146 replies to this topic

[Daves956]

My plan is to build a support truck for the 959 Paris Dakar rally car. I started with this used Volvo FH12 semi and plan to base it on a flatbed trailer. I bent the ali sheet to be 8x8x8 and a little wider than the trailer on purpose. Here is where it all got started.

[Daves956]

These have already arrived.

These are on the way

[Daves956]

I did a bit of cutting today. The L shaped pieces are the lift columns and fit inside the C channel that will mount to the sides of the box. They will be fitted with the round stock for the pivot. Out on the bottom of the L will be a pin to cantilever the weight and stop the deck from going past 90 degrees. The long angle pieces are for the bottom edge of the box, to mount it to the flatbed.

The 2 center supports for the deck have been cut for the rotating pin and also will make a channel to slide in the second deck plate. With the second plate extended it will be around 14 inches long and 8 inches retracted. This picture shows them upside down.

The gearbox in the first picture is power for up and down. It's been modified from being 2 single side by side to a paired set with twin motors. A common idler was added to make them keep even speed and double the pulling force. No clue where it will be mounted yet.

[Daves956]

This is probably a better view of my plan so far. The C channel is deep enough to bolt through to the box and have room for the column to move. I cut steel spacers for the bolt points so as not to pinch when tight. I'll use hex head bolts because they'll look more correct.

I found 30 pound test stainless fishing leaders to use on the lifting end. Pre finished ends on them too.

It has to lift from the L bottom but it will be triangulated out to 6 inch area of the lift deck as well. For the triange, I'll be using the chain that comes with the trailer. If I add a small cable roller and short the chain to the mid point, most of the load will be carried out further with a cleaner lift operation.

So far this is all pure theory with no data to back it up. If anybody sees a big flaw in the plan, please let me know

[Skottoman]

This will be impressive for sure.... keep the photos coming.
Cheers,
Skottoman

[Daves956]

This arrived from Tower Hobbies today.

My intention is to put the trailer together and prove it's going to be a shelf queen. I have a hard time with the stick control and 3 channel doesn't help. Add a trailer to it and it should be enough to make me sware off driving it again. It will be funny, so it'll be starting the project off with a good laugh.

[Daves956]

The little plastic stays and posts have to go. I'll remake them in ali before I put the bed in. I wanted to see what I was working with and it will be a challenge to say the least. The dimensions are close enough that it looks like nothing already made will be scrap.

[bromvw]

Looking good Dave . If you can make this work it will be awesum .

[Daves956]

I've been looking at this and gathering up some dimensions to see what can work and it just dawned on me what a beast this thing is. The truck and trailer are pretty much 36 inches together and I'm planning a 14 inch ramp on the end of it. It's around a foot tall and when I do a swing out side for it, something like 16 inches wide. All in it's probably 20 pounds too. Much bigger and I'll be parking it next to my 1:1 car. Where I planned on putting it is only 46 inches long so now what?

[bromvw]

I've been looking at this and gathering up some dimensions to see what can work and it just dawned on me what a beast this thing is. The truck and trailer are pretty much 36 inches together and I'm planning a 14 inch ramp on the end of it. It's around a foot tall and when I do a swing out side for it, something like 16 inches wide. All in it's probably 20 pounds too. Much bigger and I'll be parking it next to my 1:1 car. Where I planned on putting it is only 46 inches long so now what?

Build a bigger Shelve

[Daves956]

Build a bigger Shelve

I'm not sure where I could put a 5 foot shelf, just for this truck.
Here's where my thinking is going on the rear gate/lift.

like that the lift is 14 inches long and collapses to just over 8

[bromvw]

Couple of thoughts . Will it be rigid enough ? How are you going to get the top section to power slide out ?

[Daves956]

Rigid enough, yes. It's 2mm aircraft grade and the slide is very tight. 2mm by scale is about an inch thick. On the auto slide, that and lowering it have cost a bottle of tylenol with no answer yet. I'm thinking a winch to lower it and hold it closed. the winch would look cool too and positioned right would be an engine hoist as well. The vertical drop from trailer to ground is around 5.5 inches and so is the extend length. If I use a small cable hooked to the trailer side center of the extension then run through a pulley at the end of the gate all you'd have to do is hold the other cable end on lowering to move the extension out. Release the hold and the extension would be free to move up and down with the lift. If the cable was a loop and held on an up stroke of the lift then it would retract or it might be possible to power it in and out by the 90 degree lowering of the whole gate and eliminate the hold and release on the up and down stroke of the lift. I've looked for a small rack and that sounds iffy at best, plus driving it would be tough. I could drive it out with a rod too, but then how do you bring it back? A fixed loop to the lowering cable so that as its swung up and down it slides it in and out. A bit of gravity at play on that idea and it would have to be on both sides but a possibility. So ya, if it were easy everybody'd be doing it.
I'll have to finish building the gate and mount it to the box to try some of these ideas.

[bromvw]

Rigid enough, yes. It's 2mm aircraft grade and the slide is very tight. 2mm by scale is about an inch thick. On the auto slide, that and lowering it have cost a bottle of tylenol with no answer yet. I'm thinking a winch to lower it and hold it closed. the winch would look cool too and positioned right would be an engine hoist as well. The vertical drop from trailer to ground is around 5.5 inches and so is the extend length. If I use a small cable hooked to the trailer side center of the extension then run through a pulley at the end of the gate all you'd have to do is hold the other cable end on lowering to move the extension out. Release the hold and the extension would be free to move up and down with the lift. If the cable was a loop and held on an up stroke of the lift then it would retract or it might be possible to power it in and out by the 90 degree lowering of the whole gate and eliminate the hold and release on the up and down stroke of the lift. I've looked for a small rack and that sounds iffy at best, plus driving it would be tough. I could drive it out with a rod too, but then how do you bring it back? A fixed loop to the lowering cable so that as its swung up and down it slides it in and out. A bit of gravity at play on that idea and it would have to be on both sides but a possibility. So ya, if it were easy everybody'd be doing it.
I'll have to finish building the gate and mount it to the box to try some of these ideas.

Dave is there any way you could have the lift extension mounted to rails and belt driven ? I'll try to explain . The rails would be fixed to the first hinged section of the lift ramp with the drive under mounted when the ramp is down . The extension is fixed to the belt and then travels in/out in the rails . Just a idea .
The only other way i can see to do this is to have the load demountable . It would be a lot of work but i think your well capable of doing something like this .I've also seen this build thread on another forum that might interest you
http://www.scale4x4r...a...9590&page=3

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[Daves956]

Dave is there any way you could have the lift extension mounted to rails and belt driven ? I'll try to explain . The rails would be fixed to the first hinged section of the lift ramp with the drive under mounted when the ramp is down . The extension is fixed to the belt and then travels in/out in the rails . Just a idea .
The only other way i can see to do this is to have the load demountable . It would be a lot of work but i think your well capable of doing something like this .I've also seen this build thread on another forum that might interest you
http://www.scale4x4r...a...9590&page=3

If I went to a belt drive it would have to be in the middle and roll over the front lower piece. It could be done but I think it would limit how close to the ground you could get and I'm not sure where you could put the motor to drive it.

The biggest problem is that it moves up and down so any force used to make it slide out has to be mobile and mounted to move with it or use the energy from some other function to accomplish it.
I'm sure there's a way but it just needs to be put together more to find out what can work

[Daves956]

This is pretty simple and I like that. One cable attached to the extension at the center near the trailer, out to a small pully on one of the guide rail outer ends. Back under the lift pivot rod and attached to the trailer or box bottom. When the lift travels down it pulls the extension out to 5.5 inches. At the same point of the pulley on one side attach the cable from the gate lift winch. When the gate is at approximately 30 degrees, gravity makes the extension slide back and is stopped by the lift pivot rod. No human interference needed. So simple it just might work, nothing fancy and gravity does most of the work. If you run the gate winch and the lowering motor at the same time the movement would be pretty smooth too. Small deal of having to cycle the lift to position it all for the car but that's nothing really. Kinda like a tommy lift that won't fold out unless on the ground.

[bromvw]

This is pretty simple and I like that. One cable attached to the extension at the center near the trailer, out to a small pully on one of the guide rail outer ends. Back under the lift pivot rod and attached to the trailer or box bottom. When the lift travels down it pulls the extension out to 5.5 inches. At the same point of the pulley on one side attach the cable from the gate lift winch. When the gate is at approximately 30 degrees, gravity makes the extension slide back and is stopped by the lift pivot rod. No human interference needed. So simple it just might work, nothing fancy and gravity does most of the work. If you run the gate winch and the lowering motor at the same time the movement would be pretty smooth too. Small deal of having to cycle the lift to position it all for the car but that's nothing really. Kinda like a tommy lift that won't fold out unless on the ground.

Now i like that idea . Its simple but effective .

[Percymon]

This is pretty simple and I like that. One cable attached to the extension at the center near the trailer, out to a small pully on one of the guide rail outer ends. Back under the lift pivot rod and attached to the trailer or box bottom. When the lift travels down it pulls the extension out to 5.5 inches. At the same point of the pulley on one side attach the cable from the gate lift winch. When the gate is at approximately 30 degrees, gravity makes the extension slide back and is stopped by the lift pivot rod. No human interference needed. So simple it just might work, nothing fancy and gravity does most of the work. If you run the gate winch and the lowering motor at the same time the movement would be pretty smooth too. Small deal of having to cycle the lift to position it all for the car but that's nothing really. Kinda like a tommy lift that won't fold out unless on the ground.

Definitely sounds like you are onto something there Dave.

One thought I had driving to work this morning is could you use a very thin cd/DVD player drawer mechanism to slide out the tail extension?

[Daves956]

Definitely sounds like you are onto something there Dave.

One thought I had driving to work this morning is could you use a very thin cd/DVD player drawer mechanism to slide out the tail extension?

That would only be around 3 inches travel and I need a minimum of 5 to make it long enough to be under the 959. I thought about some kind of lever design but I just don't have room for a drive motor on the platform where it would need to be.

[Percymon]

That would only be around 3 inches travel and I need a minimum of 5 to make it long enough to be under the 959.

3" ?? all my players (bar the quirky Naim) comes out 5" to accept the disc in full ??

[Daves956]

3" ?? all my players (bar the quirky Naim) comes out 5" to accept the disc in full ??

Your right, I was thinking of one off one of the laptops for some reason.

[Daves956]

A little progress, enough to be able to try a few things.

Closed and on the trailer.

Completely opened and down.

And the pit crew is here from HK. The white block is a generator that showed up.

[Daves956]

About tipped the trailer over backwards but it all held.

The chain from the trailer won't work, it's not strong enough to lift with.

[bromvw]

About tipped the trailer over backwards but it all held.

The chain from the trailer won't work, it's not strong enough to lift with.

How about using fishermans trace cable ? That should take the strain ok .

[Daves956]

Just testing the idea with the cable. It is too sweet, works like a charm. It's not routed correct but I wanted to try it. You can see the itty bitty cable from the center extension and eventually just hooked over the end of the C channel.

I'll get back on the trailer itself, now that I have an idea and some dimensions to go with.

There is a lot of final fitting to do on the lift and a slew of bolts to put in. Still no real idea on where to put the gearbox for the lift. I need better chain, a 5 channel reciever for the trailer, winch and figure out if an ESC will run the gearbox. The 5 channel is so the car and trailer can be run at the same time on one transmitter. Right now the 959 is on a single stick of the truck transmitter. It's kinda tricky to drive but so is the truck. If I ever forget and leave the truck on with the trailer and car on, it would be pretty spectacular. There will be at least 7 channels in use with some overlapping. Shift gears in the truck and the gate opens on the trailer sort of thing.

With the ali pieces and a boatload of bolts the current price tag is at 1150 and still climbing but should taper off around 1250 or so.