Pylon Swivel Tracking Camera Mount

(Designed By Dave Benson)

Overview

This page documents the parts and assembly of an easy to make video camera mounting device that allows a video camera to be mounted on the tow pylon of a ski boat and track the movement of the skier using the movement of the rope.
Note that each photo is a link to the large high res image which should give you a pretty good idea of what this looks like. A comparable desing from Trakker is about $250. The design was triggered by someone on the Moomba board that mentioned a PVC design, but no specifics. I came up with this design while standing in the p[lumbing section of Menards. Took about 20 minutes to design in my head and find the parts, kine fo a 'This looks like it might work ... ' process.

Design notes: I actually found it helpful to have the hole in the cap for the pivot to be slightly off center. Eventually when I added the axel stabilizer the lack of precision in the location of the holes in the cap and stabilizer worked to my advantage in making the vertical angle of the tracking arm variable by simpley turning the top cap (which is not glued). This was a fluke but worked to my advantage.

ACTUAL FOOTAGE - Click Here - shot with an old Hi-8 video camera on tape, caputred in Pinnacle Studio using Dazzle, and converted to a Fair Windows Media File (wmv). This is me, third day of skiing in 2011 (June 5) at 15 off @ 34 mph, with 5 adults in the boat. Lots of room for improvement.

Images

Following these images is a parts list and some basic assembly instructions. DOUBLE CLICK ON A PHOTO for very large image. Single Click for typical image.

Assembly photos

Photo 1

Photo 2

Photo 3: All parts

Photo 4: Note the notches in the top to receive the axel stabilizer.

Photo 5: The pivot is from a video converter system. Basically a sholder bolt that screws into the bottom of the camera.
The black 'top hat' is part of that assembly and works great as a the connection between the pivot, the clamp
and the threaded rod. The duct tape around the shoulder allow for sligthly oversized hole in cap.

Photo 6: Underside of cap, shwoing axel stabilizer (door shim). The stabilizer acts as the second mount point for the
pivot to keep it from tiping. The stabilizer fits in the notches in the sleeve shown above.

Following these images is a parts list and some basic assembly instructions. DOUBLE CLICK ON A PHOTO for very large image. Single Click for typical image.

Assembly photos
Photo 1	Photo 2
Photo 3: All parts	Photo 4: Note the notches in the top to receive the axel stabilizer.
Photo 5: The pivot is from a video converter system. Basically a sholder bolt that screws into the bottom of the camera. The black 'top hat' is part of that assembly and works great as a the connection between the pivot, the clamp and the threaded rod. The duct tape around the shoulder allow for sligthly oversized hole in cap.	Photo 6: Underside of cap, shwoing axel stabilizer (door shim). The stabilizer acts as the second mount point for the pivot to keep it from tiping. The stabilizer fits in the notches in the sleeve shown above.

Parts List

The critical piece that I happened to already have was a tripod mount device from 8mm to video converter kit. It was basically a threaded shoulder bolt that screws into the bottom of the camera, plus it has a upside-down tophat threaded on the end. This is the attachment point to the camera plus provide the swivel function. It could be a standard shoulder bolt with a few large washers or something clever like that.

In addition to the pivot mentioned above and the parts listed below I use:

1 wooden door shim - cut to fit inside cap, ust the fat end, and notch the sleeve to accept it - with a little slop.

2" duct tape - wrapped around the pivot to compensate for overdrilling the hole for the pivot. - Consider this a home made bushing.

6" string - Safety device to hold the rope clip to the control arm in case it come out.

Krazy glue - did not have Loctite - to keep the clamps from spinning on the threaded rod.

All otehr parts are from Menards (not sure if SKU is universal?).

Qty SKU $/pc Description
1 ? 3" ID x 16" PVC pipe, I had a piece laying around so used that, ASTM F81-93
http://www.menards.com/main/plumbing...259-c-8571.htm

1 6891983 3.63 3" PVC cap
http://www.menards.com/main/plumbing...340-c-9384.htm

2 6790623 0.78 2 3/4 hose clamp, combine with 1 3/4 clamp to make one 4.5 inch clamp
http://www.menards.com/main/plumbing...241-c-9422.htm

2 6790616 0.78 1 3/4 hose clamp - combine with 2 3/4 clamp to make one 4.5 inch clamp
http://www.menards.com/main/plumbing...241-c-9422.htm

2 6934471 1.45 1" split ring hanger, 3/8 female thread on one side. This one appears to be copper, but mine was powder coated.
http://www.menards.com/main/plumbing...613-c-9424.htm

1 2289254 1.78 3/8 x 16" threaded rod - cut down to 7 inches.
Similar to this, but available in shorter lengths
http://www.menards.com/main/p-1628619-c-9538.htm

1 6874214 1.99 12-19" SliderTM Adjustable Support Bracket - only used the female half cut down to about 3.75 inches with the spike end flattened to make a 90 degree spike,
http://www.menards.com/main/plumbing.../p-1340619.htm

12 6932542 1.49 1/2 x 6 " Copper Pipe Hanger - only used 1 but they came in packs of 6, cut off the bent ends so the legs are straight.
http://www.menards.com/main/plumbing...592-c-9424.htm

1 na ? 3/16 x 4 x 12 hard rubber pad. I used remnants of an old Connelly Super Wrap front boot, so no cost there. You might be able to use something like this:
http://www.menards.com/main/plumbing...863-c-8578.htm

Assembly

Assmbly Instructions
Part Item(s) Instructions

Sleeve
1 - 3" x 16" PVC pipe
2 - 2.75+1.75 hose clamps
1 - 3/16 x 4 x 12 hard rubber pad

1. Sleeve Clamps: do this twice: connect the 2.75 and 1.75 clamps to make a single clamp that will fit nicely around the pvc pipe. A single clamp will work if it is big enough, but I was trying to avoid a lot of loose clamp sticking out to catch on legs.

Be careful with the next steps. Make sure you know how to use whatever tools you choose. Wear eye protection.
I used a Radial Arm saw for all cuts on the PVC sleeve. But a router or Dremel or otehr tool may work.
See Photo 4 above

2. Rope slot: Cut a slot in the PVC sleeve about 12.5 inches long and 1 inch wide from the bottom of the sleeve. This slot serfver tow purposes. First it allows intall/remove without taking off the rope. Second, it allows the hose clamps to compress the sleeve to tighten it aroudn the pylon.

3. Rope clearance: This is at the top of the slot and is where the rope will be coming out of the sleeve at the connection point to the pylon.
This clearance gap is about 3.5 inches wide and 1.5 inches high. The idea is to not interfere with the movement of the rope. If you are pulling guys at 41 off you may want to make it a little wider.

4. Axel Stabilizer seat: Because the cap fits tight on top of the sleeve you need to provide a seat (Photo 4 - top of sleeve) for the shim (Photo 6, inside cap).
The seats are slightly wider than the shim and on a diameter of the sleeve.
Using a standard door shiim the seats are about 1.75" wide and 3/16 deep. Top of the shim should be at the same level as the top of the sleeve (or lower).

5. The hard rubber is an insert that goes between the pylon and the sleeve. This prevent dangerous over-deflection of the PVC. Even with the rubber the PVC will almost completely close the 1 inch gap - depending of cource on hoe much rubber you use. The Connelly binding material I used went around the pylon about 1.5 times. I think it also helps deaden vibration a little. IT is not permamently installed, just slip it in during installation.

Cap 1 - 3" PVC cap
1 - door shim (axel stabilizer)
1. Drill a hole slightly off center in the top of the cap and slightly larger than the pivot you will be using. If you are going to use bushings plan acordingly. I used duct tape (friction tape did not work) tightly wrapped (see Photo 5)

2. Cut the fat en of the door shim to length so that it fits snugly inside the cap without splitting. Transfer the hole from teh cap to the shim with a pen. Drill the hole so it is a snug fit to your pivot.

Clip
1 - 1/2 x 6 Copper Pipe hanger
1- 6" string

This is the device the rope will pass though. This is basically just a thick copper clad steel wire pre-bent in the shape of a U that has a little bit of spring tension in it.

1. Cut off the bent spikes so that the clip legs are straight. Ref top right of Photo 3.

2. Tie the stringto the clip securly at the bottom of the U shape (you may need more than 6" to start with)

Clip Retainer 1 - 12-19" SliderTM Adjustable Support Bracket
This hanger was chosen for two specific reasons:
A. the shape fits nicely in the pipe clamps and naturally resists turning.
B. The curled edges of the femal half could be easily adapted to hold the clip.

1. Remove the 'male' part of the slider so all that you are using is the part with the curled edges (female part).

2. Cut the female part of the slider (keeping the finished wnd with the nailing spike) to about 3.75 inches

3. Bend the nailing spike to that it is flattened and 90 degrees to the slider. See Photo 2

4. Be Careful with this - Use a scredriver or other implement to expand the curled edges (sliding channels) of the female bracket from the open end up about 2.5 inches. The sliding channels will become the new home for the Clip. The channels should be expanded enough to enclose the clip legs, but still allow the clip to be removed and reinserted. See Photo 5

Tracking Arm 1 - 3/8 threaded rod
2 - 1" split ring hanger
1 - Krazy Glue
1 - Clip Retainer (from above)
This can make or break the whole design. The goal is to keep the split ring hangers from rotating under the pressure of the rope. I used Krazy glue, but any other form of thread locking would probably work, mashing the threads, Loc-tite, double-nutting, etc...

1. Cut the threaded rod to about 7 inches. Try to make sure that you have good threads from at least one side of the rod because you will be threading the ends into the hangers. I actually threaded the hangers on further than they would go and then cut the thread so I could then thread them back out to the ends. I used a Recip saw but there are more elegant ways to cut threaded rod.

2. Tighten the side screws on one hanger and thread the rod about 70% into the hanger.

3. Place the Clip Retainer into the hanger on the opposite side form the rod connection, so that the bent nailing spike is is pointing in (toward rod connection) and flush to the top of the clamp. See Photo 5

4. Screw the threaded rod into the hanger until it is tight against the Clip Retainer.

5. Back out the threaded rod 5 or 6 turns, apply thread sealant (Krazy Glue), and thread the rod back into the hanger until it is secure against the Clip Retainer.

6. Let thread sealant cure.

7. Insert remaing end of rod into remaining split ring hanger, leaving enough clearance for the 'top hat' of the pivot. Photo 5. Wait on sealing these threads until you have the pivot assembly in place. I actually do not have any on current design because the tophat is plastic and I am using teh 'cut' end of the threaded rod in this hanger so when I tighten it into the tophat it sort of locks itself.

Final Assembly
IMPORTANT: Remmeber that the pivot and the Clip retainer must both extend below the threaded rod. Photo 5 and be parallel.

1. Put your pivot in the open split ring hanger and tighten the threaded rod. (you can add thread sealant noe if you like, but might want to wait)

2. Slip the Clip into the channels on of the Clip retainer.

3. Tie the string from the Clip to the Hanger for the Clip Retainer - make sure the clip can be removed without untiing the rope.

4. Insert the pivot into the Cap

5. Place the Axel Retainer (shim) on the inside of the cap - over the pivot axel.

6. Turn the sleeve upside down and slip the cap assembly on the end of the sleeve aligning the Axel Reatainer seats with the Axel Retainer.

Installation
To actaully install on the pylon:

1. Remove the rope (quick release clmaps would make it possible to not need to remove the rope)

2. Remove the hose clamps from the sleeve and slide them over the pylon

3. Reattach the rope to the pylon

4. Remove the Hard Rubber from the insdie of the sleeve

5. Slide the Sleeve over the pylon using the slot to allow for the rope.

6. Wrap the hard rubber sheet around teh puylon and sliip it up into the Sleeve (now on the pylon)

7. Slip the Hose clamps up onto the sleeve spaced about 4 inches from teh bottom and between each other. Secure clamps

8. Point Traking Arm to rear of boat.

9. Place rope in Clip and slide clip into place in Clip Retainer.

10. You may find that you can fin-tune the vertical angle of the arm by rotating the cap in either direction.

11. Secure the camera to the pivot mount. Make sure any straps or cables are secure and will not fly up in front of the lense when filming.

Go skiing You can shorten the rope by removing the Cap assembly , but ther eis not a lot of clearance in the curren tdesign. Future improvements are needed for this functionality to be optimal.

Part	Item(s)	Instructions
Sleeve	1 - 3" x 16" PVC pipe 2 - 2.75+1.75 hose clamps 1 - 3/16 x 4 x 12 hard rubber pad	1. Sleeve Clamps: do this twice: connect the 2.75 and 1.75 clamps to make a single clamp that will fit nicely around the pvc pipe. A single clamp will work if it is big enough, but I was trying to avoid a lot of loose clamp sticking out to catch on legs. Be careful with the next steps. Make sure you know how to use whatever tools you choose. Wear eye protection. I used a Radial Arm saw for all cuts on the PVC sleeve. But a router or Dremel or otehr tool may work. See Photo 4 above 2. Rope slot: Cut a slot in the PVC sleeve about 12.5 inches long and 1 inch wide from the bottom of the sleeve. This slot serfver tow purposes. First it allows intall/remove without taking off the rope. Second, it allows the hose clamps to compress the sleeve to tighten it aroudn the pylon. 3. Rope clearance: This is at the top of the slot and is where the rope will be coming out of the sleeve at the connection point to the pylon. This clearance gap is about 3.5 inches wide and 1.5 inches high. The idea is to not interfere with the movement of the rope. If you are pulling guys at 41 off you may want to make it a little wider. 4. Axel Stabilizer seat: Because the cap fits tight on top of the sleeve you need to provide a seat (Photo 4 - top of sleeve) for the shim (Photo 6, inside cap). The seats are slightly wider than the shim and on a diameter of the sleeve. Using a standard door shiim the seats are about 1.75" wide and 3/16 deep. Top of the shim should be at the same level as the top of the sleeve (or lower). 5. The hard rubber is an insert that goes between the pylon and the sleeve. This prevent dangerous over-deflection of the PVC. Even with the rubber the PVC will almost completely close the 1 inch gap - depending of cource on hoe much rubber you use. The Connelly binding material I used went around the pylon about 1.5 times. I think it also helps deaden vibration a little. IT is not permamently installed, just slip it in during installation.
Cap	1 - 3" PVC cap 1 - door shim (axel stabilizer)	1. Drill a hole slightly off center in the top of the cap and slightly larger than the pivot you will be using. If you are going to use bushings plan acordingly. I used duct tape (friction tape did not work) tightly wrapped (see Photo 5) 2. Cut the fat en of the door shim to length so that it fits snugly inside the cap without splitting. Transfer the hole from teh cap to the shim with a pen. Drill the hole so it is a snug fit to your pivot.
Clip	1 - 1/2 x 6 Copper Pipe hanger 1- 6" string	This is the device the rope will pass though. This is basically just a thick copper clad steel wire pre-bent in the shape of a U that has a little bit of spring tension in it. 1. Cut off the bent spikes so that the clip legs are straight. Ref top right of Photo 3. 2. Tie the stringto the clip securly at the bottom of the U shape (you may need more than 6" to start with)
Clip Retainer	1 - 12-19" SliderTM Adjustable Support Bracket	This hanger was chosen for two specific reasons: A. the shape fits nicely in the pipe clamps and naturally resists turning. B. The curled edges of the femal half could be easily adapted to hold the clip. 1. Remove the 'male' part of the slider so all that you are using is the part with the curled edges (female part). 2. Cut the female part of the slider (keeping the finished wnd with the nailing spike) to about 3.75 inches 3. Bend the nailing spike to that it is flattened and 90 degrees to the slider. See Photo 2 4. Be Careful with this - Use a scredriver or other implement to expand the curled edges (sliding channels) of the female bracket from the open end up about 2.5 inches. The sliding channels will become the new home for the Clip. The channels should be expanded enough to enclose the clip legs, but still allow the clip to be removed and reinserted. See Photo 5
Tracking Arm	1 - 3/8 threaded rod 2 - 1" split ring hanger 1 - Krazy Glue 1 - Clip Retainer (from above)	This can make or break the whole design. The goal is to keep the split ring hangers from rotating under the pressure of the rope. I used Krazy glue, but any other form of thread locking would probably work, mashing the threads, Loc-tite, double-nutting, etc... 1. Cut the threaded rod to about 7 inches. Try to make sure that you have good threads from at least one side of the rod because you will be threading the ends into the hangers. I actually threaded the hangers on further than they would go and then cut the thread so I could then thread them back out to the ends. I used a Recip saw but there are more elegant ways to cut threaded rod. 2. Tighten the side screws on one hanger and thread the rod about 70% into the hanger. 3. Place the Clip Retainer into the hanger on the opposite side form the rod connection, so that the bent nailing spike is is pointing in (toward rod connection) and flush to the top of the clamp. See Photo 5 4. Screw the threaded rod into the hanger until it is tight against the Clip Retainer. 5. Back out the threaded rod 5 or 6 turns, apply thread sealant (Krazy Glue), and thread the rod back into the hanger until it is secure against the Clip Retainer. 6. Let thread sealant cure. 7. Insert remaing end of rod into remaining split ring hanger, leaving enough clearance for the 'top hat' of the pivot. Photo 5. Wait on sealing these threads until you have the pivot assembly in place. I actually do not have any on current design because the tophat is plastic and I am using teh 'cut' end of the threaded rod in this hanger so when I tighten it into the tophat it sort of locks itself.
Final Assembly		IMPORTANT: Remmeber that the pivot and the Clip retainer must both extend below the threaded rod. Photo 5 and be parallel. 1. Put your pivot in the open split ring hanger and tighten the threaded rod. (you can add thread sealant noe if you like, but might want to wait) 2. Slip the Clip into the channels on of the Clip retainer. 3. Tie the string from the Clip to the Hanger for the Clip Retainer - make sure the clip can be removed without untiing the rope. 4. Insert the pivot into the Cap 5. Place the Axel Retainer (shim) on the inside of the cap - over the pivot axel. 6. Turn the sleeve upside down and slip the cap assembly on the end of the sleeve aligning the Axel Reatainer seats with the Axel Retainer.
Installation		To actaully install on the pylon: 1. Remove the rope (quick release clmaps would make it possible to not need to remove the rope) 2. Remove the hose clamps from the sleeve and slide them over the pylon 3. Reattach the rope to the pylon 4. Remove the Hard Rubber from the insdie of the sleeve 5. Slide the Sleeve over the pylon using the slot to allow for the rope. 6. Wrap the hard rubber sheet around teh puylon and sliip it up into the Sleeve (now on the pylon) 7. Slip the Hose clamps up onto the sleeve spaced about 4 inches from teh bottom and between each other. Secure clamps 8. Point Traking Arm to rear of boat. 9. Place rope in Clip and slide clip into place in Clip Retainer. 10. You may find that you can fin-tune the vertical angle of the arm by rotating the cap in either direction. 11. Secure the camera to the pivot mount. Make sure any straps or cables are secure and will not fly up in front of the lense when filming.
Go skiing		You can shorten the rope by removing the Cap assembly , but ther eis not a lot of clearance in the curren tdesign. Future improvements are needed for this functionality to be optimal.