Barn Door for JK factory hardtops

[Septu]

Can you elaborate on how you think the integrated roof rack mounts "partially resolve the issue of a roof rack"? I've had the same feature on the LJ Safari Cab since the beginning, and I've carted lots of stuff up there, including a roof-top tent, and I've never felt like there was some issue it didn't resolve. If I know more about what the issue is that you see in the design maybe I can alter the design to eliminate whatever the issue is.

Sure thing. I like it when people ask for my opinions - they usually don't want them LOL!

First off, other than perhaps the MBRP rack (which would still take some work if one wanted the front addition, and to deal with the side windows), due to the extra height of the roof, the design likely eliminates almost every rack that's been made for a stock JK. Sure with some work and customization I'm sure someone could get one to work... but unless they can do it themselves, it likely wouldn't be cheap.

As for how your design only partially solves that issue. While it works for the style of RTT you have on it (basically the same as my old Tepui), I'm highly skeptical that it would work with my James Baroud clam shell type RTT due to the placement/limitation of the first load bar. Good news is that most of the weight (on mine - JB Escape) is in the middle and at the back, so maybe it might work... but I still think it would look odd with 2' of overhang (from the front loadbar) on the front. Additionally - and while I can't be 100% certain due to not having seen your LJ rack, but if it's anything like the one AEV came out with, it's unlikely that it's setup to have the hard top on/off multiple times like a Gobi/MBRP/etc would allow for. Lastly... due to the curve of the roof, having a full length rack/basket would likely require a new front load bar (say something like a KMA custom light bar setup). And then would still look somewhat silly and at odds with the roof design itself.

So yeah... for me it would partially resolve the roof rack issue. It would likely allow me to pack lumbar and my kayak without major issues (especially the kayak). It would allow me to put a bike, awning, or one of those enclosed cargo carriers up there, or a small basket like what you've depicted. But I'd be pretty hesitant about getting something like this with the idea of mounting my JB RTT to it. Or if I was someone that swapped my HT on/off multiple times during the summer, or felt I might want/need a full sized basket.

 

[jscherb]

Sure thing. I like it when people ask for my opinions - they usually don't want them LOL! ....

Thanks for taking the time to write such a detailed response. Good stuff for me to keep in mind!
jeff

 

[jscherb]

...I'm highly skeptical that it would work with my James Baroud clam shell type RTT due to the placement/limitation of the first load bar. Good news is that most of the weight (on mine - JB Escape) is in the middle and at the back, so maybe it might work... but I still think it would look odd with 2' of overhang (from the front loadbar) on the front...

Here's what a Baroud Discovery Space tent would look like on the JK Safari Cab; in this drawing the rack is a factory XJ Cherokee rack. You may have a different model Baroud tent, but it looks like they all share the same hard shells, so yours is probably the same length. It doesn't look like there's an unreasonable overhang on either end.

 

[jscherb]

The only issue with that is you need the height at the feet like you get on the J30...

So as I was researching the Baroud hard shell roof-top tents for the last post, I learned that they're 79" long; the JK roof is about 10" longer. So somehow people seem to be able to sleep in the Baroud Discovery, so they'd have even more foot room in a tilt-up based on the Safari Cab roof panel (shown tilted up in red dashes):

 

[Septu]

So as I was researching the Baroud hard shell roof-top tents for the last post, I learned that they're 79" long; the JK roof is about 10" longer. So somehow people seem to be able to sleep in the Baroud Discovery, so they'd have even more foot room in a tilt-up based on the Safari Cab roof panel (shown tilted up in red dashes):

They are about that length - and it's (mine) still somewhat short - and I'm 5-9. Another 2-3 inches would make a big difference. The main reason why it works at that length is that the front part of the tent also lifts up. Fortunately I usually sleep with my feet (size 10-11) pointed to the side... otherwise my toes frequently hit the top. Not always... but they do just enough to notice the length.

 

[jscherb]

I've been working on a mold for the JK Safari Cab roof, and yesterday I molded a roof panel. Here it is just out of the mold - I haven't trimmed it or washed the mold release off yet.

If something doesn't look quite right to you about the roof panel in the photo above, you're right... it's a 1/10 scale model .

For most of my large design projects I build scale models to help visualize the design in 3d and to help me work through design and construction details. For example, when I was in the design phase of my fiberglass military trailer kit project, I made a 1/4 scale model so I could test exactly the details of bolting the tub parts together into the complete tub.

Here are a few photos of that model project:

Compared to the final full-size version:

I worked in 1/4 scale for the military trailer project model because I needed to actually bolt the parts together just like the full scale would bolt together.

For the JK Safari Cab roof, I'm working in 1/10 scale because there's a 1/10 scale JKU model on the market - it's made by Axial, and has a vacuum-formed body that looks like it's very accurately scaled. Since I've designed the Safari Cab side panels to be compatible with the factory hardtop size and shape, the roof panel I molded will fit correctly on an Axial hardtop.

Some photos of the Axial hardtop and an Axial JKU:

I'll get the new roof trimmed and fit to the Axial hardtop shortly, then we can see what the full scale JKU Safari Cab will look like.

 

[jscherb]

A few shots of the 1/10 scale model roof. I haven't finished the trimming yet, so it's not fitting perfectly in these photos. There are a few flaws in this roof due to a resin issue, so rather than spend any more time trimming and fitting it, I'll mold another roof today and I'll spend the time fitting that one.

Mockups of the Alpine windows have been glued on to one side...

 

[SLOfizz]

Doing a mechanism like the J30 is a fallback position for this one, but I think it's worth prototyping it as I've shown it to see how the room inside really works out. Both the J30 and the AEV unit have something taking up room that this design doesn't - the roof/false floor. My plan is to mount the sleeping platforms directly on the sport bars, which saves quite a bit of space (and weight) over that those others have. That additional space should also be enough for the mattress/tent fabric as you mentioned.

There is not that much space wasted by the J30. The bottom of the floor/roof is right above the sound bar. You need a floor to sleep on, so you can't just remove it. It is a composite panel to save weight, a little over an inch. Then there is the mattress for 2+ inches. The top/roof takes up over an inch. Needs to be rigid, so it's thick. Has a false ceiling to hide fasteners and light wiring. The remaining space is used for fabric. That's how you get to 6 inches.

You could ditch the ceiling/lighting to get 1/2 inch. Use thinner tent fabric, but reduce durability. The floor panel could be reduced by recessing it and eliminating access panels or you can reduce the mattress. All those reductions make the product less desirable.

I also know how many J30s were made as of a year ago as they are all numbered. It is not a lot. Not a big enough market for a competitor.

 

[jscherb]

There is not that much space wasted by the J30. The bottom of the floor/roof is right above the sound bar. You need a floor to sleep on, so you can't just remove it. It is a composite panel to save weight, a little over an inch. Then there is the mattress for 2+ inches. The top/roof takes up over an inch. Needs to be rigid, so it's thick. Has a false ceiling to hide fasteners and light wiring. The remaining space is used for fabric. That's how you get to 6 inches.

You could ditch the ceiling/lighting to get 1/2 inch. Use thinner tent fabric, but reduce durability. The floor panel could be reduced by recessing it and eliminating access panels or you can reduce the mattress. All those reductions make the product less desirable.

Thanks for the info, all very helpful to know.

I also know how many J30s were made as of a year ago as they are all numbered. It is not a lot. Not a big enough market for a competitor.

I'm sure that's true. I'm not doing this project because I want to compete with Ursa Minor, or because I have any personal plans to make the JK Safari Cab into a commercial product - I'm doing it because I enjoy design and construction challenges like this. I'm making the JK Safari Cab for myself and maybe I'll make a second one for someone, and then I'll move on to another design project. And I'll keep the molds in case some company contacts me and wants to make a production product out of it, or in case I find a reason to make another one or two.

I really appreciate input like yours, any input or criticism I get helps me make the design the best it can be. Thanks again.

 

[GFA]

When you move on to that next project can it be a hardtop that is removable by one person? Like a 5 piece top or something, purdy please??

 

[jscherb]

When you move on to that next project can it be a hardtop that is removable by one person? Like a 5 piece top or something, purdy please??

I remove the Safari Cab on my LJ by myself, and this one will be the same. The roof panel is pretty large so it's awkward, but I do it solo and the side and rear panels are very easy.

 

[SLOfizz]

Thanks for the info, all very helpful to know.


I'm sure that's true. I'm not doing this project because I want to compete with Ursa Minor, or because I have any personal plans to make the JK Safari Cab into a commercial product - I'm doing it because I enjoy design and construction challenges like this. I'm making the JK Safari Cab for myself and maybe I'll make a second one for someone, and then I'll move on to another design project. And I'll keep the molds in case some company contacts me and wants to make a production product out of it, or in case I find a reason to make another one or two.

I really appreciate input like yours, any input or criticism I get helps me make the design the best it can be. Thanks again.

Glad to help. I know you're not making this into a production version. I do hope for your success on making a camper top and maintaining the sloped front. I debated getting the top for months because it literally destroys the looks of the jeep, but the use factor eventually won. I think you could get some more room in the front by changing the material used for the cab roof/floor in the back vs. the front. The J30 uses the same thick composite material the entire length. I think the panel over the driver could be way thinner. This would cause a step in the sleeping platform. If you detailed it correctly so there was not a large step and tapered the foam mattress pad, you could gain a lot of room in the front. Ursa Minor went for an easier to build, fully functional solution on that part to make a viable product, but since this is a one-off, you could put in the extra time. I would use the lift mechanism that they use to get the height at the front. It is very simple, allows an easy mounting point for shocks to assist in lifting and you get the room/window at your feet. I use that window every time I sleep up there. Opening it gets you the cross ventilation you need and I leave it open when I put the top down as the tent acts like a bellow when you put it down. If you don't give the air a place to escape, it makes closing it a pain. You also get more head room as you are limited on your roof angle. If you just hinge it like you drew, you need a sleep angle to get the head height which makes the tent more of an A frame. You loose a lot of space. The way theirs works is super slick, gets you an almost vertical wall at your head (less waterproofing concern), room at your feet. You can move around and change your cloths and not feel like you are in a tiny space. There is enough room for single person to lounge up there and feel like a king, which makes me not have buyers remorse every time I am up there. I have spent hours up there awake, relaxing. I would never do that in the roof top tent you modeled.

I have been in the rooftop model you are using in your design pictures. Of all of them, that design is the most constrictive in terms of space. I am 6-2 and can't fit in it with out hitting head/foot and I am use to backpacking tents. I would never buy that model. I would have to get the one that lifts strait up, but the head height sucks in that one. There really isn't a hard shell rooftop tent on the market that gets you the space in the J30. Only the 180 degree flipping models do and those will eventually wear out, are hit hard in wind/rain/snow. I can patch the J30 back together for years if it gets damaged and not worry about it. If the flip type rooftop tent wears out, you can remove it for repairs/replacement. Not as easy if its your car's roof.

If ou are serious about making the tent version, let me know as I got a few ideas about improvements.

 

[jscherb]

Glad to help. I know you're not making this into a production version. I do hope for your success on making a camper top and maintaining the sloped front. I debated getting the top for months because it literally destroys the looks of the jeep, but the use factor eventually won. I think you could get some more room in the front by changing the material used for the cab roof/floor in the back vs. the front. The J30 uses the same thick composite material the entire length. I think the panel over the driver could be way thinner. This would cause a step in the sleeping platform. If you detailed it correctly so there was not a large step and tapered the foam mattress pad, you could gain a lot of room in the front. Ursa Minor went for an easier to build, fully functional solution on that part to make a viable product, but since this is a one-off, you could put in the extra time. I would use the lift mechanism that they use to get the height at the front. It is very simple, allows an easy mounting point for shocks to assist in lifting and you get the room/window at your feet. I use that window every time I sleep up there. Opening it gets you the cross ventilation you need and I leave it open when I put the top down as the tent acts like a bellow when you put it down. If you don't give the air a place to escape, it makes closing it a pain. You also get more head room as you are limited on your roof angle. If you just hinge it like you drew, you need a sleep angle to get the head height which makes the tent more of an A frame. You loose a lot of space. The way theirs works is super slick, gets you an almost vertical wall at your head (less waterproofing concern), room at your feet. You can move around and change your cloths and not feel like you are in a tiny space. There is enough room for single person to lounge up there and feel like a king, which makes me not have buyers remorse every time I am up there. I have spent hours up there awake, relaxing. I would never do that in the roof top tent you modeled.

I have been in the rooftop model you are using in your design pictures. Of all of them, that design is the most constrictive in terms of space. I am 6-2 and can't fit in it with out hitting head/foot and I am use to backpacking tents. I would never buy that model. I would have to get the one that lifts strait up, but the head height sucks in that one. There really isn't a hard shell rooftop tent on the market that gets you the space in the J30. Only the 180 degree flipping models do and those will eventually wear out, are hit hard in wind/rain/snow. I can patch the J30 back together for years if it gets damaged and not worry about it. If the flip type rooftop tent wears out, you can remove it for repairs/replacement. Not as easy if its your car's roof.

If you are serious about making the tent version, let me know as I got a few ideas about improvements.

Thanks again for the input, it's very helpful! I really appreciate the time you must have spent writing it as well.

I haven't yet decided which other variants of the JK Safari Cab I'll build prototypes of - when I did the LJ Safari Cab I also did a half cab and a camper trailer out of the same molds (unfinished prototypes pictured below). So I might decide to do a trailer camper variant, or a half cab, or maybe this time I'll do the tilt-up camper we've been discussing.

Having recently built the tilt-up camper top for the Jeep-tub trailer, I'm confident I could do a successful tilt-up hardtop camper, it would differ only in detail from what I've already built.

 

[jscherb]

Popped the second roof out of the mold this morning. Did some quick trimming and tried some windows and sunroofs on. Next I'll paint the roof and the hardtop dark gray and put some window trim in so they model looks a bit more realistic.

 

[jscherb]

The painted 1:10 scale model JK Safari Cab.

With no Alpine windows in the roof:

With two Alpine windows on each side of the roof:

Alpine windows can be installed one per side, on the left is one over the passenger row of seats, on the right is one over the cargo area:

With sunroof(s):