67 replies to this topic

[DirtModeler]

There's lots of different ways to skin a cat.

When i'm doing brass work, i use a magnetic jig.

I usually torch solder my frames, and it works well. I print out the plans, and use extremely strong rare earth magnets to hold everything down to a steel base plate.



Full Article I wrote on the subject:
http://www.dirtmodeler.com/?p=412

Edited by DirtModeler, 29 November 2012 - 12:42 PM.

[RAT-T]

HI GUYS,

WHEN BUILDING A TUBE CHASSIS FOR A PRO MOD, PRO SPORTSMAN ETC, DOES THE FLOOR TIN GO IN FROM THE TOP, OR FROM THE BOTTOM UP? OR IS IT PERSONAL PREFERENCE?

[TedsModeling]

This thread was really smoking.  What happened?  You guys get burned out?  After reading all of the techniques described, I feel like my head is STILL spinning.  What a wealth of information here!

[Prostreet]

HI GUYS,

WHEN BUILDING A TUBE CHASSIS FOR A PRO MOD, PRO SPORTSMAN ETC, DOES THE FLOOR TIN GO IN FROM THE TOP, OR FROM THE BOTTOM UP? OR IS IT PERSONAL PREFERENCE?

 

 

They go to the bottom, I know on Promods and i assume most pro classes the floor on the drivers side needs to be steel welded directly to the chassis. The center and passenger side can be carbon.

 

Goto this link lots of great reference pictures.

 

http://www.facebook....k=photos_stream

[RAT-T]

THANKS JOE,
I'LL CHECK OUT THEIR WEBSITE AS MY FACEBOOK PAGE IS NOT WORKING

[TedsModeling]

C'mon Joe, with all of that information at hand, how am I going to give the excuse that I didn't know any better?

What a load of information there! I go to their site and even Liked them on Facebook, but I haven't seen that many photos at a time.

Thanks, Joe

Edited by TedsModeling, 08 January 2013 - 04:07 AM.

[Prostreet]

C'mon Joe, with all of that information at hand, how am I going to give the excuse that I didn't know any better?

What a load of information there! I go to their site and even Liked them on Facebook, but I haven't seen that many photos at a time.

Thanks, Joe

No problem ,  You Have a PM

[RAT-T]

JOE, DO YOU PIN YOUR JOINTS WITH ANYTHING?

 

 

MIKE, GREAT HOW-TO STUFF ON YOUR SITE

[Prostreet]

Tom, I did not pin anything on my chassis. I used Tenax7r and CA to build my chassis, It seems plenty strong. Pinning it wouldn't hurt anything though, would make it alot stronger but isn't necessary.

[RAT-T]

OK THANKS AGAIN JOE

[comp1839]

i have a question for you guys. how much does it really matter to you (the builder, not the spectator) that you have an accurate / correct chassis? what i mean is, does it matter if you have the bars placed correctly or is it o.k. as long as you stuff a lot of bars in there and it looks close? i realize that plastic and brass tubing don't match up one to one and sometimes concessions must be made but, do you even try to get close with the correct diameters?

[tyrone]

Dave... I try to get mine as close as I can ... although I know they are not accurate, I dont use a jig or anything like that.. I mainly just eyeball it and test fit alot before gluing everything in place...

[RAT-T]

I WOULD LIKE TO GET AS CLOSE AS POSSIBLE TO SIZE & REGULATIONS JUST FOR THE CHALLENGE.

BUT I'M FINDING THE HUNT FOR REFERENCES CAN BE QUITE THE CHALLENGE AS WELL

[Prostreet]

I Tried to make mine as close to real thing as possible using different size rod where it should be to make it look accurate. When i first started mine i have to admit i wasn't really to worried about it being 100% accurate, But during the build i found my self taking it apart in certain parts to change it to make it more accurate. I still didn't do some things right but made notes to make that stuff right on the next one. I do want mine to resemble the 1:1 as close as possible as i can. I notice myself getting very anal about details now, but that is the way i would like to build.

[d.k.v]

To make it accurate just get a copy of your local drag racing spec.

 

I have complete rules for australia and it includes the tubing type size and desgin requirements.

[TedsModeling]

I'm researching for a 55 Chevy Pro Sportsman I'll be building next. I found chassis plans online that I resized to get my scale 115" wheelbase. I may have a crossbrace missing or incorrect, but like the others above, I want it as close as possible. The people who would see it (friends, family, club members) wouldn't know anyway.  By the time the chassis is complete, the body installed, engine plumbed and cockpit detailed, some minor missing details would probably be lost or covered up.

I've researched the body and engine almost as much as the chassis, but the chassis is an important item to get close to correct.

Why are you asking, Dave?

[comp1839]

just curious to see what does and doesn't matter to people when they build. there are specific rules that govern rollcage / chassis construction. they are not available in your local drag racing spec. you can go to the rule book to see what spec your chassis needs to be but, after that you need an SFI  manual to determine tubing placement and diameters. for instance:

 

pro stock requires SFI spec 25.1e

pro mod requires SFI spec 25.1e or 25.2

top sportsman (if quicker than 7.49 sec.) requires SFI spec 25.1e or 25.2 or 25.3

                        (if 7.50 or slower) requires SFI spec 25.1e or 25.2 or 25.3 or 25.4 or 25.5

 

i have read the 25.2 manual and i'll give you a for instance. there are 4 different rollcage configurations that are approved for 25.2. they range from the driver helmet being in front of the main hoop to the drivers head being behind the main hoop. the location of the drivers head (so to speak) denotes the locations of the rest of the tubing. same with the floor tubing options, dash /lower windsheild bar and gussets, and the cross tubing in the halo bar. how the flooring sheetmetal is attached is also spec'd. so, questions like Tom's about a pro mod / pro sportsman ( i'm guessing he really means top sportsman) chassis flooring aren't always cut and dried answers. the two could be the same or they could be different.

 

any way. for those of you to whom it matters. there are rules that govern what, where, and how tubing should be placed. i'll post some pics of the rollcage differences when i can.

[Mooneyzs]

Dave... are these specs out of the NHRA rule book by chance?? sounds like it is an SFI manual. I have a couple of rule books and sounds like I need to pick up an SFI manual for my pro mod build.

[comp1839]

yes, the chassis spec. is called out in the nhra rulebook (SFI spec. 25- whatever). you would need to aquire the SFI manual for that spec. the specs i listed are stricktly door car specs. dragsters (front or rear engined), funny cars altereds, street roadsters. all have there own specs. depending on how fast you want to go.

 

again, this only applies to the builder who wants to make sure his stuff is correct. not everyone builds that way.

[RAT-T]

THANKS FOR THAT INFO DAVE.

TED WAS KIND ENOUGH TO SHARE HIS RULEBOOK WITH ME, BUT I HAD A HARD TIME CHECKING OUT THE SPECS FOR THE SUPER GAS CLASS, THEY SEEM TO MAKE YOU RUN BACK & FORTH BETWEEN OTHER CLASSES, BUT WHEN YOU GET THERE IT SAYS TO CHECK GENERAL REGULATION, SO WHEN YOU CHECK THERE IT SAID CHECK SFI SPECS NO. ????? SO THAT EXPLAINS QUITE A BIT, DO YOU KNOW IF THE SFI BOOK COVERS ALL THE CLASSES, OR DOES EACH CLASS HAVE IT'S OWN SFI BOOK?