Cutting out the base
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
i dont know if this will help, but i have large rolls of snowboard base material that I am cutting skis out of. Rather than dragging a shop knife over the base, i do the opposite. Basically, I lightliy engrave the shape of the ski in the base material, then pierce the knife all the way through at one end and rather than pulling the knife, the knife is stuck into wood underneath and I pull the base. The light engraving gives a guide to follow and the base comes out to the exact shape....I dont know if this will solve your problem, but none of my bases have warped yet
Base Cutting
Hey Guys,
Your sight rocks! My buddy and I are working on a company Avant Skis, which will also be my final/senior project for my BFA in Design at Alfred University, NY.
Has anyone tried a hot knife or blade to cut the base material. Because of the temprature effects I am not sure if it would make the warping worse, but it seems like it would allow the blade to cut with a cleaner edge and cause less stress/stretch while draging the blade??
Your sight rocks! My buddy and I are working on a company Avant Skis, which will also be my final/senior project for my BFA in Design at Alfred University, NY.
Has anyone tried a hot knife or blade to cut the base material. Because of the temprature effects I am not sure if it would make the warping worse, but it seems like it would allow the blade to cut with a cleaner edge and cause less stress/stretch while draging the blade??
I have been reading this with great interest, and was wondering which brands of base material you guys are using and if that would make a difference. I have Durasurf available here locally, but would look else where if this is a common problem.
Has anyone tried to heat treat the plastic before you cut out your part to see if the internal stress would relax some after it cools back down. I know you can't tell there is a problem until the part is cut. It looks like a few people already have problem materials and it could be worth a try.
Awesome site guys. Thanks for providing the info. I'm looking forward to making some skis and other toys here real soon.
Hafte
Has anyone tried to heat treat the plastic before you cut out your part to see if the internal stress would relax some after it cools back down. I know you can't tell there is a problem until the part is cut. It looks like a few people already have problem materials and it could be worth a try.
Awesome site guys. Thanks for providing the info. I'm looking forward to making some skis and other toys here real soon.
Hafte
durasurf
Seeing as I have just ordered my base material form Durasurf yesterday and had read here about warping issues, I asked the rep at Durasurf about it. All I got out of the conversation is that you should use a cnc set-up to cut the base material. People who use this method don't have issues.
Well, I don't have a cnc set up and am trying desperately to keep the costs down I figure that the router on a template is the best option. I Know this post was old but any new insight on this.....
Help
rockaukum
Well, I don't have a cnc set up and am trying desperately to keep the costs down I figure that the router on a template is the best option. I Know this post was old but any new insight on this.....
Help
rockaukum
Hi there.
Maybe a good tip to share:
I always laminate a thin ply of fiberglass fabric (0.1mm) with peel-ply on the UHMW base BEFORE cutting. This is to stabilize the base.
You can also laminate some kevlar fabric for bullet-proof construction. The curing must be done at room temperature to avoid thermal distortion.
The kevlar reinforced base is just a little harder to cut but no significant difficulties compared to the advantages.
This has also the benefit to protect the very fragile surface prep of the base (flame treatement) when cutting the base and bonding the edges.
(I keep the peel-ply when cutting the base, and remove it before bonding the edges)
It also sounds good to me to bond edges on a reinforced surface like fiber (particularly on kevlar for damping properties) since both UHMW base and steel edges are made of material that are difficult to bond perfectly (or with fragile surface preperation). But maybe, someone has different experience or theory about that.
I hope this help.
Kwetsor
Maybe a good tip to share:
I always laminate a thin ply of fiberglass fabric (0.1mm) with peel-ply on the UHMW base BEFORE cutting. This is to stabilize the base.
You can also laminate some kevlar fabric for bullet-proof construction. The curing must be done at room temperature to avoid thermal distortion.
The kevlar reinforced base is just a little harder to cut but no significant difficulties compared to the advantages.
This has also the benefit to protect the very fragile surface prep of the base (flame treatement) when cutting the base and bonding the edges.
(I keep the peel-ply when cutting the base, and remove it before bonding the edges)
It also sounds good to me to bond edges on a reinforced surface like fiber (particularly on kevlar for damping properties) since both UHMW base and steel edges are made of material that are difficult to bond perfectly (or with fragile surface preperation). But maybe, someone has different experience or theory about that.
I hope this help.
Kwetsor
I also was originally planning to use kevlar on my base also to prevent core shots. steel edges and uhmw are tough to bond to, but kevlar is also far worse for bonding than carbon or glass. kevlar is the most likely to delam, this is why it is rarely used for compression because it may release from the matrix. if i knew this wouldnt increase the chances of delam i would like the idea of reinforcing the base material. are you able to prebend the edged base after, despite the cured fiberglass?
I do admit you are right with the kevlar: no good in compression.
But laminated on the base, under the wood core, no compression occurs.
Keep in mind that the laminate is very thin, so I have never met any problem when prebending the edged base.
Regarding the bonding properties, I trust the sizing of the aramid fiber made by the supplier to be compatible with epoxy resin.
You could also tell that kevlar is very sensitive to water (absorbent) and this is more a bad new for delamination problem. In this configuration, the steel edge will actually protect the kevlar from moisture.
Whatever kevlar or not, this was about stabilizing the core before cutting
But laminated on the base, under the wood core, no compression occurs.
Keep in mind that the laminate is very thin, so I have never met any problem when prebending the edged base.
Regarding the bonding properties, I trust the sizing of the aramid fiber made by the supplier to be compatible with epoxy resin.
You could also tell that kevlar is very sensitive to water (absorbent) and this is more a bad new for delamination problem. In this configuration, the steel edge will actually protect the kevlar from moisture.
Whatever kevlar or not, this was about stabilizing the core before cutting