Keeping the core and edge set in place using the pressure created by the tip spacers.
More Monkey business
Moderators: Head Monkey, kelvin, bigKam, skidesmond, chrismp
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doughboyshredder
- Posts: 1354
- Joined: Mon Sep 17, 2007 7:37 pm
Thanks DBS - semi capped-ish. Still need to find the right router bit, so its a bit of a compromise.
The jigs I use give me the accuracy needed, but its all down to that strip of plastic.
I have a few more holes in the aluminium tips than I would like - doh. I used the press form the tips and a few holes moved. Anyway, if this works, I will replace them so I can lay up two at a time and reset the curve of the tips to reflect the edge bender I am using. This should lead to a highly accurate fit. Bending the edge set upwards into the cassette by hand is a lot easier than bending them to fit a flat base. If this works this may lead to capped tips in the future... well I'll know later on today whether this is all hot air.
The jigs I use give me the accuracy needed, but its all down to that strip of plastic.
I have a few more holes in the aluminium tips than I would like - doh. I used the press form the tips and a few holes moved. Anyway, if this works, I will replace them so I can lay up two at a time and reset the curve of the tips to reflect the edge bender I am using. This should lead to a highly accurate fit. Bending the edge set upwards into the cassette by hand is a lot easier than bending them to fit a flat base. If this works this may lead to capped tips in the future... well I'll know later on today whether this is all hot air.
Last edited by Richuk on Sun Oct 17, 2010 11:31 am, edited 2 times in total.
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skidesmond
- Posts: 2337
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Cheers guys - pressing at the moment ... had to reset everything mid lay up. It's fair to say that there are a few practical problems to overcome 
Apart from the edges being different widths - trying to save wood
Happy with how the cores turned out. Avoided a large part of the bonding issue with this method, cheaper and I hope to get a flash of wood when they are finished. I cheated and used ABS - will use it up before switching to PE.
Having a few problems with the new blankets tripping out the 16A fuse - it's an RCD, so I'm not too worried, as I was able to turn down the power - using only 80 volts and then monitor throughout the heat cycle. I suspect I have a problem with my earth, as I am not over loading the unit. The new epoxy was strange - I should have warmed it up, although it wets out really well, but very different to the previous lot. Used a lot more, but didn't wet it as much as I should - sorry OAC.
There you go, got all my excuses in early!
Apart from the edges being different widths - trying to save wood
Happy with how the cores turned out. Avoided a large part of the bonding issue with this method, cheaper and I hope to get a flash of wood when they are finished. I cheated and used ABS - will use it up before switching to PE.Having a few problems with the new blankets tripping out the 16A fuse - it's an RCD, so I'm not too worried, as I was able to turn down the power - using only 80 volts and then monitor throughout the heat cycle. I suspect I have a problem with my earth, as I am not over loading the unit. The new epoxy was strange - I should have warmed it up, although it wets out really well, but very different to the previous lot. Used a lot more, but didn't wet it as much as I should - sorry OAC.
There you go, got all my excuses in early!
Last edited by Richuk on Sun Oct 17, 2010 5:29 am, edited 2 times in total.
So I need some help analysing these results - everything welcome.
CF stayed in place - applied to a dry core. The top of the cassette located itself just as I wanted.
The epoxy looks flat because of the painters polyethene - used as a final wrap.
Hence the creased epoxy
Expansion gave a really good fit around the edges, but I do need to re-work the tips, so that they match the mold. Maybe ... they did pop out at the other end. They were tight when they went in.
Hmm ... lack of pressure in this spot, laid up incorrectly not sure.
The core stayed in place laterally, not sure yet about fore aft
CF moved laterally, I suspect I caused this when placing the core into the mold - had to replace everything, so I was a bit of a learners day out.
I'd say 18 mm, instead of the designed 12 mm - I had to heat the bottom and then, using a reduced voltage, allow the top to come up to temperature. Not surprised to see increased camber as a result.
New epoxy is really tough already ... so I will remove the flash and try and get to grips with what needs to be changed for the future.
This came out of the cassette without much stress.
CF stayed in place - applied to a dry core. The top of the cassette located itself just as I wanted.
The epoxy looks flat because of the painters polyethene - used as a final wrap.
Hence the creased epoxy
Expansion gave a really good fit around the edges, but I do need to re-work the tips, so that they match the mold. Maybe ... they did pop out at the other end. They were tight when they went in.
Hmm ... lack of pressure in this spot, laid up incorrectly not sure.
The core stayed in place laterally, not sure yet about fore aft
CF moved laterally, I suspect I caused this when placing the core into the mold - had to replace everything, so I was a bit of a learners day out.
I'd say 18 mm, instead of the designed 12 mm - I had to heat the bottom and then, using a reduced voltage, allow the top to come up to temperature. Not surprised to see increased camber as a result.
New epoxy is really tough already ... so I will remove the flash and try and get to grips with what needs to be changed for the future.
This came out of the cassette without much stress.
Last edited by Richuk on Tue Oct 26, 2010 1:08 pm, edited 4 times in total.
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
Will double check.
Yep - gave the mix and match a try. I like the effect, but would consider reducing to 2mm in the future, so that a clear topsheet would show only wood. Will look better when a dark topsheet is applied.
The bleed looks worse than it is (cough cough) I just need to back off the amount I apply to the edge and VDS.
Epoxy is Sicomin SR8500/SZ8525.
This is the problem - the edges popped here at the tip. Not much on the left, but a lot on the right.
Yep - gave the mix and match a try. I like the effect, but would consider reducing to 2mm in the future, so that a clear topsheet would show only wood. Will look better when a dark topsheet is applied.
The bleed looks worse than it is (cough cough) I just need to back off the amount I apply to the edge and VDS.
Epoxy is Sicomin SR8500/SZ8525.
This is the problem - the edges popped here at the tip. Not much on the left, but a lot on the right.
Last edited by Richuk on Mon Oct 18, 2010 3:09 pm, edited 1 time in total.
if you wish to stop the CF wandering you can superglue or hot glue them to the core prior to layup then wet the CF and core out when you do the layup. Folsom customs seem to do this.
Not that I come from any experience of cassettes at all but I reckon the popping out of the edges is because the cassette fit wasn't tight enough.
Not that I come from any experience of cassettes at all but I reckon the popping out of the edges is because the cassette fit wasn't tight enough.
Don't wait up, I'm off to kill Summer....
Thks Falls, I think I will have to do that in the future.
At this stage, I'm looking for a 'say what you see response', then I hope to publish what I have learnt and add to what is available to the forum.
I'm going to do a couple of dry lay ups and see if I can work it out. The tip with the least curvature (profile view) popped. Perhaps I'm not getting the pressure where I need it. I think I will move the aluminium buffer at the end closer to the end of the tip, so when the plastic snaps in, it pressures the joint even before reaching the press. The other option is pre-heating the plastic into shape, but this would add to the process and that's not the aim of the game right now.
I'm hoping part of the problem is because I didn't trim the edge set correctly and that's why one side popped out more than the other??? It was difficult to judge when trimming for the cassette.
Tighter ... there is a bit of epoxy on the edge, so I might need to tighten up, but that's a bit tricky to do once they have been screwed into place. I was happy with how the length of the ski popped out post cure. The tips needed a bit of help. Nothing to worry about, tiny amount of epoxy escaped and held them back.
Btw, I think the application tape, which was slight embossed with a cross hatch, has left an imprint on the top of the ski. Like it.
There was a bit of movement ... the front tip is pressured slightly before the rear and has moved the core to the rear?
So hopefully this adjustment will help - buffer has been moved closer
Btw, the core did move laterally ... rebating the sides on the AL was a mistake, should have set them at 88 degrees. It would have been a shorter manufacturing process too.
At this stage, I'm looking for a 'say what you see response', then I hope to publish what I have learnt and add to what is available to the forum.
I'm going to do a couple of dry lay ups and see if I can work it out. The tip with the least curvature (profile view) popped. Perhaps I'm not getting the pressure where I need it. I think I will move the aluminium buffer at the end closer to the end of the tip, so when the plastic snaps in, it pressures the joint even before reaching the press. The other option is pre-heating the plastic into shape, but this would add to the process and that's not the aim of the game right now.
I'm hoping part of the problem is because I didn't trim the edge set correctly and that's why one side popped out more than the other??? It was difficult to judge when trimming for the cassette.
Tighter ... there is a bit of epoxy on the edge, so I might need to tighten up, but that's a bit tricky to do once they have been screwed into place. I was happy with how the length of the ski popped out post cure. The tips needed a bit of help. Nothing to worry about, tiny amount of epoxy escaped and held them back.
Btw, I think the application tape, which was slight embossed with a cross hatch, has left an imprint on the top of the ski. Like it.
There was a bit of movement ... the front tip is pressured slightly before the rear and has moved the core to the rear?
So hopefully this adjustment will help - buffer has been moved closer
Btw, the core did move laterally ... rebating the sides on the AL was a mistake, should have set them at 88 degrees. It would have been a shorter manufacturing process too.
Last edited by Richuk on Sun Oct 24, 2010 3:52 am, edited 1 time in total.
Found a fix - more to do. Found someone locally with a slip roller, as I think I can see a few issues with uneven pressure, hence a few pools of epoxy around the edges.
A few unintended gaps are appearing, happily not around the tips. I can't see a pattern ... perhaps it's how I shave the base after it has been cut to shape? I will be re-shaping the mold over the next couple of weeks, putting everything right.
Intend to sort out how I am wrapping the edges - one piece.
General design tips about anything to do with the core, placement of laminates would be appreciated. PM me, especially if these postings are helping you out.
A few unintended gaps are appearing, happily not around the tips. I can't see a pattern ... perhaps it's how I shave the base after it has been cut to shape? I will be re-shaping the mold over the next couple of weeks, putting everything right.
Intend to sort out how I am wrapping the edges - one piece.
General design tips about anything to do with the core, placement of laminates would be appreciated. PM me, especially if these postings are helping you out.