Chassis Out-Riggers
Discussion
In all your plans to modify your spyder you are not thinking of cutting them off....Are you????
If they are the same as the canam/gtr they are part of the chassis and form the triangulation which is the strength of the chassis. Without them you might as well strap an RS4 to a banana!!!!!!!!!!!!!!!!!!!!!!!
The spyders side impact is already weak(as per my mates prototype crash) as this hit the tree at approx 25 mph and bent the thing arround and if anyone had been in the passenger seat they would have been killed.... if you want to look at modifying the side id speak with the facctory and if anything strengthen it more rather than think of removing!!!!!!!
i havent owned a spyder so cant comment professionally but understand chassis design and its strengths and weaknesses..
If they are the same as the canam/gtr they are part of the chassis and form the triangulation which is the strength of the chassis. Without them you might as well strap an RS4 to a banana!!!!!!!!!!!!!!!!!!!!!!!
The spyders side impact is already weak(as per my mates prototype crash) as this hit the tree at approx 25 mph and bent the thing arround and if anyone had been in the passenger seat they would have been killed.... if you want to look at modifying the side id speak with the facctory and if anything strengthen it more rather than think of removing!!!!!!!
i havent owned a spyder so cant comment professionally but understand chassis design and its strengths and weaknesses..
One of the reasons I bought an Ultima in the first place was the quality of the chassis work. Compared to a TVR the welding was from a different (better!) planet. I was not disappointed with my chassis when purchased, nor the quality of my recent, extensive repair. As Paul says, perhaps you have a botched repair job there.
The only thought I have is that you are assuming the tubes are welded into place one at a time but I suspect all the tubes are cut and inserted into a jig. When all the parts are in place a weld is run around all the exposed joints. As a result some edges are now inside and not welded.
Would this fit what you are seeing?
Steve
Would this fit what you are seeing?
Steve
If I understand what you are describing correctly, you have removed a seam welded joint (the combined outrigger/chassis member) the outrigger formerly having bridged and has now exposed a tack welded joint?
In doing this you have removed the sum of the total joint and hence the intended strength/load ability of the original area.
As Steve has pointed out when a chassis is constructed, to remain reasonably cost effective and straight, initial bits of it may be tack welded as a formed shape to be later included as a structure, with ajoining parts at tangents etc, fully seam welded to it.
So, basically if you take a 30mm tube, vee cut it, bent it at an angle of offset say 15 -20 degrees, tack welded it and then later bridge the tack welded joint with a seam welded addition it will actually be stronger than the sole original member being seam welded. (as the total area of weld and loadspread for the combined two is greater than the origianl single member joint).
Its would be fair to say this is slightly less stiff than seam welding every joint before and after combining the parts for final assembly on the jig but you then make whole structure solid and the complex jointed areas of the chassis as potential brittle/weak spots. Also every seam welded member would need an individual jig to avoid possible distortion!
In doing this you have removed the sum of the total joint and hence the intended strength/load ability of the original area.
As Steve has pointed out when a chassis is constructed, to remain reasonably cost effective and straight, initial bits of it may be tack welded as a formed shape to be later included as a structure, with ajoining parts at tangents etc, fully seam welded to it.
So, basically if you take a 30mm tube, vee cut it, bent it at an angle of offset say 15 -20 degrees, tack welded it and then later bridge the tack welded joint with a seam welded addition it will actually be stronger than the sole original member being seam welded. (as the total area of weld and loadspread for the combined two is greater than the origianl single member joint).
Its would be fair to say this is slightly less stiff than seam welding every joint before and after combining the parts for final assembly on the jig but you then make whole structure solid and the complex jointed areas of the chassis as potential brittle/weak spots. Also every seam welded member would need an individual jig to avoid possible distortion!
not seeing photos of the joint is possibly the problem, but i always understood at areas where tubes all join the initial weld is never continuous seam weld so to allow for expansion/contraction (welding generates a lot of heat)and if a solid weld it would crack with stress... the bracing however was a continuous weld.
(a recent article i read stated the works metro 6R4 cars were spot welded not seam welded but spot welded 4 times as often as they felt seam welding wasnt that much better and stronger, the only dissadvantage was in an accident the spot welding broke but a seam wouldnt??
(a recent article i read stated the works metro 6R4 cars were spot welded not seam welded but spot welded 4 times as often as they felt seam welding wasnt that much better and stronger, the only dissadvantage was in an accident the spot welding broke but a seam wouldnt??
You could be correct... as I said in my second post after making the 'discovery' - it's perhaps just the 'design'. Who know? Only the factory could say... and I guess the first thing they would say is why the bloody hell did you cut the chassis out-riggers off! 
Still... I'll be (psychologically) happier knowing that all the chassis members were 'fully' connected. The additional triangulation / bracing I'm working on will make me even happier... hopefully!
Roll on spring... I'll either unveil something half decent, or a complete disaster! Bring it on I say!
Still... I'll be (psychologically) happier knowing that all the chassis members were 'fully' connected. The additional triangulation / bracing I'm working on will make me even happier... hopefully!
Roll on spring... I'll either unveil something half decent, or a complete disaster! Bring it on I say!
Scotty-Boy said:
Well... bit the bullet and done it - and boy am I glad I did!
The cutting / grinding involved exposed that there was a LOT to be desired about the quality of welds. NOT on the out-riggers (couldn't care less about them), but on some of the stressed chassis members themselves!
I assumed that the round-tube upper chassis rails to the rear were 'shaped'. Oh no they're not - the (ever so slight) angle changes are achieved by using separate tubing. Some of the 'gaps' between said rails were absolutely shocking! One was basically 'tack-welded' at 2 points on the inner side and completely 'open' at the other side. The gap was 3mm! Not just my opinion - the engineer I'm using to add to the bracing (and now put all this right) also couldn't believe what he was seeing!
I appreciate that it's a Spyder, so a little older and further back down the development line, but I've seen 7-style home builds by guys with (very) limited ability with better welding!
Any chance of posting pics of what you found?The cutting / grinding involved exposed that there was a LOT to be desired about the quality of welds. NOT on the out-riggers (couldn't care less about them), but on some of the stressed chassis members themselves!
I assumed that the round-tube upper chassis rails to the rear were 'shaped'. Oh no they're not - the (ever so slight) angle changes are achieved by using separate tubing. Some of the 'gaps' between said rails were absolutely shocking! One was basically 'tack-welded' at 2 points on the inner side and completely 'open' at the other side. The gap was 3mm! Not just my opinion - the engineer I'm using to add to the bracing (and now put all this right) also couldn't believe what he was seeing!
I appreciate that it's a Spyder, so a little older and further back down the development line, but I've seen 7-style home builds by guys with (very) limited ability with better welding!
I have to say, whenever 'engineers' or whatever get involved, they feel it's their solemn duty to find fault in anything they touch saying "Oh my, God, I would never have done it like that - what you want to do is...." which generally translates to "I really know what I'm talking about, now give me a bunch of cash and I'll fix it".
Now I'm not saying this is the case in this instance, but if I had a pound for everytime I've seen/heard it (especially when I was racing), I'd have a McLaren F1 by now
As I said, post some pics so we can try to fathom what the score is?
I've no case to get touchy Stig - I'm not a chassis specialist (and nor is my engineer - he's just a damn good welder who will put into place the chassis braces recommended by a chassis specialist!).
I was just surprised to see 'gaps' and the engineer being a 'welder-extraordinaire' was scratching his head as to why the weld wasn't complete before fitting the out-rigger section around it.
As I said earlier - that's maybe just the way the chassis is 'designed' to work! I've read Ultima / Ted's history and I'm guessing they know exactly what they're doing!
I was just surprised to see 'gaps' and the engineer being a 'welder-extraordinaire' was scratching his head as to why the weld wasn't complete before fitting the out-rigger section around it.
As I said earlier - that's maybe just the way the chassis is 'designed' to work! I've read Ultima / Ted's history and I'm guessing they know exactly what they're doing!
Personaly cant believe you cut them off...... Be very carful as the chassis has alot of strenght added by those out riggers, you will need to strenghten the front and rear bulkheads plains of the chassis now as you have little tranulation between them...... We added more Diagnals in the outriggers which helped continue the Load Paths down the chassis, and has over double the rigidity because of just that.... Just be carfull bud, last thing you want is to lower the twist rigidity trust me, just park with one wheel on the curb and you should get one wheel in the air, but I never did in my old GTR and the doors then didn't close....
I know, I know! These things are often a 
I've been on the kit-car scene for a while (first Ultima product though) and I just tend to 'do' these things from time to time... sometimes it works... sometimes I have to buy a new chassis, or abandon the plan altogether. I got the unfinished Spyder kit I'm working on at a good price, so I'm not (financially) scared of fiddling with it!
It's hard to explain what I'm trying to achieve here... and I'm no good at drawing! I have a set plan in mind for both chassis and body which I'll just have to get on with and let you all judge when it's finished.
I know many see this sort of thing as sacrilege (the Caterham lads used to continually 'cyber-shake' their heads at me when I played with my 7 - some of the things I did worked, others didn't). I enjoy the challenge of the build as much as driving the thing!
I tried taking a couple of snaps, but I couldn't get anything clear enough. The chassis is off for shot-blasting next week prior to going to the engineers, so will try again when it's out in daylight. Having said that, the more I look at the gap - the more it looks like 'design' rather than fault (even the engineers conceded this may be the case... and they don't do that often!).
PS - Ted... if it turns into a bag of poo - then I promise not to register it as an Ultima.
I've been on the kit-car scene for a while (first Ultima product though) and I just tend to 'do' these things from time to time... sometimes it works... sometimes I have to buy a new chassis, or abandon the plan altogether. I got the unfinished Spyder kit I'm working on at a good price, so I'm not (financially) scared of fiddling with it!
It's hard to explain what I'm trying to achieve here... and I'm no good at drawing! I have a set plan in mind for both chassis and body which I'll just have to get on with and let you all judge when it's finished.
I know many see this sort of thing as sacrilege (the Caterham lads used to continually 'cyber-shake' their heads at me when I played with my 7 - some of the things I did worked, others didn't). I enjoy the challenge of the build as much as driving the thing!
I tried taking a couple of snaps, but I couldn't get anything clear enough. The chassis is off for shot-blasting next week prior to going to the engineers, so will try again when it's out in daylight. Having said that, the more I look at the gap - the more it looks like 'design' rather than fault (even the engineers conceded this may be the case... and they don't do that often!).
PS - Ted... if it turns into a bag of poo - then I promise not to register it as an Ultima.
Edited by Scotty-Boy on Sunday 19th October 20:52
I know we all like to try and improve things when we at the stage your at, it's always nice to personalise any car and part of the reason you build a Ultima is to stand out....
So I know where your coming from, thing that's puzzling me is if you going to remove them because you want to alter the body then that's going to be thinner in the middle ?? what you turning it into a Lotus 7 ??? They do support the centre section of the original Body...... Intrigued ...
So I know where your coming from, thing that's puzzling me is if you going to remove them because you want to alter the body then that's going to be thinner in the middle ?? what you turning it into a Lotus 7 ??? They do support the centre section of the original Body...... Intrigued ...
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