Caster and shock angles...am I overthinking this?

[ellis8500]

Keep in mind there is not much of a load on the shock mounts unless the shock bottoms out. The shocks retract and extend in operation; the only load is the resistance of the shock itself. I have two 1/4-20 grade 8 bolts vertical, one horizontal. Each bolt is good for a 4750 lb tensile load so two provide 9,500 lbs tensile strength per side. Total both sides 19,000 lb tensile strength. As I said before, you can lift the car with those mounts.

If you need custom mounts, draw them and send to RPM for a quote. His prices are unbelievably reasonable and his service is the best. If you need some CAD work done, send me a sketch.

Hey 2old2 fast...my youngest brother lives in Ottawa. We grew up in Aurora.

 

[2old2fast]

'Tis a small world , is your litle brother a car guy ???
dave

 

[ellis8500]

Use the 3/16ths wall tube. Spirit, RPM, Cal Customs all use it for a reason. You will want to drill and tap the frame for various things. You might not think so now, but you will for clips, brackets, ground connections. The 1/8th wall is really too thin for #6 and larger screws. Believe me, and just about everyone else here, the frame weight is not a factor in these cars.

 

[fluidfloyd]

As long as the crush tube is flush to the inside walls of the rectangular tube then it will support that tube in compression and all will be good. I prefer to drill through rectangular tubes with a hole the same diameter as the round tube. Then chamfer the round tube ends and countersink the holes in the rectangular tube and weld that "V" section up. sand flush and bolt it together. That way there are no stress risers or notch effect holes where a highly stressed rain can start to crack. In lite loaded rails this is not an issue. Just my two cents worth.

George

 

[2old2fast]

Dated a girl from aurora ,late '60's , used to cruise the street where Bob's big boy was ...good times.... bought the t body that I'm using fom John Hull at bellweather[sp.] in '68 , only took 34 years to complete it ...
dave

 

[ellis8500]

No Dave, my brother is not a car guy. The Big Boy was on North Lake St. [Hwy 31] across from the Gaylords discount store. I worked there in 1966.

 

[Zandoz]

Keep in mind there is not much of a load on the shock mounts unless the shock bottoms out. The shocks retract and extend in operation; the only load is the resistance of the shock itself. I have two 1/4-20 grade 8 bolts vertical, one horizontal. Each bolt is good for a 4750 lb tensile load so two provide 9,500 lbs tensile strength per side. Total both sides 19,000 lb tensile strength. As I said before, you can lift the car with those mounts.

If you need custom mounts, draw them and send to RPM for a quote. His prices are unbelievably reasonable and his service is the best. If you need some CAD work done, send me a sketch.

Hey 2old2 fast...my youngest brother lives in Ottawa. We grew up in Aurora.

Yeah, when you do the math, the 1/4" bolts are sufficient.

I'm hoping to have RPM do the frame, so I'll just add them to the list. Thanks for the CAD offer. I'm a self taught CAD amateur. I played with a DOS version of Autosketch for probably 25 years. I did everything from communication equipment cabinets to 3 complete homes. Two years ago I started laying out this project in detail on the old Autosketch, and a little over a year ago I maxed out the file size capacity. I switched to DraftSight and started the learning curve. Today I've probably got 75% of this project laid out in DraftSight, in varying degrees of detail. As I get a part I replace the original rough guestimates with specific dimensions.

 

[ellis8500]

Looks good. Now stop drawin and start buildin. We want to see a car. Gently remind the Minister of Finance that budgets are somewhat flexible and are always subject to cost-benefit analysis modification.

Draw a custom design shock mount and send the .DXF file to RPM. He can cut the parts, weld and finish. Or, just cut and send you pieces.

 

[T-Test]

My frame will probably end up 2x3 3/16" wall...but I'd actually prefer 1/8" wall as a matter of lightness. Between the short span of the frame rails due to the short wheel base, and the light weight low power engine, the 3/16" wall seems overkill to me <shrug>

I use the 3/16 thick steel and use self threading bolts to hold F-1 style shock brackets to the frame. No problems-- after I went to square stock instead of round stock [s/s].[

 

[Zandoz]

Looks good. Now stop drawin and start buildin. We want to see a car. Gently remind the Minister of Finance that budgets are somewhat flexible and are always subject to cost-benefit analysis modification.

I hear ya...but I really do not want to push my luck. She has been VERY supportive in all this, and frequently has been been more ready to "go for it" than I.

 

[T-Test]

I hear ya...but I really do not want to push my luck. She has been VERY supportive in all this, and frequently has been been more ready to "go for it" than I.

Well I think she's a keeper!!! Helpful, giving, and cooks and clean up after you. What more can a man ask for---Other than a boat!!!

 

[Zandoz]

Well I think she's a keeper!!! Helpful, giving, and cooks and clean up after you. What more can a man ask for---Other than a boat!!!

She's definately a keeper. No boat needed...I'd settle with just a dock...with a comfy chair, sun umbrella, a cooler with drinks, and a radio with the ball game on.

 

[ellis8500]

For a boat ya need water and most of us don't live at the water. For our cars we need roads and we all live at roads. Besides, I keep hearing that boats are even bigger money pits than our cars. Just go price boat parts. Airplane parts are even worse.

 

[2old2fast]

my grandfather was a dentist & overall was considered to be a very bright fellow...I'm not positive of his exact words , but he used to tell me : people lose more money , time , & relationships by a lack of decision than the wrong decision... always made sense to me ....
dave

 

[Zandoz]

Use the 3/16ths wall tube. Spirit, RPM, Cal Customs all use it for a reason. You will want to drill and tap the frame for various things. You might not think so now, but you will for clips, brackets, ground connections. The 1/8th wall is really too thin for #6 and larger screws. Believe me, and just about everyone else here, the frame weight is not a factor in these cars.

I agree...for the typical of these cars frame weight is not an issue. But for my car it will be an issue. Where most have high output V8s, mine will have a little V6 that will probably never be over 150 HP. To make matters worse, carrying me it will be carrying more than the typical bucket occupant. Finally, it will frequently be pulling around 600lbs of powerchair and trailer. It all adds up to every bit of weight I can save will be beneficial.

For fastening things, when necessary I'd use nutserts...I'll be doing that anyway.

If I had the fabrication abilities, I'd be building the frame out of 2x4 extruded aluminum beams. Having said all that, I'll probably end up taking the path of least resistance, and go with whatever the builder of the frame wants.

 

[Zandoz]

my grandfather was a dentist & overall was considered to be a very bright fellow...I'm not positive of his exact words , but he used to tell me : people lose more money , time , & relationships by a lack of decision than the wrong decision... always made sense to me ....
dave

He never met me...the poster boy for Murphy's Law. LOL