Fort Ladder / Merging Threads

Nickp said:

You're going to need some bracing to keep it from racking...

What is your plan for keeping the stringers from spreading...?

Just looking at the angle and the hand-holds, you might check that the hand-holds are not too far out for comfortable climbing...it almost looks like a child going up might be leaning too far back to hold the stringers...just wondering...

Lookin' good...

Click to expand...

I had not considered racking. It will be mounted permanently at the top with two 1/4" lag bolts on each side, about 18" apart. I don't see much opportunity for it to rack. I could add a cross brace, if it becomes a problem.

I was assuming the screwing and gluing the rungs every 12" would keep the stringers from spreading. Three pocket hole screws from the underside on each end of the rungs plus gluing them in place. I decided on the pocket hole screws so the screws would not be going into end grain as they would if screwed through the stringers into the rungs. I could add a couple of those too, which I considered, but dismissed as being overkill and unnecessary.

You may have a point about the handholds causing a child to be too upright. I will not be surprised if the kids ignore the handholds and just grab the rungs when climbing. If it looks awkward, I'll encourage her to use the rungs. If so, the handholds will just become decorative :smile: I put the same 1/4" radius roundover on the rear/top corner in anticipation that the rungs would be used instead of the handholds.

Rick

RickKr said:

I had not considered racking. It will be mounted permanently at the top with two 1/4" lag bolts on each side, about 18" apart. I don't see much opportunity for it to rack. I could add a cross brace, if it becomes a problem.

Rick

Click to expand...

ornate gussets under the treads..
solves racking and spreading in one shot...

Rung Pockets Done

Results of tonight's work, finished the other 15 pockets. I had to flip the fence on the pocket routing jig for the opposite stringer, to have mirror images.

As I was working on the second stringer, the bit seemed to be dulling, requiring more pressure to move it through the wood and having tear out on the exit, which I really hated as it is the upper side where little hands might scrape. It wasn't until I got finished and inside and saw the photos I took. One, showing how the new dust hood completely encloses the open side of the router base, revealed what I think was the cause. The speed setting had gotten turned down to "5", visible in the photo I was going to post about how much I liked the new dust hood. Both symptoms make sense now and the bit is probably not nearly as dull as I was thinking.

Hardly any dust/chips escaped, except at the start when the opening in the base overhung the fence, allowing a little bit to escape. I had noticed yesterday that chips were flying out of the 3/8" edge guide rod mounting holes. I plugged them with 3/8" dowel.

I was thinking it was ready for screws and glue, but now I want to think about making gussets.

Rick

the bit is probably not nearly as dull as I was thinking.

Click to expand...

clean dress the bit anyways....

and this is what I mean by clipping...

....

Stick was talking about nipping the the sharp tips off the gusset. The gusset is an isosceles triangle with leg, leg, and a hypotenuse. He meant nip the tips off perpendicular to the legs.

I don't think I would trust the pocket screws to keep the sides from spreading. I don't trust pocket screws for much but I know lots do. I also don't see much opportunity for racking. The top will be firmly attached to a non moving structure and the bottom will be on the ground. There will be some flexing though and that's why I don't trust the screws. In a traditional wooden step ladder you only have 3/4" thick steps but they are supported by steel rods which help support the load but also keep the sides from spreading. The angle brackets Stick suggested would do that too but I would use machine screws and locking nuts to attach them so that they couldn't loosen over time. I don't know if you really need the gussets and they might get in the way when climbing. I would expect the ladder to flex a bit and some structures need to be able to flex. Too rigid and they'll self destruct over time. An airplane is a good example of that.

Cherryville Chuck said:

Stick was talking about nipping the the sharp tips off the gusset. The gusset is an isosceles triangle with leg, leg, and a hypotenuse. He meant nip the tips off perpendicular to the legs.

Click to expand...

I believe I am thinking the same, but here is a drawing of what I am thinking of, with radiuses, 1/2" and 1". I am inclined to the 1" radius. The 1/2" seems to get lost.

Cherryville Chuck said:

I don't think I would trust the pocket screws to keep the sides from spreading. I don't trust pocket screws for much but I know lots do.

Click to expand...

I know many do not like and/or do not trust pocket screws. I figured they are better than similar sized screws going through the stringers into the rung end grain, plus I was going to glue them. I realize that could make it too rigid, to your last point. I just don't see this ladder getting stressed that much, similar to your comment about not much racking. As you say, some need to flex, but I don't see this flexing that much (until "I" get on it :surprise.

Cherryville Chuck said:

I also don't see much opportunity for racking. The top will be firmly attached to a non moving structure and the bottom will be on the ground. There will be some flexing though and that's why I don't trust the screws. In a traditional wooden step ladder you only have 3/4" thick steps but they are supported by steel rods which help support the load but also keep the sides from spreading. The angle brackets Stick suggested would do that too but I would use machine screws and locking nuts to attach them so that they couldn't loosen over time. I don't know if you really need the gussets and they might get in the way when climbing. I would expect the ladder to flex a bit and some structures need to be able to flex. Too rigid and they'll self destruct over time. An airplane is a good example of that.

Click to expand...

I do not think the gussets will interfere with climbing, based on the drawing above.

I will think on the matter of using machine screws, etc. I have a little time before needing to make that call.

Rick

clip instead of radius...
the sharp turn will make a water let (drip point)...
as where water will follow the radius...
radius the long outside edges of the gussets...

thru screw the steps/rungs/gussets w/ RSS/GRK screws from the outside of ladder stringers...
https://www.grkfasteners.com/products/rss-rugged-structural-screw
or headlok structural screws by timberlok...
https://www.fastenmaster.com/product-details/headlok-heavy-duty-flathead-fastener.html
use construction adhesive like PL Premium instead og glue... you won't regret it...
https://www.loctiteproducts.com/en/..._premiumpolyurethaneconstructionadhesive.html

you get your flex...
you get serious strength..
you get water proof end grain..

If this goes up more than 10 ft, I think a cage is in order. Falls from that height WILL break bones or cause other injury depending on how they land. Start the cage at 5 or 6 feet, and wide enough so an adult can get through comfortably. A cage will spoil the ship's ladder look unless you make it with a very open look. I bet many kids will see it as kind of a tunnel and enjoy climbing through it.

Another possibility would be to put some soft landing under the ladder. I lived next to a park once and they laid a layer of rubber particles, kind of like pea gravel, under the play areas to soften the landing if a kid fell. You could probably use wood chips for this, but there will be splinters, and it will deteriorate over time. If you use rubber particles, the base for the ladder still needs to be set on something pretty solid, perhaps a short chunk of 2x6 or 8 of synthetic decking that won't rot.

The landing pad, if you do that, would be 4-6 inches thick and wide enough to assure a falling child would land on it. Here's a link for playground safety mats. https://www.greatmats.com/playgroun...playgrounds&utm_content=Rubber Playground Mat

That ladder is too pretty for a cage unless it's tall enough to cause more serious injuries if a child falls. So I'd go with the padding. If this is where many children will find and climb it, you will have created an attractive nuisance and could have some liability issues. If it's in an enclosed back yard, the homeowner insurance MIGHT cover injuries. Damn Lawyers pop up everywhere, don't they, like weeds. Sorry to bring this up, but I remember when the playgrounds were upgraded from dirt, the city had put them in to cover their financial behinds.

Putting my little guy hat on, if I had a ladder like this, I'd HAVE to climb it.

Jig for Keeping Rungs Square

I really appreciate the discussion and idea for fastening and gluing the rungs for this ladder. Thank you all. I will go with the construction wood screws and construction adhesive. I know I've seen screws like that at the local hardware stores but I have not looked at what sorts of construction adhesives they carry. I know the brands of screws Stick posted are NOT available locally, but one brand is at one store 50 miles away. Because of the rigid mount, I may not go with gussets.

So, moving on ...

I am thinking ahead on how to hold the rungs square as they are fastened/glued to the first stringer. I am thinking all the rungs must be secured to one stringer first and then the other stringer added in a second stage. It is possible the rungs would mount fairly square without any jigging (is that a word? - sounds like a fishing action) because the pockets have been routed square bottomed and the ends of the rungs have been cut very square. But, I do not want to rely on that, solely. I would like to come up with a jig, large squares that can be clamped to the stringer and rung while it is being glued and screwed in place. I have a couple of the large construction squares and they clamp up okay with the stringer flat and the rungs sticking upward.


However, that is not a position in which I want to be gluing and screwing, from below. I am not confident that those squares will stay in place if the clamped up rungs/squares were laid over flat, so I think some blocks or something need to be attached to the squares for more secure clamping. I am okay with drilling holes in at least one of the squares for attaching blocks. Alternatively, it could work to clamp blocks to the stingers/rungs and then clamp the squares to those blocks, eliminating the need to drill and bolt blocks to the squares. But... that is a couple extra steps that may not work well with glue setting up.

Thinking further, glue and screw the two first rungs while laid flat, without clamping square. Then tilt it up so the rungs are upright and then clamp them square (as pictured) and let the glue set up. That could be done quickly and well within the glue working time (if not, I need to find a different glue as the final glue up of the second stringer is going to take much longer).


Follow that same procedure for adding the other rungs and use a lath to tack the others square, using the clamped square to align each rung, prior to tacking.


I am also starting to think about the entire gluing/screwing operation/sequence of once the rungs are all in place on the first stringer, how do I go about adding the second stringer and gluing/screwing all nine rungs? Will the working time of the adhesive allow for applying glue to all the pockets/joints, press the stringer on and then drive the screws? I am thinking that at this point the assembled first stringer and rungs can be laid flat on a bench or horses so the screwing of the second stringer could be done horizontally. I anticipate that holes for all the screws will have been pre-drilled in the stingers and the screws in place ready for driving into the rungs.

... OPEN THE FOOD GATES !!!

Rick