Delrin parts work?

[Richard]

heres my frame and it cracked my head on the back by the cam chain tentioner and front by the header.

[Richard]

heres a little clip of where spring pucks will help with saving my bike.
right at the beginning is more or less what happened to my bike.
http://www.youtube.com/watch?v=M9oeeiRAB-4

[PhL0aTeR]

so a spring loaded frame slider is basically absorbs the shock so your frame doesnt have to?

[Richard]

thats the idea.
cages now are starting to be built too strong.
now they just move to the weakest point.
which is now the frame and motor.

[PhL0aTeR]

thats the idea.
cages now are starting to be built too strong.
now they just move to the weakest point.
which is now the frame and motor.

thats kinda what i was thinking... im building my pannier racks with a break point so if i have a tip-over, that point breaks, of which i will have an extra somewhere easily repaired on the road.

[Zach929rr]

There is a guy from springs I rode with that said he had access to delrin and worked at a mahine shop. Matthewb2204 or some shit.

[CYCLE_MONKEY]

heres my frame and it cracked my head on the back by the cam chain tentioner and front by the header.

From the pic I can tell you it was the cheap POS cage that broke your frame. See the mark made by the contact of the cage ONLY at the top of the engine mount on the frame? The cage did not fit correctly, meaning you had to overtorque the bolt to try and "bend" the cage and/or bolt to try and have the cage mount flush but still had a gap. This places tremendous stress on the bolt, frame, and engine. When you fell over, it went snap. It's not neccessarily that the cage is "too strong", it's just that it was a total POS and didn't fit right.

[Richard]

From the pic I can tell you it was the cheap POS cage that broke your frame. See the mark made by the contact of the cage ONLY at the top of the engine mount on the frame? The cage did not fit correctly, meaning you had to overtorque the bolt to try and "bend" the cage and/or bolt to try and have the cage mount flush but still had a gap. This places tremendous stress on the bolt, frame, and engine. When you fell over, it went snap. It's not neccessarily that the cage is "too strong", it's just that it was a total POS and didn't fit right.

that mark is from my old cage. thats why i changed to this one.

[CYCLE_MONKEY]

that mark is from my old cage. thats why i changed to this one.

Did the old one contact only at the top where the mark is, and have a gap on the bottom? If so, you could have severely weakened the bracket by torqueing the bolt down (creating a small crack). Castings tend to fracture like that. I've seen a few crashed bikes but never saw that kind of damage from a frame slider before. Could a spring-loaded puck have prevented this? That's too hard to say. Did the old cage sustain a hit? If so, that could be it right there.

[Cap'n Crunch]

I'm thinking for something as basic as those frame sliders, it may be easier to pick up a cheap (or used) manual lathe and just manually make them yourself. Like CycleMonkey said, using a CNC machine is great for large production runs or complex parts that need to be exact, but there is a lot of work that goes with it. If you wanted to make these on a CNC mill, you would need to draw the part up in a CAD program, then take the CAD file and bring it into a CAM program and spend a couple of hours setting up all the cuts. Then, from there you would need to export the G code from the CAM program and import it into CNC mill and spend some time getting the machine set up and zeroed out (several times). This is why the shops want to charge you a large amount of money, because there is a fair amount of work that needs to be done before the CNC mill is even started. On the other hand, if you manually ground these parts out on a lathe, you would probably be able to knock a couple of these out in an hour or two since they are basic round shapes. I don't have my own CNC machine (or lathe), but I would kill to get one in my garage one of these days...

[Richard]

Did the old one contact only at the top where the mark is, and have a gap on the bottom? If so, you could have severely weakened the bracket by torqueing the bolt down (creating a small crack). Castings tend to fracture like that. I've seen a few crashed bikes but never saw that kind of damage from a frame slider before. Could a spring-loaded puck have prevented this? That's too hard to say. Did the old cage sustain a hit? If so, that could be it right there.

yes, the old cage did hit there. it didnt have a spacer or cross bar like this new cage does. as in the pic, you can see where the spacer keeps the bracket off of the frame. the old cage would always hit there on impact. and for the cross bar, it keeps the cage from being bent up or down. my old cage didnt have one. so on impact, it would bend it up or down. causing the impression thats was left. and for cracks, i inspect my frame weekly. cracked frames are a big problem in the stunt community. not saying that something else couldn't have weakend that spot, but there weren't any cracks before i went out of town.

I'm thinking for something as basic as those frame sliders, it may be easier to pick up a cheap (or used) manual lathe and just manually make them yourself. Like CycleMonkey said, using a CNC machine is great for large production runs or complex parts that need to be exact, but there is a lot of work that goes with it. If you wanted to make these on a CNC mill, you would need to draw the part up in a CAD program, then take the CAD file and bring it into a CAM program and spend a couple of hours setting up all the cuts. Then, from there you would need to export the G code from the CAM program and import it into CNC mill and spend some time getting the machine set up and zeroed out (several times). This is why the shops want to charge you a large amount of money, because there is a fair amount of work that needs to be done before the CNC mill is even started. On the other hand, if you manually ground these parts out on a lathe, you would probably be able to knock a couple of these out in an hour or two since they are basic round shapes. I don't have my own CNC machine (or lathe), but I would kill to get one in my garage one of these days...

yea man, i was just trying to see if anyone here locally did any of this in there spare time. like i was saying before there was a guy in OKC on a local forum that would make frame sliders for around 20 bucks that look just like most other sliders. he had his own cnc machine and would do it on his spare time. its really not too outrageous of a price for my sliders. $30 a set, from sick innovations. i was just trying to save a few bucks and get it done locally.

[CYCLE_MONKEY]

yes, the old cage did hit there. it didnt have a spacer or cross bar like this new cage does. as in the pic, you can see where the spacer keeps the bracket off of the frame. the old cage would always hit there on impact. and for the cross bar, it keeps the cage from being bent up or down. my old cage didnt have one. so on impact, it would bend it up or down. causing the impression thats was left. and for cracks, i inspect my frame weekly. cracked frames are a big problem in the stunt community. not saying that something else couldn't have weakend that spot, but there weren't any cracks before i went out of town.
Not that you were able to see. Castings are very susceptable to fracture like that. It may have been a hairline crack, just enough to weaken it.

yea man, i was just trying to see if anyone here locally did any of this in there spare time. like i was saying before there was a guy in OKC on a local forum that would make frame sliders for around 20 bucks that look just like most other sliders. he had his own cnc machine and would do it on his spare time. its really not too outrageous of a price for my sliders. $30 a set, from sick innovations. i was just trying to save a few bucks and get it done locally.
I think, as you found, trying to do it yourself as a "one-off" via a machine shop vs. mass production, well, you'll never be able to compete in $$.

...

[Richard]

Not that you were able to see. Castings are very susceptable to fracture like that. It may have been a hairline crack, just enough to weaken it.

yea, maybe it was just one that i may have missed. but, i kind of pride myself in crack finding. just cause thats what i used to do, with aircraft parts and equipment. hopfully there aren't a bunch of planes out flyin around with faulty equipment.

[PhL0aTeR]

i kind of pride myself in crack finding.

hey, me too!

FWIW, theres a guy on ADV who responded to my post on the subject, seems like he would be willing to crank something out, here is the thread, check out post #11

http://www.advrider.com/forums/showthread.php?t=705242