Getting Trollied

[Screwdriver]

It does look good thanks. Here it is almost done.

"Almost" despite being finished now because the chap popped over yesterday, paid a handsome amount without batting an eye and wants me to do more! It needs some sides making up and a shorter handle.

I'll do those at cost...

 

[davemill]

That's specifically what the customer wanted

Nice work! But you have a customer willing to wait two years?

 

[cheb]

Nice work! But you have a customer willing to wait two years?

The pace of life is slower over here, we try to avoid rush jobs

 

[Screwdriver]

Nice work! But you have a customer willing to wait two years?

I do a lot of odd jobs for this chap who runs his own Tree Services company. I fix any broken bits, straighten bent shafts etc. It's the only time my very casual approach to low cost repair really pays off. He keeps coming back and I'm more happy to get repeat business than to make a quick buck and never see anyone again. I was worried that this repair (several hundred quid) was a bit toppy but it was always going to be a bit of a nightmare working with rusty old seized parts. Better to give the money to me than send it to the CCP....

As I think I mentioned earlier, he works around Ealing so I often see him pass in the van. It did become a bit of a thing I'd say "I haven't done it yet" he'd "reply don't worry about it". Then he said he needs it.

Even the "simple" sides are going to be a head scratcher. I tried my best to talk him out of it but this is what he wants:

The three sides are connected to the four corner posts. The narrow front panel is hinged so that they concertina up as shown. But the posts drop into the corner sockets so the obvious problem is; when you try to lift the entire assembly out, all four corners have to lift at the same time or they will rack and jam. He wants the sides to be hinged and connected so that it's all one piece.

I believe I have a solution but before I share it, I'd be interested to hear any other ideas. The three sides must be permanently connected and form one giant hinged assembly. The posts drop in quite snug into the sockets but lift out easily enough and with two people would be easy to lift out in one go. One person would struggle and that's the situation I need to address.

 

[MattF]

Make the posts at one side slightly larger diameter, & have a secondary post within which slots into the sockets. All you need then are slots in the outer post tops & pins through the inners to go in the slots of the outer posts. Lift & rotate the inners to drop down & secure else retract.

 

[Screwdriver]

Make the posts at one side slightly larger diameter, & have a secondary post within which slots into the sockets. All you need then are slots in the outer post tops & pins through the inners to go in the slots of the outer posts. Lift & rotate the inners to drop down & secure else retract.

Interesting idea which is sort of an inside out version of my thinking. Clearly there needs to be a sliding hinge somewhere to allow the locating pins to engage/disengage without racking the entire assembly. I was thinking of literally just having the folding front section slide up and down on the posts.

As usual, the final design is constrained by materials on hand which is basically this:

The green tubes are connected by a waisted section which slides inside to lock the tube together. That narrower section also fits the sockets on the trolly exactly. They also have ball detents which sadly, I don't think I'll be able to use in this application. The grey tube fits inside the green perfectly which helps and would be ideal for the idea you present.

I have been asked to keep weight down to a minimum so have not yet decided exactly how to make this work but I like the idea of having an inside sliding hinge. Food for thought...

 

[Screwdriver]

So this is what ended up happening...

hmm. imgbb is down and so are quite a few other web services by the look of it. Could be some big news on the horizon. don't ever remember seeing so many issues on Is it down etc.

I'll attach this one:



As you can see from the video, the inner pipe forms a hinge attached to the rear folding section. Obviously one side is hidden to show how the front folding hinge is secured. When complete, the two sections will be joined by a hinge in the middle to connect both sides.

I will make it zero clearance and see if I can still lift out (ideally) the front first, fold the two ends together then pull out the two rear uprights. If it "rack" and jams, the design allows me to cut away a little clearance for the sides to slide up the hinge leaving the front folding panels in place. It's the old maxim: if you can't make it perfect, make it adjustable.

If the side panel lifts out without moving the folding section (you'd have to lift it by both side handles) then it can't jam up but it does make the assembly a little less "solid" when it's folded away for storage. There are some strips of ply in the middle of each side both for strength and to allow both sides to meet flat when folded. The handle slots will line up to allow easy handling.

So that's the plan and despite taking way too long thinking about it, it took only moments to make. Just need to knock up some tabs for bolting the panels to and then blow a few holes in it with the MiG.

 

[Screwdriver]

Looking for some advice from people in the know.

I am planning on welding those little brackets/tabs onto thin wall pipe. The tabs are about 1mm, pipe is about 2mm. Gonna MiG them in place and here's the question:

What is the preferred method for connection? It feels like just welding a thin tab onto a cylinder will mean all the strength has to be in the weld. Should I put a small bend to form a ledge which I can weld on with a greater contact patch? Maybe even some holes so I can plug weld onto the pipe.

They will be bolted though with 6mm roofing bolts to 12mm ply. Also wondering if I might even get by with a few good, solid tacks rather than fully welding.

 

[Turbo]

Looking for some advice from people in the know.

I am planning on welding those little brackets/tabs onto thin wall pipe. The tabs are about 1mm, pipe is about 2mm. Gonna MiG them in place and here's the question:

What is the preferred method for connection? It feels like just welding a thin tab onto a cylinder will mean all the strength has to be in the weld. Should I put a small bend to form a ledge which I can weld on with a greater contact patch? Maybe even some holes so I can plug weld onto the pipe.

They will be bolted though with 6mm roofing bolts to 12mm ply. Also wondering if I might even get by with a few good, solid tacks rather than fully welding.

Just be careful not to leave a bump inside the tube otherwise it will no longer swivel or slide.

I suggest some practice on spare tube.

 

[Screwdriver]

Just be careful not to leave a bump inside the tube otherwise it will no longer swivel or slide.

I suggest some practice on spare tube.

Hmm. Good point. I hadn't thought of that.

Maybe I should just stick to tack welds.

 

[Turbo]

Weld your tabs at the open ends of the tube so that you can get in with a powerfile or die grinder to remove any bumps.

 

[Screwdriver]

Looking at the model, it's only the bottom of the folding doors where there may be an issue. The inside pipe is a short section that only slides into the outer by 60mm. I can get to that with a powerfile if necessary.

 

[Screwdriver]

Yeah, I know. Who spends this much time on a stupid trolley...

Anyway, despite the fact we knew it wouldn't work, it is all together now and doesn't work.

Made up all the posts and "hinges".

Printed a cheat sheet for the six off door mounting brackets. The Gabro notcher bites a 4mm slot out of the sheet hence the "roadmap". Also cutting a dead straight line is the most efficient way to make all six brackets in one go, effectively making 3-4 cuts in one.

Ok bad example, here it is making only two cuts in one go but ykwim.

Same deal with the side post tabs. Once installed, line up with clamps, drill through for bolts.

I didn't even have to hide all the terrible welds under the only good two.

(it happened all by itself, lucky me...)

more...

 

[Screwdriver]

Bit of a faff fitting the hinge elements because the top brakcet has to come off to slide them on.

Final assembly: Couple of piano hinges and hinge elements installed with no clearance.

...and once all assembled, just pop the sides out and fold up for transport....

Hang on! I thought you said it didn't work? Well. It too about half an hour to prise those sides off. The whole assembly tilts and racks in the holes and locks solid. I had to go around with a set of wedges and gradually lift each corner!

Pretty sure I can fix that problem and also pretty sure it will easily lift out with two people. No easy way to test that theory...

So it is "done" and I just need to faff about with it. Take half an inch off the socket, maybe add half an inch of clearance to the hinges (so the rear panel can lift up without trying to lift the whole side)

I need to red oxide all the exposed steel/welds and chop off the roofing bolts. Put in a couple of lifting holes.

Yes it is horribly overlong for a trolly but the customer gave me a challenge. Make this thing do what he wants and not what I tell him is a better idea (i.e. just have three interlocking sides!). So this is as much a "puzzle' to be solved as it is a simple matter of knocking up a simple trolley.

If it ever really works, I might even do a quick video.

Don't hold your breath...

 

[Beanwood]

...how about.... replace the piano hinges with 'normal' hinges, perhaps joined together by a single pin that can be extracted from the top, so each side would lift independently once the pin is removed?

 

[Screwdriver]

...how about.... replace the piano hinges with 'normal' hinges, perhaps joined together by a single pin that can be extracted from the top, so each side would lift independently once the pin is removed?

I did ask when he first mentioned the idea of folding doors etc. I wanted separate panels that clip together but he was adamant; they must be permanently connected and fold as per the above.

Anyhow, I eased the sockets, deburred, greased them but to no avail. The sides slip in and out easily witout the hinge connected, with the hinge the whole thing racks and jams solid. So I was left with three main options.

1. Make the front folding hinge with a 50mm sliding pivot so each side could lift up without moving the "doors"
2. Cut a slot in the door hinge so the sides could lift up and the large door "hinge" tabs would slide up into the slot
3. Cut the socket fitting off and use a sliding "bolt" action at the rear for each side (like a door bolt)

I decided the easiest/best option was to go with a sliding bolt which - a conclusion I share with @MattF. I didn't really want another "mechanism" but the construction is so solid (which is a good thing!) that the only other solutions I could think of would add a lot of slop remembering this thing is being dragged across gardens and fields bouncing all over the place...

So I cut the ends off only to discover the swaged/reduced diameter section went quite a bit further up inside the green tubes. Only solution was to turn them upside down so the inner "pipe" could slide in and out of the end. I lucked out on one side which was rotationally symmetric so I could reuse the existing tabs in the existing holes.

The other side was 5-10mm out and I had to cut off the tabs and re weld them.

Shame because this is actually one of my best welds!

There it is gone:

With the outer green pipe inverted, I can use a short section of inner pipe like a door bolt. Will need to cut a slot etc. but this was the simplest solution. Also with the bonus being, once both sides are "free" you can move them together and the structure will still stand because the front hinged door part is still stuck in the trolley. Then both front uprights can easily be pulled out and folded together. Sort of an operational bonus because you wouldn't want to be fiddling around at the other end with the hinged part flapping around. I might even fit some sort of simple clip or lock to hold the assembly flat.

Meanwhile, I had been meaning to do this so that I can start permanently attaching stuff. Ordered up some lock nuts for the roofing bolts which can be trimmed to length once they're permanently installed.

Once again, I am slightly panicking over the cost of all this extra effort. I figure it's a custom build for a customer who knows exactly what he wants and even with recycles parts, that don't come cheap.

 

[Screwdriver]

I think it's done now. Made up a few bits and bobs for the sliding bolt to replace the ends of the uprights.

Nothing fancy, just a stepped rod to go into a slot in the uprights.

Couldn't find a 12mm drill bit(!) so it needed another small step down to clear the slot.

Works better than I expected.

Just need to cut another little slot for it to tuck away against the sides (like a door bolt). Then it's really nearly done. Wait for some lock nuts to replace the square nuts on the roofing bolts. Cut to length and cut down/weld up the big yellow handle so that it can manoeuvre in tight spaces. oh and maybe add a bit of reinforcement to the door hinge, put some extra thickness behind the piano hinges so I can use longer screws and create a more positive stop. I might add a little latch too. (and add some locking pins to the uprights).

 

[Screwdriver]

This is going on some now isn't it...

Another day another problem. So I gave the slot an extra drop so that it fits flush to the sides.

No pics of the issue but I tried to open the thing up so I could cut down the bolts. The excess length meant I couldn't fold it flat. First time I tried this, I discover it's a lot heavier and awkward than you might think. I managed to twist one of the tabs. Then I discover this has knocked everything out of alignment. The drop bolt needs to line up with the hole perfectly within 1mm, maybe 2. That's why they're there in the fist place because any misalignment means no-go.

So in this shot you can see I had to put in a strap (I only had 1.5mm flat bar) to make sure if nothing else, at least that dimension will be stable.

Then after cutting off the excess length, the magic happens.

It does go flat but I didn't want to drop it.

I just need to come up with some method to clip them together. Don't want them unfolding and twisting the brackets again.

Now all that's left is to shorten the handle...

 

[Turbo]

Through time that plywood will warp, especially if it gets wet and your frame will no longer line up with the holes!

You might be better making a steel frame and cladding it with wood or weld mesh.

 

[Screwdriver]

Through time that plywood will warp, especially if it gets wet and your frame will no longer line up with the holes!

You might be better making a steel frame and cladding it with wood or weld mesh.

You're not wrong and I did txt the client to get a sheet of 12mm marine ply (and get one for me!) but he gave me this disaster instead. Old, dry, damaged, full of rivets it's why I had to treat it with something, anything just to stop it falling apart. It's also why the entire cart is designed to be very easily maintained (upgraded?) with better material. I think the steel strap will stop the only critical dimension from moving. I'll have to whip it off to rustproof it and I may even stick it back on with a tack of weld.

The metal I used for the tabs is far too weak but I didn't think it needed any real strength. It should just hold the lightweight ply in place. They are not strong enough to support an entire side if it happens to swing open like a door while attached to the base! All they do is buckle and twist slightly but it was enough to throw the alignment out.

If this had been three separate panels (like it should!) I could have completed the job in under a day. As it is, this is going to cost £££.

Hey ho. The customer is always right.