Designing The Penultimate Pulk Sled
The Penultimate Pulk Sled is the culmination of 2 seasons of trial and error (mostly error). I am indebted to all the brave souls who tried and erred before me. You can find most of them if you search for "pulk sled" on Google or YouTube. And if you're tempted to use parallel poles, watch this first.
My first attempt used PVC pipe with metal clips on each end, eye bolts, and a weight belt with bolts sticking out to attach the clips. It slid out of control on side hills, rolled over, twisted the PVC like spaghetti, broke metal pieces, and was a lot of fun! In fact, I used that sled on a 2 day camping trip to the rim of Crater Lake where I snapped the background picture for this blog AND a metal pole clip.
The brainstorm for the Penultimate Pulk Sled was the idea to use 2 pairs of grommets on the sled with a strap to keep the poles held tightly against the grommets. I was amazed at how well it worked, and how easy it was to build.
I was committed to using the grommet idea for the belt too. I discovered that if you make the rope loops on the end of the pole a little shorter than the distance between the 2 grommets on the belt, it holds the poles tightly to the belt, as shown in the video. I threw away several belts with more than 2 grommets in the center position that didn't work. You need to thread both pole rope loops through the same 2 center grommets to get them to stick against the belt. I used smaller rope on the belt end of the poles so 2 loops would go through 1 grommet. After trying 10 or 15 bad ideas, I also added a small cable tie on the rope loops to help thread them through the grommets.
12 comments:
How do you attach your cording to the lower end of your poles?
I cut a 3" piece of 1/2" schedule 80 PVC pipe. Then I drill a hole 1/2" from the end, a little bigger than the 4mm rope. 1" from the other end, I drill a clearance hole through once side of the pipe for a #8 flat head sheet metal screw and countersink it. You need to round up the inside edge of the rope end of the pipe with sandpaper so it doesn't cut the rope.
Then drill a guide hole for the #8 screw 1" from the end of the pole. I rough up the inside of the pipe a little with a drill, and the pole with a file. Then put the glue on it, put the pipe in place, put in the screw, and smooth out the glue.
The other end of the pole is the same, but drill a smaller hole for 3mm rope that attaches to the belt.
Hi,
Is the 1/2" measurement for the schedule 80 PVC pipe, for Outside diameter (OD), or is it 1/2" for inside diameter(ID)? I'm guessing its 1/2" of I.D. right?
http://www.harvel.com/pipepvc-sch40-80-dim.asp
This is a link to the PVC pipe diameters. 1/2" is the "nominal" size. The inside diameter of Schedule 80 is 0.526 inch, while schedule 40 is 0.602 inch.
any tips on the measurements for the grommets on the belt? i see three pairs, is the spacing critical?
Cut the 2" seat belt webbing to 5 feet long and singe the cut edges with a lighter. Then, fold it over to find the center. The grommets are placed 1 inch, 7 inches and 9 inches from the center in both directions. The grommet pairs need to be 2 inches apart to work.
I drilled guide holes in a 1 X 2 piece of wood and clamped the belt in place between it and a 2 x 4 base. I used the punch from a plain #2 grommet kit as a drill bit for the belt, sharpening it with a conical grinder. You have to take it out of the drill and push a pencil through it to clear it each time.
The 3mm rope loop on the belt end of the pole should stick out 1.5 inches past the edge of the PVC pipe. This is critical so tension on the belt will pull the poles tight against the grommets.
The 4mm rope loop on the sled end of the pole should extend 6" past the pipe edge. The grommets on the sled are 2" apart too, so this leaves enough room to get the tightening belt through then rope loop after it's threaded through the grommets on the sled, as shown in the video.
I'd like to use the penultimate design with a Jet Sled Jr. which has a different lip arrangement than the Paris sled or the Beast. The Jet Sled comes with pre-drilled drilled towing holes, but they are about 2.5" in from the sides rather than right at the corners, and about 1.75" below the lip.
1)Can you foresee a problem with attaching the poles to the body of the sled rather than the lip?
2)Do you think it would affect sled handling adveresely to use those holes since they are not on the corners?
3)How important is it to use spur grommets rather than regular grommets?
Thanks in advance. Gary
I'm still curious about a few details. Please advise on the following:
What are the dimensions/specs of the fiberglass poles?
Where did you purchase them?
What type of glue did you use for the plastic pipe?
Thanks!
Dave
I am having trouble putting the grommets in the sled. Maybe the wrong ones?
This is a great harness and the price is right.
https://www.midwayusa.com/product/878729/military-surplus-belgian-harness-grade-1-flecktarn-camo
Build and used this design on a 4 day cross park ski trip in Baxter State, Me. Put it through some punishing situations and worked perfectly. It’s an inexpensive yet reliable set up. Used my carpentry tool belt and shoulder harness as pulling connections.
Just remember to put something on the intersection point of the poles to minimize the sled overturning.
Thanks for the design ideas.
Question, why it use the existing holes/grommets on the front is the sled and the holes behind those rather than making new ones? I’m trying to figure out if I can attach my poles to the existing holes on the sled.
Post a Comment