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Post by R2S on Jan 5, 2014 22:01:54 GMT
Anyone out there used rivnuts in their build?
I am particularly keen to have a transmission tunnel which is easy to take off/replace and using rivnuts in the chassis seems the perfect solution.
couple of other ares where being able to remove panels might be advantage, side exhaust and catalyst access being just two.
I am interested in size of RivNut to use and tools required?
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Post by nzexo on Jan 6, 2014 0:20:07 GMT
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Post by Paul (madeye) on Jan 6, 2014 7:56:04 GMT
I would advise drilling and tapping first where possible, it removes much less material from the chassis members with the same results. If you fail with m4, you can try m5 and 6 before going to rivnut.
I have not used a single rivet or rivnut yet, they are my back up options.
Paul
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Post by snowbird1 on Jan 6, 2014 14:12:00 GMT
I agree with Paul about not removing material, I use a sharp punch to start a hole then open it up to the required tapping size with a tapered drift, if the material is too thick to punch - drill a small hole then open it up. If you want to sound professional the process is called swaging. Remember to coat the threads with a rust preventer like HS2000 or Dinitrol.
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Post by nitram on Jan 7, 2014 12:46:43 GMT
I was very happy with my Memfast tool - a quality product. I found that I mainly used M6 and M8 and just a few M4 and M5.
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Post by kiwicanfly on Jan 14, 2014 9:02:59 GMT
I agree with Paul about not removing material, I use a sharp punch to start a hole then open it up to the required tapping size with a tapered drift, if the material is too thick to punch - drill a small hole then open it up. If you want to sound professional the process is called swaging. Remember to coat the threads with a rust preventer like HS2000 or Dinitrol. There is a process caled flowdrilling that uses a high speed tool to swage tubes and plates to make them ready for tapping. The tool heats up the wall and hot forms the material into a tapable shape. It is the best way to tap thin walls but you need a really solid dril press. I was hoping to use it but it was no use in a hand held drill. |
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Post by Paul (madeye) on Jan 14, 2014 9:09:34 GMT
what about a mag drill??
that gave me an underpant twitch.. think I have issues..
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Post by kiwicanfly on Jan 14, 2014 9:33:26 GMT
I thought about a mag drill but unusually went the easy route and tapped direct. It is pretty impressive to watch in real life though. We were considering it in a project for making SS handles but it did not fly. Should have factored in the Rocket - amazing how figures suddenly add up when there is a personal interest.  |
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Post by Paul (madeye) on Jan 14, 2014 9:49:30 GMT
are the bits expensive? do they just sit in a standard pillar drill, they give so much more threaded surface area. how many passes do they get before they are funked.
im sure a jig could be made to hold a mag drill square on a 2" tube..
im really impressed with that.
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Post by kiwicanfly on Jan 14, 2014 20:52:56 GMT
From memory they last a hell of a long time when used properly can't remember actual figures though.
You would have to check locally for a price, NZ300 rings a bell but could be wrong.
BUT, if you have already drilled all your holes it is too late, they have to go in blind and you also really should use a roll tap as well.
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Post by R2S on Jan 14, 2014 22:14:20 GMT
Thanks for the responses thoughts/comments are:-
Providing hole used for rivnuts is no greater than hole to be used for rivets I'm not sure how this can make it any weaker? Dont forget i am only talking about light wt panels so don't need large bolts or set screws.
Drilling and tapping only allows a depth of thread as deep as chassis/material thickness where as (if i understand correctly) rivnut gives deeper threaded section.
Flow drilling not an option as chassis is powder coated so any heat build up will damage surrounding area.
Not sure of the benefits of mag drilling i thought this was just for large sections/hole dias where pressure on drill/material interface can't be applied by hand drilling?
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Post by Paul (madeye) on Jan 14, 2014 22:20:42 GMT
a rivnut to take an m4 caphead will need a hole to fit it of 6mm min, to tap it will need 3.2mm.
rivnuts can spin too,
obviously its your choice.
My personal opinion would be to avoid them as much as possible and only use them when all other options are exhausted.
But sometimes I even ignore myself....
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Post by kiwicanfly on Jan 14, 2014 23:41:12 GMT
Not sure of the benefits of mag drilling i thought this was just for large sections/hole dias where pressure on drill/material interface can't be applied by hand drilling? Paul was referring to using a suitable drill to combat the forces generated by the the flowdrilling weapon. For the light panels I don't think you need rivnuts because they are so light, tap straight into the tube with M4 and you get around three threads M4 (0.7mm pitch) in a 2mm wall. I would save rivnuts for things that need to be secure or places where the tapping did not work out. Remember, unless you have a "putting on drill" you can always open a hole up to bigger sizes and put rivnuts in later. |
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Post by Paul (madeye) on Jan 15, 2014 8:01:18 GMT
I wont lie to you, tapping out for the floor and all the panels was an absolute pain in the backside.
but if there were 200 fixings I have done so far, with an extra 9mm of material (quick maths, +3mm dia hole x pye)that's 1800mm (linear)of material removed. good for weight saving I suppose.
and I know someone is now going to have a go at the maths too.. lol
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Post by carbonbob on Jan 20, 2014 19:27:43 GMT
I have used riv nuts when fixing to alloy panels and drill and tap 4mm for into chassis worked great
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