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Post by darren on Jan 21, 2006 4:47:08 GMT
Has anyone tried to tap 2 brass tubes into the rocker pivot points, and flare the end. I figure if I drill the holes out a bit, and insert brass tubing, I can tap the threads into the brass to match the pivot pins. I can flare the ends (like a lock washer) to ensure they don't pop out. It seems like this may work...of course...it may turn out like my dogbone idea too...
Any thoughts?
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Post by chris burgess on Jan 23, 2006 14:27:19 GMT
It might work, Darren, but I think the big problem you have is the lack of plastic around the area you will be drilling. There's not much as it is, so to take even a little more away is going to weaken that area more.
I have looked into having the front gearbox tops made out of alloy, but apparently by the time the wax moulds are made, and they are cast and finished, I would need to get at least 2-3 hundred made.....
anyone want to get a bulk buy going? ;D
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Post by Cooper on Jan 23, 2006 14:43:16 GMT
ttech should just make his gearbox tops better, this is the only weak point still left from all those years. I've got in my head how it should be, but In can only think ofcourse  I could make a CAD one day but it would have no use because it won't be made anyway |
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Post by Northy on Jan 23, 2006 19:14:05 GMT
I have looked into having the front gearbox tops made out of alloy, but apparently by the time the wax moulds are made, and they are cast and finished, I would need to get at least 2-3 hundred made..... I have been thinking exactly the same thing. I think the hardest part would be getting the holes drilled accuratley  |
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Post by chris burgess on Jan 23, 2006 19:22:08 GMT
I have looked long and hard at the front gearbox, to see if it can be modified in anyway to increase strenght, and I cannot see a way to improve it, other than to change the material.
A change to aluminium would be ideal, and looking at the car, there doesn't seem to be anything (else) that would be damaged in a hard frontal collision by the adition of an alloy cover, except in a major shunt, the area that the gearbox bolts to the chassis, or maybe the carbon brace, as it is such an "all-in-one" solution to the front end.
It's simply the cost incurred that stops me from exploring further.
I will, if there is sufficient interest, get some proper pricing from different sources, to see if it is a worthwhile step.
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Post by Northy on Jan 23, 2006 19:32:38 GMT
I wonder if milling would be a better option for small volumes. There is no need for it to be as complex, but it would still be a hell of a mission!
We have a local company that we use at work, next time I'm there to see them (on company time ;D ) I'll take one for them to look at. Would be nice if someone could CAD it though, Coop!
Only other thing I have thought about is a bracw between the two to share the force a little.
G
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Post by Cooper on Jan 23, 2006 19:45:30 GMT
CAD would be alot of hours work, though I could design it so it wouldn't have to be in aluminium. i'll edit some pictures in paint to try to explain my modifications. I've mailed 1 of them to richard once and his reply was 'thanks for your input' thats all LOL ... CAD will be next stage, need to find the time |
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Post by Cooper on Jan 23, 2006 20:09:30 GMT
 Ok, look at the yellow that is where richard went wrong when you have a hole, the distance with the side has to be [k* diameter hole] (with k between 1.5 and 2.5 for various materials, mostly metal) that's why I added the red stuff, it's just a rough idea but it will settle itself once it will be in CAD. any suggestions or whatever are very welcome |
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Post by darren on Jan 25, 2006 2:55:32 GMT
Hey Chris,
I wouldn't remove more than 1.5mm from either holes total circumferance. I have thin enough tubing. I am going to try it tonight and will advise in a day or two...no...I am off to the Nue. toy fair, maybe when I come back....
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Post by chris burgess on Jan 25, 2006 11:07:58 GMT
even 1.5mm overall sounds a lot on that area of the gearbox, but it's certainly worth trying.
Graham - I also enquired about having the gearbox top milled instead of cast, and the bloke took a VERY deep breath and then started to look for a new ferrari!
Apparently a milled gearbox top would be more expensive than a cast one, at least from that source anyway.
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Post by Cooper on Jan 25, 2006 11:54:18 GMT
LOL.... it's one of the most complex molded pieces I've ever seen on an RC car, making this in CNC is still ALOT of work, the trick it to make it less complex and maybe it will be affordable. The part where the rockers, crash pins, bearing are located is the difficult thing, if I succeed in makin it simple in CAD we could have a starting point. I think I'll buy myself some Play-Doh and try this first before I start spending hours in CAD. (let's have a -modify your gearboxtop in PlayDoh contest  - |
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Post by Northy on Jan 25, 2006 12:52:51 GMT
Yeah, thats what I was meaning Coop, simplify it before milling it.
I might have a play if I get time.
G
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Post by Cooper on Jan 25, 2006 13:25:17 GMT
i've took an old gbtop, installed a rocker and now I need some playdoh
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Post by Northy on Jan 25, 2006 13:32:52 GMT
Go Coop! ;D Some of us have to work.  |
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Post by Cooper on Jan 25, 2006 13:43:45 GMT
Go Coop! ;D Some of us have to work. some of us need to study fluid mechanics |
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