The RedBurb

[AugustDiesel]

“Okay, that’s also cool, but we want to know how you’re going to raise this thing!”

I also have an answer for that.

1.75 years ago, @KirsL gave me the idea of using a linear actuator to raise and lower the tire rack. I jumped on board and quickly ordered an actuator from Progressive Automations. It’s waterproof with IP68M/IP69K ratings and has a load capacity of 450lbs. It’s compressed length is 20” and it’s extended length is 36”, so a 16” stroke. Should be plenty for lowering the rack and compressed length is perfect for ride height.



The plan is to have another set of tabs welded to the top bumper tube right above the hitch and then at the other end will be a set of tabs welded to a plate @stan1688 cut out for me that will be bolted to the wheel/studs on the rack. With the motor at the tire end, there is just enough space between the tire and the doors for this to work.



The actuator will be wired to a toggle switch mounted to the bumper which will provide the power for the action.

This actuator has been on the shelf for nearly 2 years, so I’m excited to put this to the test. Hopefully I’m not pushing the limits of the load capacity, but we will see.

As for how the rack will be supported once lowered, I’m going to whip together a leg that will be kept stored in cab and can swiftly latch in place to the top of the rack and support the hole rig once down on the ground. Perhaps hard to visualize, just have to wait and see.

Lots to do over the weekend and it’s questionable as to if I’ll get it all done because I’m running out of steam and dry weather.


Andy

 

[mrk5]

I noticed that bar on the roof in some earlier pics and I figured it had a part to play. Interested to see how the actuator works.

 

[ktmoutfront]

I hope that actuator works. I have tried doing things like that in the past. You lose a lot of pulling power as the actuator breaks from a 90 degree angle to the pulling plane on each end. You may have to help it once it is part way up.

 

[AugustDiesel]

I noticed that bar on the roof in some earlier pics and I figured it had a part to play. Interested to see how the actuator works.

I hope that actuator works. I have tried doing things like that in the past. You lose a lot of pulling power as the actuator breaks from a 90 degree angle to the pulling plane on each end. You may have to help it once it is part way up.

It definitely won’t be as easy as bolting it together and sending it. @mrk5 last post prompted me to go out and do a test and I discovered that the actuator, in the down position, only needs to extend a couple of inches, and does not hold the rack at all when in the upright position. Just pivots with the rest of the rack. When I tried to raise it, it just pulled the whole rack closer to the truck, without actually raising it.


View attachment IMG_3662.MOV

Clearly I’m missing something here. Which is why I knew I wanted to share with you all before I actually tried to start building it, because I knew I would run into a problem and need some help.

Any geometry experts or engineers out there? Lol.

For now, I’m setting this to the side and will get the rest of this rack finished up. I still have a front bull bar to build too.

Andy

 

[ktmoutfront]

The actuator is too parallel to the plane between the rack pivot/top actuator hinge point. What would ne needed is a 2 arm, hinged in the middle scissor between the pumper and the rack. With the actuator pulling on the hinge point of the scissor bars.
If that makes sense.

 

[AugustDiesel]

The actuator is too parallel to the plane between the rack pivot/top actuator hinge point. What would ne needed is a 2 arm, hinged in the middle scissor between the pumper and the rack. With the actuator pulling on the hinge point of the scissor bars.
If that makes sense.

I thought about that, and wondered if some kind of cantilever would be needed.

I may need to choose a different point to attach to the rack then, because there’s barely room for any extension as is, certainly no room for a scissor arm or cantilever.

 

[AugustDiesel]

The actuator is too parallel to the plane between the rack pivot/top actuator hinge point. What would ne needed is a 2 arm, hinged in the middle scissor between the pumper and the rack. With the actuator pulling on the hinge point of the scissor bars.
If that makes sense.

Could be, depending on distance/length, that I already have a scissor/cantilever bar built in to my design. How about if I move the tabs at the wheel mount to the latch bar? Would require both ends of the latch bar being connected via hitch pins for easy disconnect to access the tire, but might work.



Andy

 

[ktmoutfront]

Lay it down. You need to start there and get some kind of non plane leverage. I did geometric math for a living, and I do not see an easy solution.

I would not trust the nut certs to hold that apparatus pulling it up. The sheet metal will peel open.

If you had a full rack, Ok then. Might as well mount an ATV winch in the roof rack to pull it up. Could be done cleanly.

 

[AugustDiesel]

Lay it down. You need to start there and get some kind of non plane leverage. I did geometric math for a living, and I do not see an easy solution.

I would not trust the nut certs to hold that apparatus pulling it up. The sheet metal will peel open.

If you had a full rack, Ok then. Might as well mount an ATV winch in the roof rack to pull it up. Could be done cleanly.

I’ll give this some more though while I finish up the rest of this.

 

[AugustDiesel]

Lay it down. You need to start there and get some kind of non plane leverage. I did geometric math for a living, and I do not see an easy solution.

I would not trust the nut certs to hold that apparatus pulling it up. The sheet metal will peel open.

If you had a full rack, Ok then. Might as well mount an ATV winch in the roof rack to pull it up. Could be done cleanly.

In the diagram above, the red line represents the latch bar, and the purple line represents the actuator, so it would still pull from the bumper, not the roof.

 

[AugustDiesel]

On a different note, I got my steering ram reattached to the tie rod finally. I originally had it welded to the tie rod, but that made it difficult to set the toe in. So I cut the welded mount off and put this one on from TMR customs. It’s an aluminum mount with biters to help hood it in place.



I don’t know how satisfied I am with the positioning of the ram. It gets awfully close to the differential (always has) and also still has a habit of rotating the tie rod. I’m contemplating flipping it, welding it to the axle tube right next to the diff, and mounting the tie rod end near the driver side knuckle.

 

[mrk5]

I have trouble with my ram rotating the tie rod too. About the best I've managed to minimize it is to cock the tie rod ends so they aren't in line with each other just a little off being straight up with the stud. I don't know if you can visualize that, it's a little hard to put into words.

The ideal scenario would be if the ram was more inline with the tie rod and mounted directly over or under it. But usually there isn't room for that. On yours, you could use longer tabs on the axle to push the ram out closer to the tie rod. That might help a little. Basically trying to get the ram parallel to the tie rod when looking down from the top. Although you do have to make some compromise because the tie rod moves closer to the axle when you turn.

On the actuator, you need to figure out a way to mount it so it's more inline with the direction you want the carrier to move rather than being inline with the carrier itself. As Wade was mentioning, one way to do that is to use something in between the actuator and carrier that redirects the motion of the actuator.

 

[ktmoutfront]

In the diagram above, the red line represents the latch bar, and the purple line represents the actuator, so it would still pull from the bumper, not the roof.

I figured that is what you were getting at. Still pulling a to flat of a plane parallel to the tire carrier mounts. The base location of the actuator needs to be moved up. But no room to do that.

Another crazy idea, not that yours are crazy. Most of mine are. What if you attached it on the back, where the end of the ram of the actuator would land on the ground and use it as a jack to push the carrier up?

 

[mrk5]

That could potentially help with the down part too.

 

[ktmoutfront]

That could potentially help with the down part too.

I think gravity has that covered.

 

[mrk5]

200 pound tire, that could be a little exciting.

 

[AugustDiesel]

I have trouble with my ram rotating the tie rod too. About the best I've managed to minimize it is to cock the tie rod ends so they aren't in line with each other just a little off being straight up with the stud. I don't know if you can visualize that, it's a little hard to put into words.

The ideal scenario would be if the ram was more inline with the tie rod and mounted directly over or under it. But usually there isn't room for that. On yours, you could use longer tabs on the axle to push the ram out closer to the tie rod. That might help a little. Basically trying to get the ram parallel to the tie rod when looking down from the top. Although you do have to make some compromise because the tie rod moves closer to the axle when you turn.

On the actuator, you need to figure out a way to mount it so it's more inline with the direction you want the carrier to move rather than being inline with the carrier itself. As Wade was mentioning, one way to do that is to use something in between the actuator and carrier that redirects the motion of the actuator.

I figured that is what you were getting at. Still pulling a to flat of a plane parallel to the tire carrier mounts. The base location of the actuator needs to be moved up. But no room to do that.

Another crazy idea, not that yours are crazy. Most of mine are. What if you attached it on the back, where the end of the ram of the actuator would land on the ground and use it as a jack to push the carrier up?

Definitely good ideas and I’m giving it some thought for sure.

Where I’m at right now is focusing on getting the other stuff done while we all figure out the best way to mount this ram. Made good progress today. The 3-piece tire carrier rig is done. Got the roof bar finished and the latch bar built, and all associated tabs (there are 16) burned in. There’s lots of cleaning to do then paint, but, if the weather holds out tomorrow, I nay just whip myself up a bull bar for the front bumper right quick. (I say quick, but nothing is quick).



Actually, I still have to make the stand that will hold the rack up level when it is folded down.

Andy

 

[AugustDiesel]

Altogether



Andy

 

[mrk5]

Heck it's all ready for a tire. I think you like having the sturdier latch setup.

 

[AugustDiesel]

Heck it's all ready for a tire. I think you like having the sturdier latch setup.

Yep. I’m looking forward to it. I’m thinking in the morning I’ll go ahead and get the front bull bar done so all the fabrication is out of the way, then get it all cleaned up and painted.