Re: Porting Bits...Cut and Lifespan
[Re: Triple Threat]
#1988525
01/11/16 03:49 PM
01/11/16 03:49 PM
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Joined: Jan 2004
Posts: 13,247 Mt. Vernon, Ohio
dartman366
I Live Here
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I Live Here
Joined: Jan 2004
Posts: 13,247
Mt. Vernon, Ohio
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single cut is for soft material and will cut faster and grab the material, more for use on aluminum, double cut is for harder material and won grab as bad and also leaves a smoother surface on both iron and aluminum but alum will clog them up, I use WD40 while cutting alum.
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.
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Re: Porting Bits...Cut and Lifespan
[Re: dartman366]
#1988532
01/11/16 04:00 PM
01/11/16 04:00 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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single cut is for soft material and will cut faster and grab the material, more for use on aluminum, double cut is for harder material and won grab as bad and also leaves a smoother surface on both iron and aluminum but alum will clog them up, I use WD40 while cutting alum. Yep... plus I use both air and electric for doing port work.. I have a reaostat that I can dial down the rpm.. I use the WD-40 also... on my alum burrs/bits I use wax also(if I have it.. keeps them from loading up.. as to rpm.. dont know what it is... but you will know when its cutting well.. dont over heat your burrs or they will get dull in a blink.. spend the money on quality burrs... I just bought 2 new ones the other day.. they were $22 each for the good ones from a abrasive compan (the short shank ones).. my long shank ones range from 6" long to 12" long.. I only have 1 12" one
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Re: Porting Bits...Cut and Lifespan
[Re: MR_P_BODY]
#1988598
01/11/16 04:50 PM
01/11/16 04:50 PM
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Joined: Jan 2004
Posts: 13,247 Mt. Vernon, Ohio
dartman366
I Live Here
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I Live Here
Joined: Jan 2004
Posts: 13,247
Mt. Vernon, Ohio
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I ghecked a couple of my air motors and they are rated at 25,000 rpm at 90 psig.
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.
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Re: Porting Bits...Cut and Lifespan
[Re: dartman366]
#1988603
01/11/16 04:52 PM
01/11/16 04:52 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I ghecked a couple of my air motors and they are rated at 25,000 rpm at 90 psig. I regulate my air grinders with the trigger.. a finger under and over the trigger to get less RPM
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Re: Porting Bits...Cut and Lifespan
[Re: Baxter61]
#1988659
01/11/16 06:20 PM
01/11/16 06:20 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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I use air, got a valve in the line to keep max speed under control easier and I run 2 air compressors, my big 80 gallon one will get behind after a while so I just piggy back my little 10 gallon one into another shop hose and they keep up great together.
For aluminum I use the aluminum bits with wd-40 and finish em with the iron cutter and lots o wd-40. I buy bits from mac tools guy, he warrantys them when they chip a tooth. Expensive but worth it.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: Porting Bits...Cut and Lifespan
[Re: Baxter61]
#1988738
01/11/16 08:02 PM
01/11/16 08:02 PM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
super stock
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super stock
Joined: Mar 2010
Posts: 984
Tennessee
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When youre porting cast iron heads, do you use a single cut or double cut bit? And how (ie how many ports/heads) do your bits last? What kind of grinder speed do you use? What about on aluminum? My claim to fame? is that I started a machine tool business for the owner almost 20 years ago. Wonder of wonders, we are STILL in business! LOL. At any rate, to answer your question: Single angle carbide burrs are for aluminum. The flutes are wide apart and deep to evacuate the large chips that Aluminum and other "non ferrous" materials produce. A "double cut" is a carbide burr with shallow flutes, spaced close together. This is the burr to use for cast iron which produces a small, powder like chip. Also with harder materials, you want to have more cutting edges to take the maximum amount of material possible per revolution. As for speed, a rule of thumb is 400-500 surface feet per minute in steel and iron. 1,000 surface feet per minute to 6,000 surface feet a minute in aluminum. The enemy of the tool is heat. To calculate surface feet per minute (SFM) to revolutions per minute, use this simple formula: SFM X 3.82 / diameter. Example: 1/4" diameter burr in cast iron. 500 x 3.82 = 1,910 / by diameter (.250)= 7,640 rpm. Aluminum: 1,000 x 3.82 =3,820 / .250 = 15,280 rpm. Now you know why your die grinder turns 30,000 rpm! If you stay within these recommended parameters, you should get the maximum life from your expensive carbide burrs. Also note that aluminum tends to stick to the carbide, gumming it up. In computer controlled CNC machines, we use a special coolant to help with this. If you could get a gallon of this from a local machine shop,(pre mixed right out of the sump of their machine) and put it in a spray bottle, it will extend the life of your tools. But, beware! It will sling coolant everywhere! especially at 15,000-30,000 rpm!
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Re: Porting Bits...Cut and Lifespan
[Re: FastmOp]
#1988740
01/11/16 08:03 PM
01/11/16 08:03 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Myself.. my alum bits never touch steel or iron.. if I clog a alum bit I stop and let it cool and spray it then pop the alum out of the bit.. they will load up with heat... also I dont use my steel bits on alum.. if I want it a bit smoother I will hit it with tootsie rolls.. but not fine ones.. unless its the exhaust side.. I like the exhaust side SMOOTH
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Re: Porting Bits...Cut and Lifespan
[Re: Baxter61]
#1988998
01/12/16 01:04 AM
01/12/16 01:04 AM
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Joined: Jan 2003
Posts: 4,275 Morrow, OH
markz528
master
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master
Joined: Jan 2003
Posts: 4,275
Morrow, OH
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I'm confused. So do you all agree with this statement of the link above?
1. Carbide burrs can be used on many materials
Tungsten Carbide burrs can be used on most hard materials: metals including steel, aluminum and cast iron, stone, ceramic, porcelain, hard wood, acrylics, fibreglass and reinforced plastics.
Different cuts of carbide burs will be best suited to certain materials, see the next point below to find out about the different cuts. 2. Carbide burrs commonly come in two cuts; single cut and double cut
Single cut (one flute) carbide burrs have a right handed (Up cut) spiral flute. These tend to be used with steel, copper, cast iron and ferrous metals and will remove material quickly with a smooth finish.
Double cut or Cross cut carbide burrs tend to be used on non ferrous metals, aluminum, soft steel, plastics and hard wood. Double cut or cross cut (2 flutes cut across each other) will leave a slightly smoother finish than single cut due to producing smaller chips as they cut away the material.
67 Coronet 500 9.610 @ 139.20 mph 67 Coronet 500 (street car) 14.82 @ 94 mph 69 GTX (clone) - build in progress......
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Re: Porting Bits...Cut and Lifespan
[Re: markz528]
#1989046
01/12/16 02:28 AM
01/12/16 02:28 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I'm confused. So do you all agree with this statement of the link above?
1. Carbide burrs can be used on many materials
Tungsten Carbide burrs can be used on most hard materials: metals including steel, aluminum and cast iron, stone, ceramic, porcelain, hard wood, acrylics, fibreglass and reinforced plastics.
Different cuts of carbide burs will be best suited to certain materials, see the next point below to find out about the different cuts. 2. Carbide burrs commonly come in two cuts; single cut and double cut
Single cut (one flute) carbide burrs have a right handed (Up cut) spiral flute. These tend to be used with steel, copper, cast iron and ferrous metals and will remove material quickly with a smooth finish.
Double cut or Cross cut carbide burrs tend to be used on non ferrous metals, aluminum, soft steel, plastics and hard wood. Double cut or cross cut (2 flutes cut across each other) will leave a slightly smoother finish than single cut due to producing smaller chips as they cut away the material. I am not understanding what they are saying.. a alum burr has wide cutter on it(single cut)... I will put up a link for both alum and steel/iron burrs.. a double cut is used on steel/iron EDIT When I'm doing alum I get it close with a single cut burr.. then I fine tune it with a tootsie roll thats medium to heavy grit(it will vary on how close I was with the burr).... on iron I will get it a lot closer with the burr(double cut burr) then fine tune it with a course tootsie roll.. you can getthe burrs in multiple styles and shapes... I like egg shape and tree shape.. in different sizes and cuts Also.. the carbide or tungsten carbide is just the material its made out of.. you can get the same burrs in either material https://www.pferdusa.com/products/202b/index.htmlthis one is for steel.. its a double cut style http://www.mscdirect.com/product/details/85284982?item=85284982&fromRR=YHemi Ragtop has good assessment of each type and the chip off of each
Last edited by MR_P_BODY; 01/12/16 12:59 PM.
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Re: Porting Bits...Cut and Lifespan
[Re: Baxter61]
#1989363
01/12/16 05:45 PM
01/12/16 05:45 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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So what normally causes the burr to skip off the iron? Too little RPM or too much? Dull burrs.. also if you dont have good control of the grinder... high speed and sharp burrs will will cut nicely but I dont like the high speed... if it bites it will fly around the port multiple times before you get it stopped.. I prefer a slower speed and good control on the grinder.. on my electric one the switch is on the end which is a push to turn off... if I bump it off it will bite... but I tend to keep my one hand right near the button/switch and the other hand well forward.. this gives me better leverage and control... I like the electric unit so I dont have to listen to the compressor running.. and its a BIG compressor EDIT Dull bits/burrs people tend to push harder and it causes heat.. thats when things get weird.. if you are leaning on them you tend to have less control.. sharp bits/burr you dont lean on them to get them to do the work.. so with less pressure you tend to have better control
Last edited by MR_P_BODY; 01/12/16 06:07 PM.
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Re: Porting Bits...Cut and Lifespan
[Re: Baxter61]
#1989772
01/13/16 10:54 AM
01/13/16 10:54 AM
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Joined: Sep 2004
Posts: 2,093 oberlin, Ohio
Rapid340
top fuel
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top fuel
Joined: Sep 2004
Posts: 2,093
oberlin, Ohio
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I prefer using burrs recommended for aluminum (wide single cut) when porting iron heads.
1971 Factory Appearing Duster 340 11.000 @ 122 mph
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