|
Post by ssmith764 on Aug 20, 2013 20:49:05 GMT
Thanks for the opinions. I have used a 16mm shaft as per the build guide and it fits quite well. I could use the existing bolt as a grub screw by cutting it down which would avoid the drilling.
|
|
|
Post by daydreamer on Aug 20, 2013 23:34:38 GMT
For the record I have no qualifications on the subject but I won’t let that stop me joining in.
I think drilling that hole is fine, if the original retainer is M8 then go for it, if you’re putting in your own retainer then a hardened M6 might be better.
Thoughts in no particular order.
Where the hole is drilled, the cross sectional area of the bar is larger than the main part of the bar. Assuming a close fit, at the place the hole is drilled the cross sectional area of the bar includes the female receptacle, plus when the hole is filled with a bolt there is no hole. ( not strictly true as the hole would have to be threaded and the bolt threaded in but the material loss is a lot less than if there was no bolt in the hole. Even then the threaded bolt could be considered a fracture in the material and a focal point for stresses. There are so many angles to this that I think it is best to try and keep it simple)
The main stress on the component is a rotating movement, hence the bar is flattened at the point it enters its counterpart. The majority of the stresses are transferred via the flats, particularly the extreme edges, the hole that is causing concern is not on these edges but in the middle where the least stresses are found.
A cautionary note , apart from my not having any relevant expertise , I think a close fit is required between the bar and its counterpart and the bolt should not be carrying any of the rotational stresses. I expect the bolt has two functions, to compress the female counterpart onto the bar such that there is no slack or wobble and to prevent the two parts separating. I believe it is best if rotational stress loads are transferred from the bar to its counterpart via the flats on the bar and not via the bolt.
I think a grub screw will weaken the structure as it will separate the bar from its counterpart introducing wobble and becoming a focus for the rotational stresses.
I await merciless correction and ridicule. Just trying to help. Really enjoying all the builds, keep em coming.
|
|
|
Post by ssmith764 on Aug 21, 2013 7:31:38 GMT
Thanks daydreamer, this all makes sense to me so I will go ahead with the drill. I have studied lots of pictures from other builds as most seem to drill the bar.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Aug 23, 2013 16:15:51 GMT
Mines as per ford design, clamped as when it was installed on the focus. It's also welded around the joint of the clamp to shaft. The shaft is the old metal rod from the steering rack, cut down, forged, and filed to make the correct sized ends.
No chances taken.. If everything else fails, bar the steering, I stand a chance of saving something.
|
|
|
Post by ssmith764 on Sept 1, 2013 17:16:16 GMT
|
|
|
Post by shaggy33 on Sept 1, 2013 17:33:55 GMT
That looks lovely and hope mine is half as good as that! What are you using to hold panels and front grill in place, rivnuts?
|
|
|
Post by BobN on Sept 1, 2013 17:35:36 GMT
That looks very nice. I do like the carbon effect on all the cars.
Bob
|
|
|
Post by shaggy33 on Sept 1, 2013 17:49:23 GMT
It's a shame rtr don't do the carbon pack anymore as that would have been a great option for my build as I have an unhealthy carbon fetish
|
|
|
Post by ssmith764 on Sept 1, 2013 18:10:53 GMT
Hi Shaggy, I am using M4 bolts tapped into the frame
|
|
|
Post by shaggy33 on Sept 1, 2013 18:17:34 GMT
Cheers for info. Tapping into frame scares the life out of me, not sure why but perhaps it's due to too many dodgy attempts at threading and tapping over the years!
|
|
|
Post by ssmith764 on Sept 1, 2013 18:45:38 GMT
Its fine if you use good quality taps. I bought a cheap set which only managed one tap before wearing out - crap from China. I since bought an M4 and M6 set which should be all you need but I bought quality ones. Same goes for drill bits. If you buy British engineers tools you can't go wrong
|
|
|
Post by hightower on Sept 1, 2013 18:48:51 GMT
Yea really nice neat job done there think that's next in my list panels and grill all the time and effort makes it worth while in the end mate.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Sept 1, 2013 18:59:56 GMT
I bought 2 HSS drills, for a 5mm tap from the same supplier.
I've built my rocket.. And so far, all sharp, and un snapped.
I've bent the tap a little, but it's fine now lol.
Spend the money with reputable tool shop, and you'll be fine.
|
|
|
Post by shaggy33 on Sept 1, 2013 19:36:45 GMT
That must be my problem, only ever had cheap crappy Chinese made tap die sets. I'll invest in a decent couple of sizes.
|
|
|
Post by ssmith764 on Sept 18, 2013 17:50:11 GMT
A few more jobs done since the last update. I made a bracket for the throttle pedal to drop it in line with the other pedals I made the bulkhead panel too To fit the panel I pretty much had to remove everything I had already fitted and then refit it all. I have connected up the radiator and the pipes look to fit well without kinks
|
|