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-   -   Dolly ready.. or is it.. (https://www.dvinfo.net/forum/dolly-track-cable/12253-dolly-ready.html)

Kevin Nardelle July 20th, 2003 12:55 PM

Dolly ready.. or is it..
 
I got a wild hair and put together a dolly for my boom.. I figured I could use rubber tires (air filled) for the dolly since it would be so heavy. I figured that 6 foot by 4 foot is big enough and heavy enough to be stable. I constructed this thing with ease..

1 20 foot piece of rectangle steel tubing 2"X1" at 1/8th" thickness(heavy wall) It is really cut to two 6 foot lengths and then two 3 foot 10 inch pieces for the cross members for the fore and aft pieces. SO what I have is a rectangle frame welded together using a wirefeed welder. I ran a cross hatch of 1 inch steel box tubing inside the frame for support and covered that with 1/4" thick Aluminum Diamond Plate that I neatly cut to fit inside the frame and on top of the cross hatch. I ran bolts through the aluminum and steel supports to fasten it down (solid as a rock!)

For the wheels and axles I decided to use 5/8 heavy grade bolts that i welded to the side fo the frame and towed them in properly. I then bolted the wheels onto each bolt witha nylon lock nut. The thing looks bad ass but I am wondering if this is going to work at this point. The wheels can be filled to 80 pounds and that makes them rock hard, they can also run under pressure for a cushion ride. Either way I think I am in trouble.. The wheels need to be replaced with smooth tires, they have knobies on them and they give that brrrrr kinda bump when it rolls.. A high frequency brrrrr.. lol.. If I replace them with smooth rubber wheels I still have the problem of only being able to operate this monster on smooth ground only. I toyed with the idea of using the wheel bolts to attach another piece of frame tubing with a row of 12 skateboard wheels in the front and 12 in the back on each side. Now I need track - that is a HUGE issue. Where or what am I going to use for the track?

Ideas welcome..

Mike Rehmus July 20th, 2003 08:49 PM

Ribbed Wheelbarrow tires are my choice. Run them soft and you can operate over some small obstacles with few problems. But you've just discovered why most dolly systems run on tracks.

Kevin Nardelle July 20th, 2003 09:18 PM

dreaded tracks
 
I shutter to think of how I am going to find the material to make the track and make it sectional with NO (ZERO) seams. Bumpless track is hard to manufacture - remember a skateboard wheel is hard and will transmit any tiny bump through the entire platform all the way to the camera.

ideas? THANKS! I appreciate the feedback and the time you take to read and post.


I have pics of my finished products, i need to post Maybe I can get them up tonight.

Cosmin Rotaru July 21st, 2003 04:48 AM

I've seen soft skateboard wheels. I didn't bought any yet. I wonder if they could hold the weight if placed in "V"...

Andrew Petrie July 21st, 2003 07:50 AM

Cosmin, there was talk of a DIY track dolly system that used PCV tubing, and skateboard wheels in the V you suggest last year. I forget the direct link, but it was strong enough and worked quite well.

Kevin Nardelle July 21st, 2003 12:43 PM

exactly
 
My wheels will be mounted in a V pattern, what else would it be.. Thats the only way to remain on track and reliable. Soft wheels - I dont know about that but I do know that PVC would crush under the weight of my crane and dolly without me, with me on it - forget it. I need steel tubing or aluminum rail like the one I saw on the movie set here:)

Mike Rehmus July 21st, 2003 09:32 PM

The problem with mounting the skate wheels in a V is that the bearings are not designed to accept a sideways thrust and will quickly destroy themselves, depending on the weight you place on them. Probably 10 pounds of camera and support wouldn't hurt them but heavy loads certainly will.

If you look, you may be able to buy some tubing or doweling that will fit inside the Schedule 40 piping and give you the seamless connection you need.

Don't forget to get some wooden wedges so you can level the track.

Kevin Nardelle July 21st, 2003 10:18 PM

wood
 
I was planing on making my wedges from acetron, much more durable and long lasting.. the problem is that PVC will not hold up, I am dealing with almost 400 pounds as it is when all is said and done with crane, dolly me, equipment, and batteries. no PVC pipe will stand up to that kind of weight and abuse even if the weight is spread over a foot area.

Mike Rehmus July 22nd, 2003 10:08 AM

Sched 40 or 80 will probably do so. Remember the 400 pounds is distributed over at least 8 contact points and those running on the same tube are several feet apart.

Wedges are so disposable that I'd buy them, not make them. Remember you may want a LOT of them to level out a particulary uneven bit of ground. You will also want some pads for soft ground so the wedges won't just sink in.

Kevin Nardelle July 22nd, 2003 11:02 AM

save a penny
 
I have the material.. I would rather save every penny i can right now.. I understand what you are saying though.

Robert Poulton July 22nd, 2003 08:18 PM

I went to Fred Meyers last week and got a heavy duty gardening wagon. It has the industrial plastic for the wagon part then nice air filled wheels and a sturdy frame. They say it can hold up to 800lbs. I don't really want to push it that much. I know it can hold well over 400lbs. Smooth enough ride but still some bumps. I think I need to deflate the tires just a little.

Rob:D

Kevin Nardelle July 22nd, 2003 08:25 PM

??
 
what are you trying to say? I have a HUGE platform, it is not a garden thing, my probmen is finding the right track material.. PVC is just not going to hold up, it is WAY TOO flexible, get humps like rolling hills. I might stick with the new smooth tires and abandon the track till I can get some aluminum rails.

John Threat July 23rd, 2003 05:57 AM

Actually, there are different sizes of PVC pipe. Some of the thicker widths can easily hold 400 pounds or more without crushing. Set your skateboard wheels on brackets that can accomodate those.

Prehaps use the 3 wheel setup with one wheel one top and two on either size of the pipe.

The flexiblibility is actually good because you have a better chance of using a curved section of pvc pipe, than finding a nicely curved aluminum or steel pipe at an arc big enough to allow the dolly to turn on it.

John Threat July 23rd, 2003 06:00 AM

That being said, you can use a doorway dolly in a lot of places, and you could always use cheap 3 ply wood sheets to make a flat area that the doorway dolly can run on outside in the open.

Mike Rehmus July 23rd, 2003 10:29 AM

I quickly found that plywood sheets as an operating surface are not too good. They have to be leveled just like track and they are so large that they droop. Then pebbles and other junk get on them so one is always sweeping them. Did I mention they are heavy and clumsy.

Schedule 40 or 80 PVC plastic will carry a very heavy load without noticably distorting. Cheap, easy to cut and bend, easy to join.

And you can always use it for sprinkler pipe when your shooting days are over.


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