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OT: Kayak roof rack design

martin_05

Hot Rolled
Joined
Mar 11, 2009
Location
Valencia, CA, USA
Please delete without mercy if it doesn't belong here on anywhere else on this site.

I need a couple sets of these:


Well, nobody has any and nobody knows when they'll receive a new batch. Not even the competitor's equivalent system.

So, I said, I have a nice assortment of manufacturing equipment. I should be able to make something like this.

Which led to the question of: How to design it.

I can probably copy most of it from assorted videos and have my sheet-metal guys bend-up the channel, etc. On the other hand, I have a pretty good supply of 8020 profiles on hand (mostly 1.5 x 1.5). Maybe I can do something with that.

I haven't designed anything yet and I have zero intention on attempting to manufacture something like this for wide distribution. I just need two rigs to transport two kayaks.

I thought the brain-trust present at P.M. might have some suggestions on a simple design that would accomplish the job and is easy to fabricate.

To clarify, our local lake has this requirement to hand-inspect every single boat due to this Quagga mussel threat.

Quagga and Zebra Mussels

This means that if you don't have something like this they make you unstrap the kayaks, bring them down to the ground and then you have to put them back up and strap them to drive to the ramp...rinse and repeat to get on the water. If it were not for that I would have no issues at all just strapping the kayaks to the pipes on the roof. I need something that allows me to bring the kayaks down in front of the inspectors in seconds so we can get on with our day with the least possible level of aggravation.
 
The key feature is how it telescopes out from the linear guide which holds it until the very limit of extension, where it can pivot down and it evidently does this without excessive torque on the linear guide right before it is free to pivot. I can think of ways to do this with 8020 and linear guides of the sort 8020 makes, but one would ideally want to CAD it up carefully and have a good look.
 
Looks kinda wide for 2 boats on one car. This seems pretty complicated and guaranteed super noisy in the wind with or without a boat. Would you take this contraption off when you're not boating?

Ropes would be your friend here unless you have bad shoulders or back. Flat on the bars upside down. Saddles and minimal tie down might help secure the boat to get from inspection to ramp.
 
A couple of really good designs! Wish I had something like that when hauling sailboards on top of my Suburban.

Something else you might consider is buying a used JetSki trailer and modifying it to carry the kayaks. Yes, that means that you would have to store it somewhere, but it also means that you wouldn't have to haul the rack everywhere you went. And you wouldn't have the hassle of putting it on and taking it off.
 
The key feature is how it telescopes out from the linear guide which holds it until the very limit of extension, where it can pivot down and it evidently does this without excessive torque on the linear guide right before it is free to pivot. I can think of ways to do this with 8020 and linear guides of the sort 8020 makes, but one would ideally want to CAD it up carefully and have a good look.

Yeah, I am going to sketch a few ideas and get on Solidworks over the weekend. Thanks.
 
Looks kinda wide for 2 boats on one car. This seems pretty complicated and guaranteed super noisy in the wind with or without a boat. Would you take this contraption off when you're not boating?

Ropes would be your friend here unless you have bad shoulders or back. Flat on the bars upside down. Saddles and minimal tie down might help secure the boat to get from inspection to ramp.

I only have to drive one mile to the lake. Wind noise isn't a concern in this case.

The van is too tall to lift a 65 lb kayak onto it without a ~10 in platform to stand on. I used to have a mid-size SUV that was the perfect height. I could lift the kayak single-handed, rest the edge on the bars and slide it onto the car. The van has made that impossible (or more complex). And these inspections are a pain the ass. If you don't have a rig like the one on the video they make you bring the things all the way down to the ground. Imagine a line of ten or more cars at 6 AM waiting for inspections. Nobody is happy about it.
 
I think there some trick here about having the linear guides separate from the pivots, but getting the pivots to operate after a certain amount of extension. The other complex bit is locking the rack in the inboard transport position but here you could trade greater simplicity for being less idiot proof since you'll be the designer operator. Eg you could lock the slides down on the other side of the car so as to not over stress the pivots.
 
I’d look in a different direction than the slide arrangement.

Those pictured racks are slick designs which are well executed but...
It makes my head hurt thinking I would copy them.
“Don’t build it if you can buy it."

I would go instead with a ‘C’ profile of some sort.
Outboard is a pivot pin at the root of the C frame and rotation out carries the boat in an arc which lands it alongside the door windows.
I am thinking a self stowing guy stops travel but a rigid ‘stop’ could serve as well.

I will mull it over as I drag through my day and draw something up if if get it sorted.

Those straps the guy spends so much time showing off are the weakest part of the design and foolishness itself.
Sort of an afterthought after the design was done- "Oh shit we have to tie this down- lets get some webbing fast."

For some reason the buckles are supposed to make up for the PITA those straps are....
And the whole bloody design is way too high with the mount stack and rails...


Essentially you are designing a pair of davits- these have been around for centuries- look about a bit and you will find there are many types outside of the standard jib crane.


Edit-

Product of first sip of coffee as I start this miserable day...

The frame is locked by a spring loaded tab which snaps into a recess on an inboard plate on inside of base rail.
Outboard is a toggle which is grabbed and pulled to free the tab and allow the frame bottom to lift and rotate.

This design will be fully patent protected when I get it done so all of you keep your traps shut about it...

Second sip of coffee..
Rotation of frame is through 180 degrees, vertical column is set inboard of pivot pin by clearance allowance to vehicle side so as to not require long bed rails carried outboard as per the lame commercial rack you posted..
(and mulling it over on the third sip of coffee the "lock" for travel can simply be arranged by placement of the pivot so interference occurs to stop the frame rotation- simple and effective..)

Note on the design process- you need sufficient hubris to KNOW you can do a better job than the average idiot who designed something you can buy otherwise you will never bother to build anything...

I have a beautiful VCP sea kayak which hasn't seen any use in some years- I need a rack as well.
 
Before reading your reply I was going to suggest what a friend did for his canoe which is rig two wooden folding ramps that quickly connect to the rack ends and allow him to slide it down an incline. The part about the inspection nixed that idea.

If it were me I'd probably just use Unistrut channel for the racks with Delrin padded carrier slides (of 2020 extrusion?) and locking knobs to secure while traveling. Heavy duty hinges at the end of the channels with provision for the carrier to slide past it until the weight balance makes it tip.

Easier to imagine than describe but with a little mocking up probably wouldn't even need CAD except for the few machined parts. Don't overthink it if you're only going one mile and simply trying to satisfy inspection requirements.
 
I’d look in a different direction than the slide arrangement.

“Don’t build it if you can buy it."

I wouldn't build it if I could buy it. At this point it seems it might be difficult to even find these used. And, of course, when you buy used you might be buying a project.

What I want to try and do is build the dumbest and simplest thing that I can throw together to make inspections at the lake painless.

That's the variable here. If you exclude that I have no problems. Just two pipes across the top of the van and I can easily get a couple of kayaks up there on my own using a small platform to get a few more inches of height. I can dead lift 250 lbs, a 65 lb kayak isn't a problem.


I have a beautiful VCP sea kayak which hasn't seen any use in some years- I need a rack as well.

Thule has an even more complex solution that is slick but, man, check it out:


Can't get these either.

Of course, the other issue you start to run into very quickly is that these rigs have "Please Steal Me" written all over them. Two sets of these (Thule or Yakima) with all the widgets and gadgets will easily reach $1,500 to $2,000 on top of your car. Whew!

I think I would want something that is super simple to remove and store with the kayaks. All that should be left up on the vehicle would be either nothing (it looks stock) or just the cross bars.
 
How about something on rollers that you can slide off the rear of the van? Nothing fancy, set of wheels front and rear, rides a channel the length of the van, front set is constrained so you can't just slide the whole thing off the back and into your face... Roll it straight back, drop the back end to the ground, kayak can be inspected, push the whole thing back up on top, strap the front down so it can't roll off the back.... I hope that explains the stupid idea in my head well.
 
Don't overthink it if you're only going one mile and simply trying to satisfy inspection requirements.

That is precisely why I decided to post for opinions here. I am REALLY good at the overthinking part. An expert, really.

I was also thinking about a potential solution using Unistrut. It seems it could be a simple solution (and I have some of it laying around).

I happen to have four of these trolleys on the shelf:

McMaster-Carr

This is the one I have on hand:

McMaster-Carr


That said, I am imagining a solution using a couple of the smaller trolleys:

McMaster-Carr


I'll think about this some more and get a model put together over the weekend (and share it here, of course).

What I imagine is a ~3 ft sliding bar that the kayak would be mounted to.

Each end of the bar would have one of these mounted to it.

The crossbar on top of the van would be a 6+ ft Unistrut channel with the opening facing up.

The 3 ft bar with kayak would be locked in with a pin or two for safety.

Remove the pins and it slides out.

I just have to come up with a simple mechanism I'll likely have to machine that will then allow the moving bar to tilt down to an angle and stay there. I have a few ideas on that.

To stop the inboard carriage from coming off the end I'd just use a bolt across the 6 ft crossbar about four inches away from the end. This bolt would be behind the external carriage, which means it could slide out without any restrictions.

Some of the questions I have are things like: What happens if I pull out the kayak to just before the point of rotation and let go? Is the trolley and strut strong enough to handle the cantilever load of, say, a 150 lbs load out nearly three feet. Yes, the kayak weighs in at 65 lbs, but I can't design with that as a limit.

My guess is this won't be a problem. Easy enough to prototype and test.

Thanks for all the input (everyone). I have a sense this can be made using simple off-the shelf components and a maybe a few machined/water-jet parts.
 
How about something on rollers that you can slide off the rear of the van? Nothing fancy, set of wheels front and rear, rides a channel the length of the van, front set is constrained so you can't just slide the whole thing off the back and into your face... Roll it straight back, drop the back end to the ground, kayak can be inspected, push the whole thing back up on top, strap the front down so it can't roll off the back.... I hope that explains the stupid idea in my head well.

I think two basic ideas are surfacing, both using rollers and unistrut. One going slides off the side to emulate the commercial offerings and the other off the back.

The main issue I see with going off the back is that the kayaks are about 13 feet long. That's quite a bit of hardware and one heck of a cantilever case if you happen to stop before being able to rotate down. I would think this has the potential to rip the rack right off the roof. Which means you'd have to design it such that it never locks to rotation (no cantilever scenario). Not impossible. Need to think about it.
 
40 seconds in shows the power ladder rack in motion.

Oh, I really didn't need to see that. I can easily go off in that direction and shop up at the lake with a van with two robot arms mounted on the roof that lower and raise the kayaks with a button. Please don't give me ideas like this. I am that crazy!

:)
 
I thought it looked pretty cool in motion. Of course the truck was designed around that and the pump. Maybe buy a used fire engine. Some one on this site has one he is converting into a overgrown pickup for hauling machines. Might be good for picking up girls at the lake. Only "hot" girls allowed
A wheel chair lift might be a better start point.
Bill D
 
I can't help with your brainstorming but wanted to add this. I have a friend who my son works with. He was co-owner of Yakima, is a engineer and while he probably didn't design the rack you're talking about, he did many of the earlier versions when Yakima was still based in Arcata, CA, The work he does now has all the same earmarks to the work he did when he owned Yakima... custom aluminum extrusions, injection molded pieces, rubber over-molded stuff..just like roof racks..but different. He certainly doesn't have to work, but loves what he does.:)

Stuart
 








 
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