LocostUSA.com

Learning how to build Lotus Seven replicas...together!
It is currently April 6, 2020, 12:18 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 373 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9 ... 25  Next
Author Message
PostPosted: September 24, 2014, 10:06 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
Miatav8,MstrASE,A&P,F, I follow you. Ideally I'd love to make the A-arms look like ones off of a BAC Mono, but there are a few issues in doing so, as in my fabrication skills, as well as lack of adjustability in control arm length to tune caster, camber, toe, anti-squat, anti-dive, etc...

More bits and bobs did arrive today:
Attachment:
Some assembly required....jpg
Some assembly required....jpg [ 1.11 MiB | Viewed 2480 times ]

Then the realization of ALL of the rod end spacers to cut sets in. There will be ALOT of spacers to make. :(
I plan on simply cutting 7/8" OD tube, with 1/2" ID to the appropriate heights. (But that still is about 64 spacers to make.)

I have front miata uprights, and rear integra uprights, as well as wheels and tires. The plan is to mock up the front and rear suspension and make measurements accordingly. Then input the measurements into my excel calculator, and then order the appropriate AFCO swaged steel tubes.

I think I will go with steel swaged tubes, as the ductility, higher yeild strength, and weldability of mild steel tubes is much better than 6061 AL. I plan on welding 1/8" thich steel plates at the ends of the swaged tubing and attach the second AFCO tube within the sandwich plate, thus creating an A-arm, which will give me caster and camber adjustment.

Still waiting on the 1.75" OD 4130 tubing, and in the meantime, I'm finishing up fully welding the front/mid sections of the chassis tubes.

I appreciate the welding tips guys:
Attachment:
Dialing in the machine...its getting there.jpg
Dialing in the machine...its getting there.jpg [ 1.34 MiB | Viewed 2480 times ]

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: September 25, 2014, 11:39 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
Gents,

Chassis tube welding continues, and sometimes the welds look pretty good, with a consistent speed of pass, consistent bead height, and good penetration. Other times, not so much. I find that if I briefly preheat the weld with a blow torch, the amount of splatter is reduced, and the height of the bead is reduced, and the overall time of completing the weld decreases, (Which is great because I consume less sheilding gas.)

Nevertheless, below are the gory images of my welding. Any constructive criticisms to help me improve are most certainly welcome.
Attachment:
K3 member to Main roll hoop weld.jpg
K3 member to Main roll hoop weld.jpg [ 811.76 KiB | Viewed 2443 times ]

Note the coloration from preheating and welding. I'm fairly confident penetration is good, but aesthetics...not so much.

Often times I am finding if the metal is not uniformly heated prior to starting the bead, the height of the bead will decrease as the portion of metal upon approach will be building a weld at a higher temperature than the section previous:
Attachment:
decrease in height of convex bead height as heat transfer increases during weld.jpg
decrease in height of convex bead height as heat transfer increases during weld.jpg [ 818.4 KiB | Viewed 2443 times ]

Also, the dreaded crater is sometimes back, sometimes not.

Due to surface differences, a double bead was needed:
Attachment:
double weld rearward of main roll hoop to engine bay.jpg
double weld rearward of main roll hoop to engine bay.jpg [ 1.05 MiB | Viewed 2443 times ]

Not exactly a 10lb spool of wire used up in this weld...but close.

And for the section which sustained a bit of burn through:
Attachment:
A little burn through on front end assembly members.jpg
A little burn through on front end assembly members.jpg [ 1.26 MiB | Viewed 2443 times ]

Perhaps no preheating was needed for this one. Also welding to edges together in a vertical position with a horizontal pass was challenging. I may just reshape the edge, and call it a day.

Also, the 4130 tubing is slated to arrive soon, and I'll see if I can make progress on that this weekend. From what I have gathered, MIG welding 4130 is challenging, and I indeed intend on taking my time. Has anyone here had any experience MIG welding 4130? (1.75" OD round tube 0.095" wall). I understand I will need to preheat considerably with a blow torch, as well as gradually cool the metal post weld--perhaps use a heat gun?

This rear chassis engine basket and X-brace will be 4130 and welded to the mild 1020 of the main roll hoop. Are there any pressing concerns which I should be wary of at the junction of 4130 and 1020?

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: September 26, 2014, 7:18 am 
Offline

Joined: August 12, 2012, 6:38 pm
Posts: 1935
Location: worcester county, Massachsetts
LateralScience wrote:
. I find that if I briefly preheat the weld with a blow torch, the amount of splatter is reduced, and the height of the bead is reduced, and the overall time of completing the weld decreases...


lateral, ahhh yes, you've discovered a key technique.

duringthe B-3 build - especially during the MOD 2 control arm fabrication in march of '13 - that preheating the steel to red-hot made it flow "like buttah" and I got much better penetration and fill flow.

it also seemed to me that round tube acted as a greater heat sink than plate or square tube and was harder to initially heat when striking the first spark. some of my crappiest welds were on round tubing, made cold, even thought he wall thickness was within the weldable range of my Northern Tool MIG 135

preheating solved all that. when I redesigned the front control arms using a variety of .156, .125, .083 tubing and .188 thick plate, after bolting in to the jig, and fired up the oxy-acetylene torch, heated things red hot, and then struck the spark.

in my view, as far as preheating goes, hotter is better.

your welds look fine BTW. as I am so fond of saying, "I'd crash that." ;-)

EDIT: also BTW, get the mods to move this thread into the Non-Traditional Build Logs. you're actually building something heayah, not just droning on about some crazy idear. ;-)

_________________
The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941

The Jag Special Build Log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=19012


Top
 Profile  
Reply with quote  
PostPosted: September 26, 2014, 10:37 pm 
Offline
We are Slotus!
User avatar

Joined: October 6, 2009, 9:29 am
Posts: 7687
Location: Tallahassee, FL (The Center of the Known Universe)
Quote:
you're actually building something heayah, not just droning on about some crazy idear.

Rob, speak English, dammit!!! :mrgreen:
He's correct though, the welds look pretty good. Keep after it!
:cheers:
JDK

_________________
JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom


Top
 Profile  
Reply with quote  
PostPosted: September 26, 2014, 10:41 pm 
Offline
User avatar

Joined: April 19, 2012, 9:43 pm
Posts: 419
Location: Colorado
With the 4130, preheat to a dark cherry red glow then strike up the weld. When done, wrap it with bat insulation (paper backing out, or better yet removed) or similiar and let it cool. Joining 4130 to 1020 depends upon your wire. What are you using?

EDIT: You're gonna have to watch for warping. It's gonna move.


Top
 Profile  
Reply with quote  
PostPosted: September 27, 2014, 10:25 am 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
I appreciate the help guys. For doing the full welds on 4130 I'll be using ER80s2 MIG wire. At the moment I'm just cutting and mocking up the engine basket tubes and tacking them in place with ER70s6 wire. I'll pickup some bat insulation and preheat/slow cool as suggested. It's crossed my mind to heat treat and stress relieve the entire chassis once I'm done, but I haven't priced out what that would cost.

Also, 37.4 lbs for 24ft of 1.75" OD 0.95" wall 4130. A pretty BIG difference compared to the 96 lbs of stamped sheet metal of the OEM Acura front subframe. Plus my rear basket will be triangulated and gussetted, and much stiffer than the OEM subframe.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: September 27, 2014, 12:58 pm 
Offline
User avatar

Joined: April 19, 2012, 9:43 pm
Posts: 419
Location: Colorado
No one heat treats and there is a specific reason why: The frame will warp when treated. You might get lucky and have it warp in a way that does not make the frame useless, but it could end up un-useable. With properly designed welds on thin walled (relative to diameter) DOM do not see the gains you would think from heat treating. The practical strength changes only a little.


Top
 Profile  
Reply with quote  
PostPosted: September 27, 2014, 1:59 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
Interesting. I recall the 4340 sheet metal boxed uprights were heat treated for our 2011 FSAE car. But there was a 1" thick steel plate used as a jig to retain locations of the pickup points. This perhaps was another application than my 4130 rear engine basket. This is most likely not a feasible option due to cost.

With regards to the TYPE of filler metal to use on 4130 with MIG, I'm reading that ER70s2 (mild steel) is actually more appropriate to use than ER80s6 (high carbon), if the chassis is NOT to be heat treated.

From the American Welding Society:
http://www.aws.org/wj/apr03/AWfeature.html/

-----------
What about Welding 4130?
In the mid 1970s, while managing an R&D group for a welding filler metals manufacturer, I received a phone call from a dragster chassis builder. The company wanted to weld 4130 tubing and needed a filler metal recommendation. After careful review of the requirements and desired welding practices, the solution was defined. The company was welding 4130 normalized tubing. It would not be heat-treated after welding, and preheat was not desirable. Most of the weld joints were intersecting tubes that required fillet welds.

Filler Metal Choice
The main objective was to produce porosity- and crack-free weld deposits. The best filler material to use was a low-carbon alloy, AWS ER70S-2. This welding alloy has a very low carbon content, nominally 0.06, which can handle dilution into the relatively high (in terms of weld metal) 0.30 carbon in the 4130. The resulting diluted weld deposit has a tensile strength of approximately 590 to 620 MPa (85,000 to 90,000 lb/in.2) The actual strength will depend on the amount of dilution with the 4130, weld bead size, and material thickness. This is usually an under match for the 4130 tubing, which could have 760 to 800 MPa (100,000 to 115,000 lb/in.2) tensile strength, depending on how the material was processed. However, if extra joint strength is required, a slightly larger fillet size or gussets can be employed. In addition, this welding wire contains small amounts of aluminum, titanium, and zirconium. Although these elements were initially added to handle welding over mill scale, they also contribute to a less fluid weld pool. The benefit to the welder is easier out-of-position welding. Note: It is recommended all welding on 4130 be performed on ground surfaces free of oil or grease.

Several years after making this recommendation, when looking at a catalog from the dragster chassis manufacturer, it was interesting to note it advertising its use of the ER70S-2 filler metal for their 4130 welding. In fact, offering it for sale for those customers purchasing frame parts and doing their own welding!

The Internet was searched to see what current recommendations were being made for joining 4130 tubing. Several hundred sites were found that recommend the ER70S-2 welding wire alloy. It was the predominant recommendation. Typical of the Internet, however, there were many improper descriptions of why this alloy should be used and several incorrect recommendations.

Go for Higher Strength
If a higher strength weld is required for perhaps a butt-joint weld that cannot be reinforced, strengthened with a gusset, or put in a less critically stressed area, there are several possible solutions. The use of AWS ER80S-D2, which contains 0.50 moly, will provide a weld deposit with higher strength. When diluted into the 4130 base material, a weld tensile level of 760 to 800 MPa (110,000 to 115,000 lb/in.2) can be achieved. If this higher strength welding wire is employed, a minimum preheat of 65¡C (150¡F) is recommended. It is also possible to use an AWS ER312 stainless steel welding wire. Weld strength can increase to a level slightly higher than with AWS ER80S-D2.

Generally, the use of this high chrome stainless alloy is only needed when welding stainless to steel. Do not use an austenitic stainless steel such as an ER308L, which is, unfortunately, sometimes recommended. Diluting this or similar austenitic stainless alloys with 4130 can lead to cracks. Also, consider that providing a higher strength weld deposit cannot compensate for the reduction in strength that will most likely occur in the base metal immediately next to the weld deposit. To achieve the higher strength, the base metal was heat-treated, reducing the weld heat-affected zone area hardness.

If the part is heat-treated after welding to achieve very high strength, a matching chemistry filler metal to the 4130 must be employed. Because of the relatively high carbon content, a minimum of 200¡C, (400¡F) preheat and very slow cooling after welding should be used to avoid cracking. After welding, the part can be heated to 870¡C (1600¡F), quenched in oil or water then tempered back to 370¡C (700¡F). This might be considered a complex cycle, but it will result in a tensile strength of approximately 1380 MPa (200,000 lb/in.2). Since the weld is the same chemistry as the base metal, it and the heat-affected zone will have properties similar to the base metal when heat-treated. All critical welds of this type should be inspected for internal soundness to assure they are free from cracks.

Closing Advice
When welding 4130 chrome moly in the normalized condition, AWS ER70S-2 filler metal, with its low carbon content; is the proper choice. If the part is to be heat-treated after welding, then a filler metal matching the 4130 chemistry should be employed. This requires preheat and special precautions to avoid cracking.

JERRY UTTRACHI has 38 years' experience in the welding industry and is currently a consultant for ESAB Welding and Cutting Products. Email guttrachi@aol.com

-----------------------------

From Past Locost discussions:
http://locostusa.com/forums/viewtopic.php?t=3877/

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: September 27, 2014, 11:39 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
Not too much progress today, as my company dinner came up.

The bare block and transmission is placed appropriately relative to chassis. The only thing not representative of installation orientation is the angle of the axles.

I cut the left and right primary booms to length, fishmouthed the ends, and tacked them 90 degrees from the plane of the main roll hoop:
Attachment:
Right boom member connecting main roll hoop to rear bulk head.jpg
Right boom member connecting main roll hoop to rear bulk head.jpg [ 1.01 MiB | Viewed 2303 times ]


Mind you, I do not have a tube notcher, nor a drill press, so I am notching the tube ends by hand, and hand fitting them by gradually removing material where appropriate:
Attachment:
say awe.jpg
say awe.jpg [ 887.86 KiB | Viewed 2303 times ]


I am most certainly not the best at fishmouthing tubes, and creating even contact along the mouthed circumference could be improved. Any suggestions?
Attachment:
Upper rear engine cradle member to right side primary boom.jpg
Upper rear engine cradle member to right side primary boom.jpg [ 607.16 KiB | Viewed 2303 times ]

Attachment:
Detail of fishmouth joint2.jpg
Detail of fishmouth joint2.jpg [ 483.51 KiB | Viewed 2303 times ]


Joining the end of the left boom to the rear cradle member and left triangulation member:
Attachment:
Detail of fitment of 1.75 inch OD fishmouth tubes joining at end of engine cradle.jpg
Detail of fitment of 1.75 inch OD fishmouth tubes joining at end of engine cradle.jpg [ 1 MiB | Viewed 2303 times ]


From what I recall from Carroll Smiths' books, I believe it was Engineer to Win, the centerline of all tubes should intersect at the same node. Cutting an appropriately shaped fishmouth on the triangulation member securing the top of the main roll hoop is challenging, as this notch is "out of plane." Any suggestions in improving this?

Mocking up tubes of the rear engine cradle:
Attachment:
mockup of rear members creating engine cradle.jpg
mockup of rear members creating engine cradle.jpg [ 1.21 MiB | Viewed 2303 times ]

Trailing LCA inboard points will pickup on the lower upsidedown trapezoid corners. Also, a smaller tube X will be placed in the lower trapezoid creating 4 triangles. The rear trapezoid will pickup the rear engine mount, toe links, and trailing upper control arms.

The bottom of the trapezoid will have a BOLT-ON X-brace under the belly of the engine cradle connecting it to the triangulation members of the main roll hoop. (Look past wood blocks below) This X-brace MUST be bolt on, since engine installation is from the bottom.
Attachment:
rear trapezoid member to join triangulation member at the bottom of the main roll hoop via 4-bolt X-brace.jpg
rear trapezoid member to join triangulation member at the bottom of the main roll hoop via 4-bolt X-brace.jpg [ 927.43 KiB | Viewed 2303 times ]


Upon hard acceleration, the leading rear LCA's will be inducing a compressive load at the very bottom of the triangulation members joining the main roll hoop. The stresses from this load will be diverted through multiple tubes both in and out of the plane of that force vector.

Those members include:
-Left and right lateral members at the bottom of the main roll hoop. (Loaded in bending)
-Triangulation floor members crossing the floor of the cabin diagonally joining at the leading end of the Locost7 Book Chassis members B1 and B2 meeting nodes of left and right uprights "H". (Loaded in compression)
-2 members from the lower belly X-brace under the engine cradle. (Loaded in tension)
-Triangulation members of main roll hoop (Loaded in bending)

I'm fairly confident with multiple members carrying the load from an abrupt impulse from a clutch dump with R-comps, this configuration should be more than sufficient. (Especially with the higher yield strength of 4130 in 1.75" OD tubing.) No, I don't have an FEA model to quantify the Factor of Safety--so sue me.

One concern my wife has, is with all of this triangulation and gussetting of multiple tubes to cradle and protect the engine, the engine should be safe and intact if I flip the car. The driver, maybe not so much... as there currently are NO plans for a roof, A-pillar, doors, or windshield. But, it has crossed my mind that this thing could kill me if I flipped it.

Perhaps I'm just crazy, as I want to preserve the mid/front end to look like a showroom Caterham R500 or 620R.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: September 28, 2014, 7:24 am 
Online
Automotive Encyclopedia
User avatar

Joined: December 22, 2006, 2:05 pm
Posts: 6587
A tube marking gauge can be made with a piece of cardboard about 4 inches wide parallel to the corrugations, gas welding rods or wire cut to about 6 inches to insert through the corrugations, and tape over the ends of the cardboard to create friction on the rods/wires.
Essentially a profile gauge. However, a tube that can be held to the other node and just short of the desired length is required to set the gauge. Then the gauge is transferred to the tube to be used without disturbing the rods and the tube is marked for cutting.

Steve "born to be square"

For street use, consider frontal impacts with other vehicles and deer, since the animal or bumper will most likely be coming over the bonnet.

_________________
MV8

https://www.youtube.com/watch?v=Om3C1Ep ... D3E18BB447


Top
 Profile  
Reply with quote  
PostPosted: September 28, 2014, 11:05 am 
Offline

Joined: August 12, 2012, 6:38 pm
Posts: 1935
Location: worcester county, Massachsetts
Yeah, "Caveman simple", sure...

OMG we all laughed at that one ;-)

RE: the car killing you. you're at arguably greater risk in your proddie doorslammer droning along to work. as long as your roll bar passes the "broomstick test" you'll be fine.

_________________
The B-3 build log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=13941

The Jag Special Build Log: http://www.locostusa.com/forums/viewtopic.php?f=36&t=19012


Top
 Profile  
Reply with quote  
PostPosted: September 28, 2014, 12:50 pm 
Offline
The voice of reason
User avatar

Joined: January 10, 2008, 4:47 pm
Posts: 7652
Location: Massachusetts
Look up "tube miter" on google. There are programs for MAC and PC that will print a nice template for any angle and tube thickness. The PC version I found was better because it drew different lines for the inside diameter and outside diameter of the tube.

It seems the intersection of two tubes must be a plane, because when all is said and done the cuts are straight... Think cutting the end of the tube to make a spear with two points.

_________________
Marcus Barrow - Car9 an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.


Top
 Profile  
Reply with quote  
PostPosted: September 28, 2014, 1:32 pm 
Offline
User avatar

Joined: October 23, 2010, 2:40 am
Posts: 1177
horizenjob wrote:
Look up "tube miter" on google. There are programs for MAC and PC that will print a nice template for any angle and tube thickness. The PC version I found was better because it drew different lines for the inside diameter and outside diameter of the tube
+1 on Marcus' suggestion. Several free software packages out there.

Once generated, you can size the template accurately using something like Photoshop and then print it on 4x6 photo stock. That makes a nice template when trimmed and wrapped around the tube, complete with inside and outside trim angles and inflection points. Mark the tube using the template and then slide the template back for an added visual guide. Rough cut with a cut off wheel and trim up with a die grinder and large burr. With a little practice it is surprising how fast you can cut a really accurate fish mouth.

_________________
Cheers, Tom

My Car9 build: viewtopic.php?f=35&t=14613
"It's the construction of the car-the sheer lunacy and joy of making diverse parts come together and work as one-that counts."

Ultima Spyder, Northstar 4.0, Porsche G50/52


Top
 Profile  
Reply with quote  
PostPosted: September 28, 2014, 9:06 pm 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
Thanks for help Gents!

horizonjob, the tube miter program was an excellent suggestion! I've downloaded the program, and input my values accordingly.

robvious, my initial plan was to use a miata front subframe, and the integra rear subframe, join the two together in holy matrimony via box tubes and keep it caveman simple, I swear! Sourcing a miata subframe and suspension arms at a reasonable price became a challenge, hence the change to a middy book chassis.

Progress on the build got sidelined today, as maintenance work was required on my G35. Nothing major, just a AC condenser fan replacement, oil change, headlight bulb install, and visit to the state inspector. Nevertheless, this was enough to tire me out for the day. I'm not as strong as I was in my twenties, and my hands are developing vibration fatigue and numbness (known as vibration white finger VWF) from the angle grinder, miter saw, dremel, pneumatic die grinder, and hand drill. My entire right arm went numb a few days ago. Vibration fatigue can cause permanent nerve damage if appropriate measures are not taken.
CDC:
http://www.cdc.gov/niosh/docs/83-110/

I can visualize in my mind the fabrication work that needs to be completed, the problems is my hands just can't keep up, as I'm getting old.

And I've still got to install new pads and rotors on the wifes' stationwagon, and change the oil on the miata. I suppose maintenance on the daily drivers takes precedence over playing with my toy car, as the daily drivers are needed to get to work.

I think I may be fooling myself to think I can drive my middy Locost7 to the first autocross next March, if I keep working on the car EVERY day. No matter how small the task--just keep working on it.

A finished car is merely a culmination of millions of completed small tasks.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
PostPosted: September 29, 2014, 1:03 am 
Offline
User avatar

Joined: August 18, 2014, 11:20 pm
Posts: 185
Location: San Antonio, Texas
While I have a relatively solid plan for the front and rear chassis tubes, a few things are up in the air:

-Front upper control arm design
-Front lower control arm design
-Front pushrod pickup point
-Rear shock pickup point on chassis and upright/LCA

From the looks of it, Caterham places the trailing front UCA ~90 degrees from the chassis centerline, and angles the leading front upper control arm forward.
Attachment:
Caterham suspension.jpg
Caterham suspension.jpg [ 117.56 KiB | Viewed 2217 times ]

This places the LCA threaded shank in tension when cornering and in bending when braking. But this arrangement would allow for easy camber adjustment. I was thinking of following suit, and use rod ends instead. (No I don't think using two rod ends would be lighter than a single ball joint, in fact two 5/8-18 rod ends would likely be heavier.

For the front LCA, I was thinking of welding a steel plate to AFCO swaged tubes. Has anyone done this before? There is a dramatic taper approaching each end, which is where I would intend on welding the leading arm, and pushrod pickup points. Such an arrangement would allow for easy caster and camber. (I don't think King Pin Inclination would be adjustable, as that I believe is dictated by the upright.)
Attachment:
AFCO swahed tube.png
AFCO swahed tube.png [ 85.47 KiB | Viewed 2217 times ]

I assume I can simply grind off the zinc coating and weld to the mild steel? AFCO does make a chromoly tube, which looks to not be swaged, and simply finished with weld-in threaded nuts:
Attachment:
AFCO chromoly tube.jpg
AFCO chromoly tube.jpg [ 13.08 KiB | Viewed 2217 times ]


Seeing as the cost is more to weld this together myself from raw materials, than to buy it premade from AFCO, as well as I trust AFCO's welding over mine for control arms, I think this is a reasonable route to take.

I would love to have single tubes going from the chassis to upright with ALL rod ends captured in double shear, and nearly NO threads in bending, similar to this:
Attachment:
BAC mono.JPG
BAC mono.JPG [ 203.83 KiB | Viewed 2217 times ]

Attachment:
BAC Mono2.JPG
BAC Mono2.JPG [ 195.65 KiB | Viewed 2217 times ]


With regards to the rear shock pickup point, I intend on having loads transmitted to the rearmost engine cradle node, which will be supported by 4 tubes. In essence, it would try to copy an IMSA Toyota Celica rear end:
Attachment:
imsa-celica-3.jpg
imsa-celica-3.jpg [ 127.25 KiB | Viewed 2217 times ]

Attachment:
imsa-celica-14.jpg
imsa-celica-14.jpg [ 132.71 KiB | Viewed 2217 times ]


More or less along the same lines as the rear Kimini shock point:
Attachment:
Kimini.JPG
Kimini.JPG [ 151.49 KiB | Viewed 2217 times ]


It appears to be a common pickup point for rear shocks, as seen on the Ford RS200:
Attachment:
rs200.jpg
rs200.jpg [ 139.38 KiB | Viewed 2217 times ]


If anyone has any experience welding on ACFO swaged tubes (or their chomoly tubes without the knurling), I'd be interested to see how that went.

_________________
There is no such thing as mechanical failure, only a lack of attention to detail.


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 373 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9 ... 25  Next

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: Miatav8,MstrASE,A&P,F and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
POWERED_BY