Jump to content

Mounting A Lenny Arm Onto A Truck


Ken Keeler

Recommended Posts

Hey everyone,

 

Within the next week I will be shooting a Western. In the film there is a chase scene on horses, we will be shooting on the RED with Lomo Anamorphics, we have rented a Lenny Arm with a high post kit, a Vibration Isolator, and a remote head. Here is what I am trying to accomplish, we have multiple shots following the lawmen on the horses.My plan is to rig the either 6ft or 8ft Lenny Arm into the back of a pick up truck the lenny arm will then have the Vibration Isolator mounted following with the remote head.

OPTION 1. My first idea was to build a speed-rail rig secured to the bed of the truck which then had a Mitchell mount / or a Mitchell cheese plate bolted into this little grid.

OPTION 2. I had a remote head tech suggest I take a bazooka mount which i have access to and bold it straight into the bed of the truck.

 

To give you more information our terrain is desert/sand there are dirt roads but they are not the smoothest.

 

Please any ideas will help thanks for your time I look forward to your response!

 

Ken

Link to comment
Share on other sites

Truck beds are sheet metal and not nearly as stiff as Ford, GM, etc. would want you to think. Anything you bolt down will have to be tied directly to the frame rails or crossovers for stiffness. It probably will require the construction of a subframe, bolted into the bed first. Seems like a "camera car" would already so modified.

Link to comment
Share on other sites

Hey everyone,

 

Within the next week I will be shooting a Western. In the film there is a chase scene on horses, we will be shooting on the RED with Lomo Anamorphics, we have rented a Lenny Arm with a high post kit, a Vibration Isolator, and a remote head. Here is what I am trying to accomplish, we have multiple shots following the lawmen on the horses.My plan is to rig the either 6ft or 8ft Lenny Arm into the back of a pick up truck the lenny arm will then have the Vibration Isolator mounted following with the remote head.

OPTION 1. My first idea was to build a speed-rail rig secured to the bed of the truck which then had a Mitchell mount / or a Mitchell cheese plate bolted into this little grid.

OPTION 2. I had a remote head tech suggest I take a bazooka mount which i have access to and bold it straight into the bed of the truck.

 

To give you more information our terrain is desert/sand there are dirt roads but they are not the smoothest.

 

Please any ideas will help thanks for your time I look forward to your response!

 

Ken

 

You have couple of options, the "easist" is to mount the dolly in the back of the pick up. do a 4 point lock down with 1000lb or 2000lb rat straps going to 4 points and having the arm come off the dolly. However to do this you will want a full size pickup with rear dualiaes to help keep the ride stable. You have to pick you points carefully to make sure the rat straps dont bend or damage where ever yuo tie off too.

 

You also could you sticks as your mount point, but the dolly will be stable.

 

One other idea is to use steel pipe to span the pick up bed side to side, and have a mitchel mount in the middle and mount the arm to that. Again you have to be careful where you attach the rat straps. And make sure you can brace the arm/mount in at least 4 points.

Link to comment
Share on other sites

  • Premium Member

Anything you bolt down will have to be tied directly to the frame rails or crossovers for stiffness.

 

Yup. Take a look at those 5th wheel setups for towing heavy trailers. The guy I bought my F-350 from had one on it, which he transferred to his new truck. That'll give you a good idea where and how to bolt things....

 

 

 

 

-- J.S.

Link to comment
Share on other sites

Apart from securing the arm to the vehicle, you'll have enormous shake problems if you aren't using a stabilized remote head (Wescam, Libra, Flight Head, etc.), especially at anything approaching the speed of horses galloping. You may want to move the action to a location where the tracking vehicle is on a road and the horses & background are off-road.

 

Also, horses will be very skittish with a crane arm swinging in front of their faces. Are the riders and horses familiar with working with cameras? Are the riders stunt people or "just" actors? Is your grip experienced with operating an arm in a moving vehicle? The physics of that are interesting, to put it gently. Is there enough room in the bed of the truck to operate the arm? Where are the remote head op, the director, the DP, the AC, sound, and the other essential crew going to sit / ride? Will the driver of the tracking vehicle be a stunt driver, or at least have experience doing this sort of thing?

Link to comment
Share on other sites

Wicks points are really really important. Especially the part about what happens to the arm and the grip operating it. The fact that as DP of the movie, you are posting this question here leads me to wonder how much experience your Key / Rigging grip has. These setups can quickly turn ugly without the experience necessary to preempt disaster. An experienced insert car driver is really important.

Now having assumed you have already got all of that under control, the most important thing to understand is the vast quantities of torque a crane arm thats being swung around will exert on its mounting points.

I would avoid mounting it on a proper dolly (Fisher 10 or Hybrid) simply because you risk damaging the dolly (wheel arms,king pin etc)with the amount of force the 2 tonne ratchet straps would exert.

 

Better would be a crane base of some kind.

 

Straps will work, but speedrail is not a bad solution either. The best way in my opinion would be to get long U-bolts around the tube (steel not alu) to the ladder frame of the truck chassis and then build from there.

 

More important than all of this would be to get a good grip and good driver both of whom have experience doing this.

 

Also the vibration isolator will not help without a stabilised head. What does work pretty well is Chapmans vertical vibration isolator, but then you cannot use the arm.

 

Good luck

 

Tell us how it goes.

 

Sanjay Sami

Edited by Sanjay Sami
Link to comment
Share on other sites

"I would avoid mounting it on a proper dolly (Fisher 10 or Hybrid) simply because you risk damaging the dolly (wheel arms,king pin etc)with the amount of force the 2 tonne ratchet straps would exert."

 

As long as you attach the rat straps to the lift points of the dolly you will be fine. I have talked to people at fisher before about the load ratings for there grab points. And I know Chapman well enough to say you should be fine, but if you have any questions you can call Chapman.

 

As for moving the arm around, you will not have much space in the bed of the pick up with either a jib base or a dolly. So you won’t get much in the way of movement. But if you are just using the arm to reach out and offset the camera to keep the trucks dust out of shot you should be ok. However you will still have the problem of how to safety your crew members in the bed to the truck.

 

But most importantly if you key grip does not feel 100% sure he can do this safely you should really look into a camera car that you can mount a crane into or a Russian arm for the shot. As those might seem pricey however they are quite cheap compared to the price of a lawsuit. Or even losing a day because you cant get the shot you need off the truck bed.

post-44532-12804208663222.jpg

Link to comment
Share on other sites

I'm going to take a wild guess and say with just a weeks notice for this shot, that production is thinking that they'll buy a junker pickup (better be 3/4 or 1 ton) to use for the shoot, trash it and write it off. If that's the case, your best bet might be removing the bed entirely and building a steel reinforced platform tied to the frame. You could have a 8x12' platform, proper tie down points. Off road, no need to worry about DOT regs. You might be able pull this off with the right fabricator, but it sounds more likely that someone will be making a trip to the hospital from a rollover or worse.

Link to comment
Share on other sites

First off thanks everyone so much for there responses you guys brought up great ideas and good concerns.

 

The shoot went very well and the day we did the truck rig was fun and interesting. for me as DP of course I wanted to get these amazing shots but my biggest worry was my crews safety.If it wasn't going to work i was going to scrap the whole idea. Just as a reminder we did not need the camera to jib up or down we just need the camera to be offset from the truck bed to eliminate the possibility of 1. either seeing the truck and 2. seeing all the dust coming from the truck. When i talked to my key grip about this idea a month or so before production he said he would work on some ideas and i would do the same and we would meet back up and go through the pro and cons of all the ideas safety, time, weight of the rig etc.

 

Any-who our final decision was to mount the Chapman Super PeeWee into the bed of the truck and then build the Lenny arm on the dolly to give us the offset. My key grip told me he was going to do a 4 point tie down on the highpost to the frame of the truck. once this was secure we gave it a good test and this thing was not moving. Granite there was still worry in my mind that the ratchet straps could break with all the stress and movement one we actually started rolling. we made the executive decision to no go above a speed of 10MPH. we never had anyone in the bed of the truck when we were rolling. and inside the cab we had the op with his monitor and the controls to the remote head. here are some photos to check out all this crazyness. i have learned that even though this worked and we had no problems i think is one of those situation where i wont do this again unless i have the right tools for the job.

38817_1318235526881_1560540135_704308_5341152_n.jpg

38676_1318235246874_1560540135_704303_2715954_n.jpg

Link to comment
Share on other sites

That looks like it worked pretty well . I don't think it was a dangerous as you thought . I've mounted various different arms in the back of pickups and other vehicles more times than I can remember . It's one of those scenarios that seems really dangerous the first time but if you make sure your load capacities are well well within the manufacture's spec then you shouldn't ever have a problem . As long as there aren't many big bumps causing large shock loads . Here is a pic of a rig I did on my rock crawler a few years ago . It's a gyro stabilized flight head mounted on the filmotechnic shock mount . It worked amazingly well (considering we drove through the waves on a beach completely submerging the head itself) Maybe we should start a thread about vehicle mounted rigs to see what other guys have done ?

post-47467-12810239944729.jpg

Link to comment
Share on other sites

  • Premium Member

... make sure your load capacities are well well within the manufacture's spec ...

 

Depending on the truck, you may also have to watch out that you don't under-load it. Mine needs about a ton in the back to ride nice. Empty, it's always at the top of the suspension travel, so it rides like it doesn't even have springs. Not really a big pain, but definitely in the tush.... ;-) You want to avoid hitting either the top or the bottom of your springs. Both ends make bumps.

 

Take the Gross Vehicle Weight Rating, subtract the weight of the truck empty. Divide by two. That's your target, the middle of the range. For example:

 

10,000 - 4,250 = 5750

 

5750/2 = 2875

 

 

 

 

-- J.S.

Link to comment
Share on other sites

Take the Gross Vehicle Weight Rating, subtract the weight of the truck empty. Divide by two. That's your target, the middle of the range. For example:

 

10,000 - 4,250 = 5750

 

5750/2 = 2875

 

 

 

 

-- J.S.

 

James I this thats a great idea! we should start a truck/ car rigging thread count me in :) and ya it doesnt seem as bad now. You are right if you take the necessary safety precautions and you have the right tools for the job then you can safely mount these fun toys. James how did you mount the speed rail on you jeep I was at Modern

Studio Equipment the other day and saw this awesome grip tool. it was a trailer hitch to pipe adapter looked very useful but the thing with it that you have to keep in mind is you can only put on a weight load that your hitch can handle 350_016_4035.jpg

 

J.S. that is a useful formula! thanks for that

 

 

Ken Keeler

Edited by Ken Keeler
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...