This is the World Famous TelemarkTalk / TelemarkTips / Telemark Francais Forum, by far the most dynamic telemark and backcountry skiing discussion board on the world wide web since 1998. East, West, North, South, Canada, US or Europe, Backcountry or not.
This is the World Famous TelemarkTalk / TelemarkTips / Telemark Francais Forum, by far the most dynamic telemark and backcountry skiing discussion board on the world wide web since 1998. East, West, North, South, Canada, US or Europe, Backcountry or not.
This is the World Famous TelemarkTalk / TelemarkTips Forum, by far the most dynamic telemark and backcountry skiing discussion board on the world wide web. We have fun here, come on in and be a part of it.
@randoskier "He has over 1000 km on his pulk. He paid $20 for the HDPE runners why blow another $20 on a tool you might use once or twice? He did a nice job."
Oh I'd blow the money for the tool, but I do have TAS as well as GAS
Yeah, exactly.
And if you plan, you might select a fastener of the same basic dimensions and drive type as a ski binding screw (eg. pozidriv #3 IIRC), so you need to take only one screwdriver on an excursion… that screwdriver can tighten skis, tighten HDPE runners, etc. Use the same screw heads for strips around the pulk and the harness… it’s all available at hardware stores and can simplify things.
The beveled bit will also allow you to mount ski bindings at some future point (helpful to prevent bucking or volcanos in the top sheet of the ski).
With a bit of planning, specialty fasteners and tools can make life a whole lot easier (and, yes, even cheaper in the long run).
We dreamed of riding waves of air, water, snow, and energy for centuries. When the conditions were right, the things we needed to achieve this came into being. Every idea man has ever had up to that point about time and space were changed. And it keeps on changing whenever we dream. Bio mechanical jazz, man.
@randoskier "He has over 1000 km on his pulk. He paid $20 for the HDPE runners why blow another $20 on a tool you might use once or twice? He did a nice job."
Oh I'd blow the money for the tool, but I do have TAS as well as GAS
@randoskier "He has over 1000 km on his pulk. He paid $20 for the HDPE runners why blow another $20 on a tool you might use once or twice? He did a nice job."
Oh I'd blow the money for the tool, but I do have TAS as well as GAS
Theme's solution wasn't not to create a bevel. He suggested first piloting the hole then using a larger standard bit to create the bevel.
So nobody suggested not recessing the screw.
Yup, I understand that.
A recessed hole is different than a beveled one.
A recessed hole will work fine for a dome head fastener, provided that the aim isn’t a flush fit. Obviously, this isn’t ideal because the hole itself creates drag (even if the edges are relieved). You can get around this by cutting and glueing in a plug, but high molecular weight plastics are very slippery… they don’t take glue well.
A beveled hole will work best for flat head fastener because the taper of the hole and bottom of the head will spread force. Having a slight recess to prevent the head from wearing is a reasonable compromise.
If you look at a drill bit, however, you’ll notice that it has a bevel. So they’re not the best for a dome head fastener (these fasteners are meant to sit on top of the material being fastened. They’re not even good for flatheads because the angles are different. Why? Because a standard drill bit is designed to drill *through* things.
It might be OK cranking things down but high molecular weight plastics are prone to splitting. When that happens, the only fix is replacement of the runner.
This is how fasteners are designed to work. They’re often used differently. Failure, obviously, is something worth avoiding in an application like a pulk used for any kind of distance skiing in the wilderness.
I know… people thing all this is bullshit, hogwash, etc. But it costs so very little to do the job correctly. At worst, it means the job is 20€ more. At best, it saves a headache on the trail and having to repurchase another set of runners/guides and do the whole goddam thing over again… with the 20€ in tools you had to buy on the second go around to do the job correctly.
There are valid points here but for the application that it is unnecessary. I'd say.
Drill bits (standard HSS ones) typically have a bevel angle of 118 degrees. ISO countersunk screws (which are the most likely to be used if you're on the right side of the pond) are typically 90 degrees. So yes, the angle is different.
However, in the low clamping force scenario, combined with the relatively low modulus of plastics, means that there will result in sufficient face angle contact for this very low stress application. Just look at the typical contact surface of a socket head bolt/machine screw and you'll see that there isn't much surface for the pressure.
Personally I have a 90 deg countersink bit (absolutely no need to have one with a pilot drill attached) which I use, however, I've used larger drill bits in the past with success.
1. If I did have the tools, I definitely would have done the bevel correctly to increase strength
2. I didn't, and could not be arsed to look for one for this project. I did take care that the shape roughly resembles that of the bolt's head
With this plastic, I felt it would only be in very extreme ends of the use range where such forces would be applied to the runners, that one would need to worry about the plastic splitting. It is a valid argument - I like to do things as well as possible, too. You would not believe the lengths of what I go to in some cases. A runner is not that critical - you can do without, and a critically damaged one is easily removed. If I knew I would do this again, I would get the correct drill bits. After all I ended up making three of these things.
We still do have two of them - one with 600km and one with 1600km. Both have been through a lot of abuse, from crashing into trees in full speed, to rolling around uncontrollably in too severe wind or a steep traverse where the contact was lost due to ice. The first one I made I sold to a friend.
When installing the runners, I could have gone without a recession for the bolts. The plastic allowed you to screw them in deeper than you drilled the holes, so there was some give that the shape was not absolutely necessary to be 100%.
What comes to the recessed holes on the runners, they do not drag at all, as they fill up with ice and snow 98% of the time. Dragging on roads, you could end up with gravel in the holes that could for a minute slow you down before releasing.
I know others that have used regular screws from the inside so they would not have this supposed drag. IMO that system has a higher chance of damage to the runners, and if they ripped off, more damage to gear from the screws could happen
1. If I did have the tools, I definitely would have done the bevel correctly to increase strength
2. I didn't, and could not be arsed to look for one for this project. I did take care that the shape roughly resembles that of the bolt's head
With this plastic, I felt it would only be in very extreme ends of the use range where such forces would be applied to the runners, that one would need to worry about the plastic splitting. It is a valid argument - I like to do things as well as possible, too. You would not believe the lengths of what I go to in some cases. A runner is not that critical - you can do without, and a critically damaged one is easily removed. If I knew I would do this again, I would get the correct drill bits. After all I ended up making three of these things.
We still do have two of them - one with 600km and one with 1600km. Both have been through a lot of abuse, from crashing into trees in full speed, to rolling around uncontrollably in too severe wind or a steep traverse where the contact was lost due to ice. The first one I made I sold to a friend.
When installing the runners, I could have gone without a recession for the bolts. The plastic allowed you to screw them in deeper than you drilled the holes, so there was some give that the shape was not absolutely necessary to be 100%.
What comes to the recessed holes on the runners, they do not drag at all, as they fill up with ice and snow 98% of the time. Dragging on roads, you could end up with gravel in the holes that could for a minute slow you down before releasing.
I know others that have used regular screws from the inside so they would not have this supposed drag. IMO that system has a higher chance of damage to the runners, and if they ripped off, more damage to gear from the screws could happen
Hi Theme,
What length are your runners and what thickness? (20mm thickness? 125cm length?) I like the up-turned nose you molded but I am not sure it is practical if you are using fiberglass traces to pull the pulk instead of rope. I ski mostly in Norway and northern Sweden and the only flats are traversing lakes, following rivers, and most of Finnmark. So I need solid traces. It would be hard to attach the traces to the sled with the up-turned lip. I have to put runners on two sleds (his and hers) so I will buy a set of runners for a larger ice-fishing sled- they use four runners so I can use two for each of our pulks. These runners come pre-drilled and counter-sunk and have all the mounting screws, washers (with gaskets), bolts, etc.
I need to install these runners for Finnmark because as you follow the Pasvik River south along the Russian border you arrive at a point around the Milke Foss (Milk Falls) extending to the Skogfoss where there are hydro-power installations and the associated weak ice, the only logical way to bypass this section is to ski 5km on the road, which is plowed but retains snow- you need runners to save your pulk bottoms from massive wear while following this road.
@randoskier "He has over 1000 km on his pulk. He paid $20 for the HDPE runners why blow another $20 on a tool you might use once or twice? He did a nice job."
Oh I'd blow the money for the tool, but I do have TAS as well as GAS
Yeah, exactly.
And if you plan, you might select a fastener of the same basic dimensions and drive type as a ski binding screw (eg. pozidriv #3 IIRC), so you need to take only one screwdriver on an excursion… that screwdriver can tighten skis, tighten HDPE runners, etc. Use the same screw heads for strips around the pulk and the harness… it’s all available at hardware stores and can simplify things.
The beveled bit will also allow you to mount ski bindings at some future point (helpful to prevent bucking or volcanos in the top sheet of the ski).
With a bit of planning, specialty fasteners and tools can make life a whole lot easier (and, yes, even cheaper in the long run).
I found a better solution. I bought a Hyfax runner kit for a large Otter ice-fishing sled. It contains six Hyfax runners, s/s mounting bolts, washers, and nyloc nuts. The runners are pre-drilled. I cut them to length, heat gunned the front curve bend, and drilled/screwed them on the pulk. The set is 70 bucks and can outfit 3 sleds so about $23 per sled, did our two sleds and have a spare. A further bonus is it respects the New York Mets color-scheme of my Paris sled set-up. I am thinking about bolting my Francisco Lindor bobblehead onto the bow of my sled.
Last edited by randoskier on Mon Mar 13, 2023 9:35 am, edited 2 times in total.
