Stainless Steel Chassis....
Discussion
After spending ~70 hours on my chassis a few months ago and knowing that it will probably need doing again in a few years I just wondered......
Why are there no aftermarket stainless steel chassis?
Now before you all leap in with 'impossible to weld', 'not strong enough', 'metal fatigue' and 'too expensive' I've thought about this and the only real obstacle is the tooling...
Does anyone know whether TVR still owns the Chimeara tooling, are there other jigs out there?
Just the rambling of a fool perhaps but there must be a market for thrm....
>> Edited by tigertiger on Tuesday 1st November 18:27
Why are there no aftermarket stainless steel chassis?
Now before you all leap in with 'impossible to weld', 'not strong enough', 'metal fatigue' and 'too expensive' I've thought about this and the only real obstacle is the tooling...
Does anyone know whether TVR still owns the Chimeara tooling, are there other jigs out there?
Just the rambling of a fool perhaps but there must be a market for thrm....
>> Edited by tigertiger on Tuesday 1st November 18:27
tigertiger said:
Now before you all leap in with 'impossible to weld', 'not strong enough', 'metal fatigue' and 'too expensive' I've thought about this and the only real obstacle is the tooling...
I think that you've more or less covered it there. Welding, strength of weld and weld fatigue (could be considered to be all the same point) are a problem but could be overcome by a design check and stiffeners/fillets where necessary. As you mentioned weight is not a problem but the cost of the raw material and cutting it is. I think that you have underestimated the cost. Check the price of mild steel tubes and s/s ones - it's a big difference.
It need not be brittle, depends on the grade and treatment.
JR is closest here, the material cost is about 3x that of carbon steels (due to higher energy costs nickel and cromium shortages mainly). However the main costs are due to labour (fabrication and welding) so material cost will not have as big an impact as you would expect.
Of course folks charge a huge premium for stainless because the perception is that is is expensive but for the less exotic grades (303/304) this is not the case and the difference is material cost can be offset largely by not requiring surface treatment.
Just think of the upside.... mind you there will still be folks under there each weekend polishing those tubes...
>> Edited by tigertiger on Tuesday 1st November 18:48
JR is closest here, the material cost is about 3x that of carbon steels (due to higher energy costs nickel and cromium shortages mainly). However the main costs are due to labour (fabrication and welding) so material cost will not have as big an impact as you would expect.
Of course folks charge a huge premium for stainless because the perception is that is is expensive but for the less exotic grades (303/304) this is not the case and the difference is material cost can be offset largely by not requiring surface treatment.
Just think of the upside.... mind you there will still be folks under there each weekend polishing those tubes...
>> Edited by tigertiger on Tuesday 1st November 18:48
No prob in making a stainless steel chassis apart from the cost,takes alot more man hours than mild steel.PW had one on his race Tuscan.
Before people start saying it won't be strong enough,believe me if it is done by a pro it will be fine,i have made a chassis for an off road Landrover had no probs in over 3 years of serious abuse.
The only other down side is salt,it corrodes stainless steel.
>> Edited by stainless_steve on Tuesday 1st November 18:51
Before people start saying it won't be strong enough,believe me if it is done by a pro it will be fine,i have made a chassis for an off road Landrover had no probs in over 3 years of serious abuse.
The only other down side is salt,it corrodes stainless steel.
>> Edited by stainless_steve on Tuesday 1st November 18:51
Thanks Stainless,
Sure it's going to be more expensive but will save money in the long term and last a lot longer. There are stainless grades that perform well in salt spray tests. What did you make your Landy chassis from?
Do you think it would be possible to develop the tooling for a Chimaera?
Sure it's going to be more expensive but will save money in the long term and last a lot longer. There are stainless grades that perform well in salt spray tests. What did you make your Landy chassis from?
Do you think it would be possible to develop the tooling for a Chimaera?
316 has good chloride resistance, doubt that the laqueur would even be required. Polished tube? shssh! Up-sell that as an option....
Still, back to the problem - bet I could find welders as I'm sure you can too, but it's a question of tooling. Anyone ever seen a Chimaera chassis fixture up for sale or rent?
>> Edited by tigertiger on Tuesday 1st November 19:24
Still, back to the problem - bet I could find welders as I'm sure you can too, but it's a question of tooling. Anyone ever seen a Chimaera chassis fixture up for sale or rent?
>> Edited by tigertiger on Tuesday 1st November 19:24
tigertiger said:
Steve,
Perhaps we should take this offline. I'd be interested in exploring the costs and the market. There may be an opportunity here
Tiger
You appear to have covered most stuff that I know of. I guess that due to the difficulty in cutting, aligning and eldind the labour costs may be 3x also giving a £4K to £5K chassis. Whilst this would be excellent value for a Ferrari of similar performance to a Chim would TVR owners be willing to pay?
Godd luck to both of you.
JR said:
You appear to have covered most stuff that I know of. I guess that due to the difficulty in cutting, aligning and eldind the labour costs may be 3x also giving a £4K to £5K chassis. Whilst this would be excellent value for a Ferrari of similar performance to a Chim would TVR owners be willing to pay?
Godd luck to both of you.
That the problem,a new mild steel chassis pro painted is good for 15 years.How much do TVR charge for a new chassis? then you need to add the cost of a pro paint job
Before i switched trades and got into IT i was a welder fabricator and then went on to build prototype cars for Daewoo and have mig and tig welded stainless loads of times...including things like pressure vessels, gas coolers for oil rigs and loads of parts for cars that were tested at Millbrook. The mig welding was just as good as the tig but not as neat and maybe not quite as strong but it would do the job.
Fabrication times of a stainless chassis and a mild steel one would be about the same but the cutting of the tubes would be a bit more time consuming as the stainless would plant any cutting tools slightly quicker.
It would be very easy to make a jig from a decent chassis and i am already measuring up the front lower wishbone on my chim as it needs replacing and i was thinking about this as an option.
Fabrication times of a stainless chassis and a mild steel one would be about the same but the cutting of the tubes would be a bit more time consuming as the stainless would plant any cutting tools slightly quicker.
It would be very easy to make a jig from a decent chassis and i am already measuring up the front lower wishbone on my chim as it needs replacing and i was thinking about this as an option.
Andy,
That's my experience too, albeit from a Engineer / Designer perspective. I recently developed some large 304 stainless structures which were actually cost neutral compared to the original mild steel versions (ok, there was some aggressive purchasing too)
It may be a different story with 316 (if required) I also specced MIG over TIG on cost grounds with the only real compromise being aethetics.
David may be right, but what coating to use and at what price? The chassis members are very exposed unlike most modern mass produced vehicles and will always be succeptible to stone damage.
>> Edited by tigertiger on Tuesday 1st November 21:59
>> Edited by tigertiger on Tuesday 1st November 22:00
That's my experience too, albeit from a Engineer / Designer perspective. I recently developed some large 304 stainless structures which were actually cost neutral compared to the original mild steel versions (ok, there was some aggressive purchasing too)
It may be a different story with 316 (if required) I also specced MIG over TIG on cost grounds with the only real compromise being aethetics.
David may be right, but what coating to use and at what price? The chassis members are very exposed unlike most modern mass produced vehicles and will always be succeptible to stone damage.
>> Edited by tigertiger on Tuesday 1st November 21:59
>> Edited by tigertiger on Tuesday 1st November 22:00
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