trials hoe Posted June 8, 2013 Report Share Posted June 8, 2013 bee's wax worked a treat rigged a quick mould (type thing) together with some g clamps and some cut up laminate floor (leftovers), just so i knew what the 70a compound was going to be like...the wait for me to get a proper mould together was going to be too long with me being an impatient twat. frankly i could have done a much better job, but this was more about 'knowing' than anything else. performance is bang-on other than the squishiness of the pad it's self, i'm aiming towards a pad for a smooth rim rather than a ground one (grind in the pic is dead) but they won't last overly long on a grind, that said for how much the mix cost vs how many pads it makes its viable to run a grind too from a cost perspective. anyhoo...any PU gurus on here? are there and additives i can add to the mixture before moulding to reduce the amount of compression the end product has? abuse opinions are welcome on my piss-poor effort Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 8, 2013 Author Report Share Posted June 8, 2013 respect! micro balloons are stiffening up the stuff,or fiber powder Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 8, 2013 Report Share Posted June 8, 2013 respect! micro balloons are stiffening up the stuff,or fiber powder cheers just had a look at those microballoons, sounds like they're designed towards reducing density and cost (yet to see anything about an additive reducing the amount of compression) in my head something less dense will compress more? or some kind of 'fibers' sounds like a better shout to me, a bit like chopped strand glass fiber maybe? .don't want to add anything that will affect the 'performance' of the pads grip/bite on the rim. Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 9, 2013 Author Report Share Posted June 9, 2013 i´m tempted to use pigments too,but for now i ordered a fireproofing agent,the guy said it reduces the wear and gives some stiffness(hardens it up by 2-10 degrees shore,depending on how much you add) maybe this? Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 9, 2013 Report Share Posted June 9, 2013 i was watching a vid on pootube the other day, a SFX company made a pair of scissors and they used 2 different types of the pu stuff (can't remember which ones exactly) one to keep the rigidity of the shape and one (think it was the 60a shore version of the one i got) to make them 'soft' enough to allow them "to be thrown at people in the office." i'll have a look for it in a bit, could be an option to mix in a small % of something that would be rigid enough to give the pad a more solid feel without making it too much harder shore wise. or i might go find a relevant forum and ask on there, someone will have had the same problem an found a solution to it. Quote Link to comment Share on other sites More sharing options...
picowatt Posted June 10, 2013 Report Share Posted June 10, 2013 There is 80a and 85 a polyurethane on eBay in sheets and square blocks in various colors. Has anyone tried these? I am currently using rockman blues. What is the estimated shore value? Quote Link to comment Share on other sites More sharing options...
Blake Posted June 10, 2013 Report Share Posted June 10, 2013 Im still waiting for money, damn being poor Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 10, 2013 Report Share Posted June 10, 2013 There is 80a and 85 a polyurethane on eBay in sheets and square blocks in various colors. Has anyone tried these? I am currently using rockman blues. What is the estimated shore value? i bought some of these ( http://www.ebay.co.uk/itm/Magura-Rim-Brake-Pads-Orange-HS11-HS22-HS33-HS66-HS77-/200726832758?pt=UK_sportsleisure_cycling_bikeparts_SR&hash=item2ebc406676 ) ages ago, the pad compound and colour is pretty similar to the 70a compound ones i made if that helps....but i'd guess and say most pads are upwards of 90a myself, but that said i don't know how much difference 5/10 shore difference will make...i can say the 70a is a lot softer than the cousts i have how much are the pre-made blocks for how much quantity? the 2 part mix i got was 20 quid for 500g (total) should get 50/60 pads out of that much of the mix once i get a mould made, cutting the shape of the pad recess isn't fun at all. Quote Link to comment Share on other sites More sharing options...
picowatt Posted June 10, 2013 Report Share Posted June 10, 2013 Ok. I have those same exact pads on a small mod with smooth rims we use as a beginner bike to get friends to ride. That's a good sense of what 70a feels like then. 80 a may be what I am after then. Something a little more resistant for a light grind. http://item.mobileweb.ebay.com/viewitem?itemId=170926968680&index=7&nav=SEARCH&nid=77521732930 Here's one I was thinking of getting and trying Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 10, 2013 Report Share Posted June 10, 2013 the ones i made are pretty damn good on a dead grind, the pads i linked i've run on a harsh grind in the past and they were savage but they did wear fast though...but if you're making your own pads its not that much of a worry, just bang some more on. advantage of buying it in its 'finished' state will probably work out more expensive, but you don't have to worry about air bubbles and making a mould or mixing ect. to everyone - are we planning on posting different compounds to each other to try? would be nice to try different compounds without having to buy more haha Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 10, 2013 Author Report Share Posted June 10, 2013 are we planning on posting different compounds to each other to try? would be nice to try different compounds without having to buy more haha i´m in for this idea Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 10, 2013 Report Share Posted June 10, 2013 once I've got a mould sorted I'm going to make as many pads as I'll get out of the mix i have, so I'll have a few spare that I wouldn't mind sending out to someone for a second opinion in return for the same. any thoughts on pouring into a mould then (using a 2-piece mould) applying pressure to it while it cures (poor-mans way of trying to replicate injection moulding)? i'm guessing all the other pads are injection moulded, curious as to if there are any other benefits to the material's performance or if its a costing/production time reason. Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 10, 2013 Author Report Share Posted June 10, 2013 its quicker,and the pre-heating of the moulds makes it even quicker. i think we can produce pleasing results with just doing it by hand(insert masturbation joke here),playing around with different fillers/pigment/heat treating the stuff afterwards moulding would bring more difference in performance than anything imo Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 10, 2013 Report Share Posted June 10, 2013 its quicker,and the pre-heating of the moulds makes it even quicker. i think we can produce pleasing results with just doing it by hand (if I could knock out as many pads as I do wanks I'd be rich),playing around with different fillers/pigment/heat treating the stuff afterwards moulding would bring more difference in performance than anything imo yeah, just having a 1-ipece pour-in mould is going to be the cheapest/least hassle approach. was looking for fillers/powders additives before and found a page with it written nice and simple as to what powders did what, some increase the amount of friction and some reduce it...so you could use a harder compound shore, add an additive that increases friction an you'd end up with the equivalent of a softer compound once its used as a brake pad? still trying to work out what would be the best material to make a mould/blank from, starting to look a modeling clay it's easy to find and to work with, then it can be fired in the oven at home...good idea? Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 10, 2013 Author Report Share Posted June 10, 2013 (edited) i think it shrinks a fair amount when in the oven.meaning too big pads,which should be okay Edited June 10, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 10, 2013 Report Share Posted June 10, 2013 (edited) so if i made a blank, fired it then if i took a mould of the blank (after firing) it would be the same as the blank was before it was fired? think that makes sense, if the shrinkage was the same during both processes it would work it's self out... Edited June 10, 2013 by trials hoe Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 10, 2013 Author Report Share Posted June 10, 2013 just make the mould,it was mentioned before that a minimal too big pad is a good thing for having maximum backing compability. i think i´ll go for clay too,just going to take a block and press the refill into it several times,bake it,boing! Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 10, 2013 Report Share Posted June 10, 2013 I need to make a blank first, otherwise I'll end up with pads with like 5mm life in 'em haha sounds like a fail-proof plan though Quote Link to comment Share on other sites More sharing options...
picowatt Posted June 11, 2013 Report Share Posted June 11, 2013 That's about how much those plasma tic CRV pads had Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 11, 2013 Author Report Share Posted June 11, 2013 think i´ll take an old pad refill,screw a bolt into it from the brake face and use it as some kind of stamp to press into the clay... so the mould hole is deeper,more pad height Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 11, 2013 Author Report Share Posted June 11, 2013 (edited) haha,received my echo cnc backings today and have to say that echo refills have smaller recesses(1.5mm each side front and back) BUT a bigger pad block(around 1-2mm wider than a powerpad backed pad "refill" so the perfect pad to size it down to every other backing would be having the recess shape of a plastic backing and the pad block shape of a cnc,which is around 50x11x?(pad height)mm just wanted other scientists to know lol edit:whats the cnc refill sizing of your pads,guys?just want to clear up if every pad model has a diferent shape,would complicate things a bit... Edited June 11, 2013 by FamilyBiker Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 11, 2013 Report Share Posted June 11, 2013 mine measured 48mm x 7mm x 4.5mm (18mm x 11mm for the recess bits) an the heatsink backings i got in the post yesterday are the same only the central bit of the recess is 10mm not 11mm think they're all a tad different, which is lame haha Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 14, 2013 Author Report Share Posted June 14, 2013 i´m gonna be the one who´ll be trying pigments then,just ordered some. my mixture will be pu 80a fireproofing agent pigment liquid comes out mathematically as 86a,high friction,low abrasion compound yay Quote Link to comment Share on other sites More sharing options...
trials hoe Posted June 14, 2013 Report Share Posted June 14, 2013 pigment as in colour? was looking at it but they only had the same colours as pad refills that are on sale, if i was going to add colour it'd have to be something different....might get some black though, want to get everything else sorted before i start fannying around with aesthetics you looked into powdered metal additives? remember looking at one that increased the amount of friction and improved the wear life too, buggered if i can remember what powder it was will have a look see if i can't stumble across it again haha Quote Link to comment Share on other sites More sharing options...
FamilyBiker Posted June 15, 2013 Author Report Share Posted June 15, 2013 aluminium hydroxide. thats the fireproofing agent i was talking about,it hardens the mix up,gives heat resistance and increases friction. ali c mentioned in a thread about a similar topic that pigments change the properties of the pads,too,so i thought why not. getting an aubergine colour tone,hopefully it wont turn out purple lol Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.