RV Baby Car Seat

ghhardin · 03-16-2019, 09:19 PM

New Berkshire 40C owner and new father. We are getting the rig ready and on our first outing with our 7 mo, we found that the car seat did not work well at all. We dropped the kitchen table and juggled the cushions and utilized the seat belts but could NOT pull them tight enough. The car seat rocked both sideways and fore & aft. Nervous parents..
Today, after contemplating how to improve the situation and wandering around Home Depot for a bit, I came up with this three position mounting system that allows us to position the car seat . The red Husky locking Tie-Down straps secure the 1" X 18" wide plywood down to the metal frame for the seat belts on the aft side of the rig and on the fore side I installed eyelets in wood frame for connecting the straps. It is not going anywhere..
On the board itself, I installed three sets of anchor points with carriage bolts. This should give us options to position the car seat. Right now the car seat has to be setup for rear facing but this setup should also work for front facing.

ghhardin · 03-16-2019, 09:25 PM

Side view

Eagle5 · 03-16-2019, 09:58 PM

Interesting. Good work. New dad here myself. My boy just turned 2 but we’ve been RVing w him since he was about 7-8mo old so I know the feeling. We have a 2019 34QS now and I guess it’s set up a tad different then your 40. I dug below the couch cushions and found frame mounting points and was able to strap in the seat securely there.

Your setup looks legit though! Good work. Glad it’s secure. Makes the trip more enjoyable.

Cheers

ghhardin · 03-17-2019, 08:24 AM

I was able to dig down to the frame mounting points (where the belts attached) and attach the car seat but the car seat never felt tight enough side-to-side or fore and aft. Very nervous wife..
It looks like our dinettes are a little different. Our back rest is a two-piece versus a single cushion. I am not sure the two-piece style is better than a single functional backrest.. Also, its a bummer that my dinette cushions do not create a fully flat "bed". There are gaps ;( It will make for an interesting play area for our little one..

jimmoore13 · 03-17-2019, 06:21 PM

Clever...good job.

I was an early adopter of seat belts and car seats (for my now 46 year old son). I adapted a number of vehicles including an MGB-GT and numerous cargo vans.

Perhaps the most crucial part of mounting a seat belt was "fender washers." Invariably I would drill through the floor of the vehicle and use a small stack of fender washers to spread the load. I'd start with a 3/4" fender washeer then down to 1/2"...the size of the bolts I used to anchor the belts, then top it off with a lockwasher (nylock nuts didn't exist). Probably overkill, but I had no guidance, and I was an Ironworker, so, bigger is better.

The fender washers spread the load on a simple hole through the floor.

Seat belts and anchors are much more readily available and far more sophisticated these days. No doubt, you could replace the factory lap belts with something that cinches up more tightly on your child seat. These adapters could be helpful if you need to tie into a frame member.

Soon you'll need a "tether" to hold the top of a forward-facing seat and so on, so customize to your heart's content and make something that will really fit and keep your precious cargo secure.

PS, just make sure your adaptation is fastened securely so it can't become a missile in your vehicle.

ghhardin · 03-17-2019, 08:53 PM

Thanks for the links....

I agree with the washers... The aft straps are wrapped around the existing frame for the seat belts - truly bombproof. The forward straps are tied into the woodframe using BIG washers... The entire rig could be upside down and that car seat will be right where it is ;D

In a frontal impact, it is all about the shear strength and I am confident in the shear strength of the four carriage bolts...

Oscarvan · 03-17-2019, 09:31 PM

You're assuming the coach maintains integrity. You probably shouldn't ever go to an RV junk yard. It doesn't take much for these things to completely disintegrate. That said, tying little ones down is good practice.

ProfChuck · 03-18-2019, 07:53 PM

Looking at your pictures, I would be very worried about the hold down's that you are hooking the seat to. In a crash, you will be putting extreme pressure against those hooks. Make sure they can hold the weight (force). It could be 600 lbs. or more against those hooks, so the hooks and the bolts holding them down need to be very strong. Hopefully you will never need them, but, in the event of a rollover or crash, just think of that weight against those hooks. If you look at swings in parks and the size of the bolts holding them in place just for swinging, they are much thicker and usually a high grade of bolt and chain. You certainly don't want that mount to come loose and either hurt your child or become a flying projectile and hit someone in the front. Maybe I'm just a worrywart. Be safe.

ghhardin · 03-20-2019, 02:19 PM

I think I have it well engineered...

Each hold-down is rated at 300 lbs each- two are connected to the seat for a total static hold power of 600 lbs. The red load straps are each rate at 400 lbs each and there are 2 for a total of 800lbs of static hold power... So the minimum static hold down load is 600 lbs...

That being said, you cannot escape the physics of Dynamic Loading..
F=MA, Force = Mass X Acceleration
Additionally, some elasticity is a good thing as it can absorb some of the energy versus directly transferring it.

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