, but rearward three or four inches, with the fabric going over the bow and then rising just slightly, maybe half an inch, as it goes over the roll bar in the front 

Here are the two factory bows and my attempt at a taller homemade bow.  

I am pretty sure I will need to make an even taller one.  It may be possible to use the shorter of the two commercial kit bows without modification.

Looking good so far.

The  first two photos makes it look like the bow is 'sitting' at different spots, fore and aft of the roll bar back brace. Just checking if it is indeed the case or a result of the different angles between the photos.

In reply to Piguin :

Yes, you are seeing correctly.  I still haven't finished figuring out the length needed for the curved side pieces. This was mostly a check for width.

The mounting bracket that ties the top to the body will probably be 14 in or 16 in distance behind the vertical sides of the roll bar.

Here's a side view of what the top frame might eventually look like, drawn onto a photo of my car*  The thin blue ink lines are pieces from the original kit.  The thick blue highlighter lines would be built from conduit.  The Packard-style stuff between the front and back would be 3/16 flat rod. (I expect that to be strong enough because a lot of the speedway kit is made of 3/16 flat rod.) Scroll up to 12/15 o see the Packard convertible top, and my wooden mock up of a similar scissoring mechanism.

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* - the photo is flipped ro match the orientation of the photos above.  In real life,  my exhaust on the inline six is on the driver's side

Today has been one of those good news/bad news situations.

The good:  "1/2 inch" EMT conduit - called this because it is designed to hold wiring up to 1/2 inch cross section - actually has a 5/8 inch interior diameter, which means that it can take these 5/8 inch fittings for Bimini tops. 

 This has the potential to be a good thing.  I am definitely going to try using a pair of these 5/8 ends with bimini sliding jaw clamps for the hinges on the top irons/bows 

the bad news:  3/16 inch flat rod I need for the Packard-style scissoring parts of the top may be difficult to find at a reasonable price.  the big box stores are too high:  Lowe's is charging ~ $10 for 3 ft.  At Home Depot, the same 3 ft is more than $14.   Mine and Mill advertises the far more reasonable price of $15.69 for 20 feet, but my local store says they haven't had any 3/16 - in any(!!!) width - for many months

And.... the bad?

Piguin said:

And.... the bad?

sorry.  was editing.  My local Mine and Mill hasn't had any 3/16 flat rod  - of ANY width - in over 4 months.  I'm about to add details above.

That does suck. Since we are on the scissoring subject, have you given any thought to using less but longer parts?

I am not as much worried about the complexity, or the extra work required with more parts (since I am safely behind my keyboard and not having to actually do the work), but more about ease of use and simplicity. More moving parts, harder adjustment, more things to 'catch' and impair fluid function.

In reply to Piguin :

Yes, I have thought about it.  I've been thinking " complicated " just because I wasn't sure if I could pull it off with "simple."

The top on the original car was certainly framed with fewer parts. 

It was a kei car, though, with a 75.5 inch wheelbase.  My lookalike is much larger; the engine bay is 42 in long.  More importantly, the distance from the dash to the roll bar is 44 in.  That's a lot of distance to cover

JoeyM said:

In reply to Piguin :

Yes, I have thought about it.  I've been thinking " complicated " just because I wasn't sure if I could pull it off with "simple."  The top on the original car was certainly framed with fewer parts. 

 

I should have said the picture above is a screenshot from this video.  Here is the same screenshot, but lightened to show top frame details

Notice the two spots indicated by arrows.  The back arrow appears to point to a metal bracket where a wooden top bow attached to the frame.  The front arrow points to a spot on photo showing a change in color on the frame.  I can't see the connecting bolt, but I suspect that might be a place where there's a hinge between two pieces of flat rod.

No car building today, but I did find photos that might be useful in planning a convertible top

Good photo of a 1933 type 12, the car in the Zama museum that mine is an attempt to mimic

Type 12 with top down

Type 12 with top up (really useful pic. Shows that the center portion of the top is sewn from three main panels of fabric, and east side from two large triangle-ish pieces and one long horizontal rectangle below that)

1929 Austin Seven (the other car the Datsun type 11 & type 12 most resemble is the 1930 Austin)

The link for the first picture is unfortunately broken.

Indeed very handy links from what I can see.

Piguin said:

The link for the first picture is unfortunately broken.

Thanks for the heads up. The link is fixed