runt13
Jr. Member
 Offline
Age: 44
Location: J-town new jersey
Posts: 84
|
 |
« on: March 25, 2010, 04:02:00 PM » |
|
i have a question about cutting chrome moly. what is best, hack / band saw or chop saw?
i use a chop saw for all my regular fabrication, but was woundering if using a chop saw would harm the chrome moly.
RUNT
|
|
|
|
|
Logged
|
who would have guessed it would take so long to go so fast for such a short time?
2012 willmington mile p/pp-1350-4 record holder 132.6mph
|
|
|
geh458
Full Member
Offline
Age: 54
Location: Oxnard, CA.
Posts: 123
|
|
« Reply #1 on: March 25, 2010, 04:26:00 PM » |
|
I wouldn't think it would mater, but you would lose a tiny bit more material using a chop-saw versus a horizontal band-saw (blade width is narrower). You'd wear yourself out using a hacksaw, but then again if that's all you have on hand....
All of the people I know that do fabrication work use a horizontal band-saw.
|
|
|
|
|
Logged
|
Gifford Hawn
Vintage Sports Car Racer looking to convert.......
|
|
|
johnneilson
Sr. Member
Offline
Age: 51
Location: N 34 ° 15 ' 0 '' W 118 ° 21 ' 53
Posts: 271
|
|
« Reply #2 on: March 25, 2010, 04:31:18 PM » |
|
cutting the material shouldn't give you any issues.
Generally speaking, the "heat affected zone" is an issue with welding/temperatures.
There is lots of information on this subject, most I agree with.
Carrol Smith books, I forget, I think "Engineering to win" is a good reference point.
Personally, I have built many frames and repaired many others. Even some of the alloys from Europe respond well to the same theology as 4130.
John
PS, I use a portable band saw to cut material, if having to modify in the field a hacksaw is better than a torch.
|
|
|
|
|
Logged
|
1st Gen Miata Fiberglass and Carbon Fiber components from legendary Molds. www.jnent.net |
|
|
|
1212FBGS
|
|
« Reply #3 on: March 25, 2010, 05:46:33 PM » |
|
i use little baby chipmunks..... and being an environmentally conscious guy that i am, i recycle them into my stew pot when there little teeth are worn to the quick.....
Kent
|
|
|
|
|
Logged
|
|
|
|
runt13
Jr. Member
Offline
Age: 44
Location: J-town new jersey
Posts: 84
|
|
« Reply #4 on: March 25, 2010, 08:37:31 PM » |
|
thanks folks, heat was my concern. i have a nice horizontal band saw, i just happen to be in a chassis shop and saw [no pun intended] them using a chop saw, when i asked about the heat they all looked at me with the worn out chipmunk look, then said good question, we never thought of that.
RUNT
|
|
|
|
|
Logged
|
who would have guessed it would take so long to go so fast for such a short time?
2012 willmington mile p/pp-1350-4 record holder 132.6mph
|
|
|
geh458
Full Member
Offline
Age: 54
Location: Oxnard, CA.
Posts: 123
|
|
« Reply #5 on: March 26, 2010, 02:10:30 PM » |
|
No mater which cutting implement you use, heat buildup will not be a concern on the chrome moly if you keep the blade lubricated. I'd worry more about the blade getting too hot, not the tubing.
|
|
|
|
|
Logged
|
Gifford Hawn
Vintage Sports Car Racer looking to convert.......
|
|
|
|
fredvance
|
|
« Reply #6 on: March 26, 2010, 03:45:06 PM » |
|
When I am cutting something heavy or am concerned about heat, I run water where the blade/wheel is cutting.
|
|
|
|
|
Logged
|
WORLDS FASTEST PRODUCTION MOTORCYCLE 213.470
Vance&Forstall Racing
All 9 SCTA 1350 NA records
WOS 2011 235+MPH
Engine by Knecum, Tuned by Johnny Cheese.
Sponsers Catalyst Composites, Johnny Cheese Perf, Knecum Racing Engines, Murray Headers, Carpenter Racing
|
|
|
|
1212FBGS
|
|
« Reply #7 on: March 26, 2010, 07:27:43 PM » |
|
so what do ya think creates more heat... cutting the tubing or welding it?....
love ya
Kent
|
|
|
|
|
Logged
|
|
|
|
|
interested bystander
|
|
« Reply #8 on: March 28, 2010, 06:05:06 PM » |
|
Kent, will your quiz be graded?
Hard to beat a chop saw for speed, have used "cold saws" which are slow but . . . COLD as they claim when the cut's done.
Have never had a car crash from a part chop-sawed, but cockpit failure caused a couple.
|
|
|
|
|
Logged
|
5 mph in pit area (clothed)
|
|
|
38Chevy454
Jr. Member
Offline
Age: 48
Location: Tijeras, NM (Albuquerque)
Posts: 97
|
|
« Reply #9 on: March 30, 2010, 02:02:37 PM » |
|
You are cutting the end and (I presume) going to weld it to something. The high heat from welding will cause more concern with the metal than the much lower heat from cutting. Cr-Mo has to be TIG welded because with MIG the heat affected zone will harden and you have a very strong but brittle zone there. Welding will always mess up whatever the material condition was to start with. Designers and stress engineers use annealed (weakest) properties for analyzing the strength of any welded joint.
|
|
|
|
|
Logged
|
I used to have a handle on life, but it broke.....
|
|
|
WhizzbangK.C.
Full Member
Offline
Age: 51
Location: Kansas City, MO
Posts: 107
Ed Bennett, Speed Team Doo Kansas City fab shop.
|
|
« Reply #10 on: March 30, 2010, 07:56:45 PM » |
|
With chop saws I've always been more concerned about the possibility of the material in the wheel being embedded in the cut and contaminating the joint. Not that I've ever seen anything about it being a problem, but I was taught to file the end lightly while deburring the tube just in case. The heat really shouldn't be a concern, as was pointed out earlier, it gets hotter during welding than the saw gets it.
|
|
|
|
|
Logged
|
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of. Douglas Adams
|
|
|
manta22
Hero Member
 Online
Age: 73
Location: Tucson, AZ
Posts: 547
What, me worry?
|
|
« Reply #11 on: June 05, 2010, 12:00:40 PM » |
|
If you are not cutting a large amount of tubing, try a reciprocating saw. I use a Ryobi (similar to a Sawz-All) with a bi-metal blade and CoolTool cutting fluid. It works just fine and beats the "Armstrong hacksaw" by a mile. I dress the jagged saw cut end on a belt sander using zirconium oxide abrasive-- it lasts longer than the more common aluminum oxide abrasive.
Regards, Neil
|
|
|
|
|
Logged
|
Regards, Neil Tucson, AZ
|
|
|
|
