Dolly project *question*

[antiadam]

So, I decided to jump on the dolly building bandwagon. However, I'm having some problems, and after searching through the thousands of already posted dolly threads to no avail, I've given up and decided to ask for help.

This is my basic setup:

http://img.photobucket.com/albums/v355/antiadam/dolly/1.jpg


The only things not pictured are the 2 3/4" metal conduit pipes I've been using for track. I'm using a 2'x3' particle board for the base, and I have 4 sets of wheels on each side, which are mounted on steel "L" angles running the length of the dolly.

The wheels I'm using were taken off of cheap (new) Wal-Mart rollerblades and are mounted on a bolt in the following fashion:

nut : washer : "L" bracket : washer : wheel : 2 washers : wheel : washer : nut

I have three pole mounting.. things that I'm using to keep the tripod in place and a hook in the center of the board from which a string attaches to the tripod to keep it from falling off.

Basically, it's not very smooth. The wheels spin nicely when they're not touching anything, but when it's on the track I get a lot of vibration and shaking. In general it seems much less smooth than similar dollies I've seen other dvxusers build.

So, if anyone has any ideas for improvements I could make, or things I could differently, I would appreciate it very, very much.


Cheers!

- Adam


More pictures:

http://img.photobucket.com/albums/v355/antiadam/dolly/2.jpg
http://img.photobucket.com/albums/v355/antiadam/dolly/3.jpg
http://img.photobucket.com/albums/v355/antiadam/dolly/4.jpg
http://img.photobucket.com/albums/v355/antiadam/dolly/5.jpg

[pmark23]

How thick is the metal bracket? Looks like it would easily flex, which would cause problems.

[antiadam]

How thick is the metal bracket? Looks like it would easily flex, which would cause problems.


They're 1/8" thick.

Also, although I've tried to be as exact with my placement as possible, and the holes are predrilled, everything doesn't seem to be lined up perfectly, because every wheel doesn't make contact with the rail at all times, especially with no weight on it.

Think getting a sturdier bracket that allows for more precise wheel placement would help a lot?

[RyanT]

My dolly is quite similar to yours except I moved my bracket over more onto the board and added another one on the edge. I would imagine that your wheels would flex upwards if any weight was put on the board. Another bracket would solve that problem (+ spacers to make sure the wheels don't hit the board). I kinda made the same mistake as you though, my wheels aren't very lined up either.

[Dennis Wood]

Take out the two middle wheel sets. Keep in mind that roller blade wheels are designed to support 200lb dudes taking off from the toe of one skate. You don't need 16. If you're not comfortable with that, then at least move the two inner wheel sets outboard so they are almost touching the outside wheel sets.

[Neil Rowe]

..i wouldnt remove any wheels from that kit. the MDF (im assuming thats what is is from the pictures) board youve used is not desigend for unsupported weight in any large amount, and will bend as those factory slotted steel rails will not support much weight without bending. rollerblade wheels are desigend for weight, but not pressing from the side. they are designed to handle pressure straight down or angled vertically up perpendicular to the axle. basically when you make a dolly like this the track wedges in between the wheels and the pressure pushes the wheels out and rests more on the bolt not bending than it does on the wheels themselves unless your riding a really thick pipe. at which point the wheels would be able to slip off easily.

the vibration comes from the pipe wedging up between the wheels and then being gripped by the rubbery wheels and not wanting to release.. so it releases, and then grips again.. like sliding down a firemans pole wearing rubber gloves. I would assume that on flat ground like a gymnasium floor it rolls perfectly smooth. the solution would be to 1. space the wheels closer together and ride a smaller track 2. rise a larger track 3. angle the wheels in at the track so that the up and outward pressure is exerted perpendicular to the wheels axles and they will not stick as they are doing now. of course solution #1 and #2 will both cause instabillity in the setup since the dolly will not be "locked" to the track as well and could potentially come off when moving.

hope this helps. ..if not you may want to look into solution 4. click on the image in my signature and buy a "flippin sweet" rowe cine dolly wheel kit. ;)

whatever you end up doing .. good luck and happy shooting!

[Dennis Wood]

Good points Neil. I was thinking the same thing when I designed (and later scrapped) an inline system.

Talc, or furniture polish may quiet your situation by reducing friction between wheel and track.

These pics (http://my.tbaytel.net/guskers/dolly.html) show my original inline and then move to a skater desing like Neil sells. Note that the inline wheels are supported on both sides. Personally, I'm not a fan of the the wheels outboard as you have them...for the same reasons Neil has addressed.

If add another rail each side, then flip the wheels inboard you could have them supported on both sides. You'll just need to either space the rails out a bit, or cut slots for the wheels. Either way, you'll likely always need talc or polish on the rails to keep things quiet.

[cheezweezl]

maybe try better wheels/bearings as well. i have built a few dolly's and i learned quickly on my first one that cheap skate wheels suck. they are usually slightly out of round and the bearings are bumpy compared to the nice stuff. try some replacement wheels from a sporting goods shop. they will probably cost you $30-$40 for a set of 8 with abec5 bearings but it will make a huge difference. also, why did you go the straight up and down route rather than the standard 45 degree setup? seems like with the wheels both pressing inward on the pipe, it sits better and you're less likely to jump the track... i have a dolly very similar to yours. about the same size and made of particle board. i have 8 of the aggressive inline wheels on it which are just smaller versions of the regular wheels. i run it on 2" abs pipe (black smoother pvc) and it is like glass. i even used it with a 200lb. jib on top and still glass smooth.

[antiadam]

Thanks for all the replies. I picked up 2 more angled brackets today planning to try RyanT's method, but it seems like just ditching this setup and using the typical 45 degree setup is what I should do.

Neil, maybe you'd like to just send me one of your kits to, you know, show me how it's supposed to look? ;)

[PaPa]

i get tons of jitter with my skater dolly, but i blame the fact that as of right now im only using 8 wheels, and my dolly is too light duty for whta im doing. Optex 465.

it vibrates and sways as the dolly moves, which doesnt help at all, but im getting footage im pleased with