Metal cutting question- chisel edge - Page 2 - Woodworking Talk - Woodworkers Forum
Reply
 
Thread Tools Display Modes
post #21 of 36 Old 09-15-2014, 11:28 PM
Senior Member
 
OnealWoodworking's Avatar
 
Join Date: Apr 2013
Posts: 1,128
View OnealWoodworking's Photo Album My Photos
Quote:
Originally Posted by woodnthings View Post
Since you stated that my posted response may not be the correct practice unless, you will probably get a "corrected" response. And here's why:
Aluminum does not need a metal cutting blade with a coolant wash ....unless you are running a very high speed blade at 3000 or so FPM for extended lengths of time and cutting very thick stock.
For an occasional cut, a woodcutting bandsaw with a woodcutting blade will work absolutely fine. The width of the blade is irrelevant. The only portion of the blade in contact with the material is the set on the teeth, not the bare portion of the blade...no heat generated, no contact.... unless you are cutting curves and even then you may want a greater set to the teeth OR a more narrow blade depending on the radius.


Here's a project I made using all aluminum which I cut using my woodcutting blade 6 TPI, no coolant:
http://www.woodworkingtalk.com/membe...-modification/











A metal cutting jigsaw or hacksaw blade will load up with the aluminum and be worthless fairly quickly in my experience.

Carbide is the way to go here for what this person is cutting. He can either use his regular tablesaw blade or chopsaw blade. Both will cut thin aluminum just fine and not mess up the carbide teeth if he goes slowly.

When cutting thin aluminum it is sometimes helpful to sandwich the aluminum between a few pieces of hardwood before cutting. This keeps the thin stock from flopping around any and gives support to the backside to help reduce any sort of 'tearout' or 'rough edges'.
OnealWoodworking is offline  
Sponsored Links
Advertisement
 
post #22 of 36 Old 09-16-2014, 05:38 AM
Village Idiot
 
epicfail48's Avatar
 
Join Date: Mar 2014
Location: Springfield MO
Posts: 4,709
View epicfail48's Photo Album My Photos
Quote:
Originally Posted by woodnthings View Post
Aluminum does not need a metal cutting blade with a coolant wash ....unless you are running a very high speed blade at 3000 or so FPM for extended lengths of time and cutting very thick stock.
3000 fpm, like that which a wood cutting bandsaw would be running for. Again, my advice was concerned more with heat buildup and premature wear on a blade thats probably meant more for woodworking. Im not arguing that your way may be more right than mine, but that doesnt make mine more wrong or make me clueless.

Id also like to agree that in an ideal world, there wouldnt be any contact on the blade save for that on the teeth, but we dont live in an ideal world. Again, my initial suggestion was based on the theory that by using a 1/4 inch blade over one larger, say a 1/2 inch blade, you reduce the material that risks contacting the work piece and causing a heat buildup by half. You yourself also just admitted that youve used a 6tpi blade meant for woodcutting to saw aluminium, and thats hardly the proper practice, being that a woodcutting blade is only really supposed to be used to cut wood.

Im not arguing that youre wrong and my way is superior, merely stating that my way works well for me in particular, and i do apologize if im coming across that way. Ive just got issues with people automatically assuming that i dont know what im talking about because theyve tried a different way

I need cheaper hobby
etsy.com/shop/projectepicfail
epicfail48 is offline  
post #23 of 36 Old 09-16-2014, 07:15 AM
where's my table saw?
 
woodnthings's Avatar
 
Join Date: Jan 2009
Location: SE, Michigan
Posts: 25,940
View woodnthings's Photo Album My Photos
cutting wood vs aluminum vs steel

You can use the very same blade on aluminum and wood, 6 TPI or so but NOT the same cutting speed. This chart from MIT explains it:
http://web.mit.edu/machineshop/Bandsaw/speeds.html

and the blade type:
http://web.mit.edu/machineshop/Bandsaw/blades.html

As does this discussion:
http://www.vansairforce.com/communit...ad.php?t=69243

Just like when drilling steel you use a slower speed than drilling wood. A 10 to 1 reduction is required as a general rule.

I weld my own bandsaw blades from roll stock. I have many different tooth sizes and widths depending on what material I intend to cut. I use the same blade stock on my woodcutting bandsaws as on the slower metal cutting bandsaws, which I only use for cutting mild steel. I have cut steel up to 3" solid rounds.... no problems, no coolants, just the correct speed, about 100 to 300 FPM. The wood cutting speeds are between 1000 and 3000 FPM. When you get into high speed production cutting you will need a coolant wash.

Bimetal blades and carbide tipped are used for production and last longer than carbon steel and HSS blades:
http://freetechnicalcharts.com/Band_..._for_Metal.php

http://www.bandsawbladesonline.com/i...iewDoc&docId=9

The answer to your question will only be as detailed and specific as the question is detailed and specific. Good questions also include a sketch or a photo that illustrates your issue. (:< D)

Last edited by woodnthings; 09-16-2014 at 08:03 AM.
woodnthings is online now  
The Following User Says Thank You to woodnthings For This Useful Post:
OnealWoodworking (09-16-2014)
Sponsored Links
Advertisement
 
post #24 of 36 Old 09-16-2014, 11:11 AM Thread Starter
In The Basement
 
aaronhl's Avatar
 
Join Date: Jun 2011
Location: Central Connecticut
Posts: 460
View aaronhl's Photo Album My Photos
Quote:
Originally Posted by GeorgeC View Post
You are not really trying to make a real chisel are you?

George
No Iam not it's a metal part for a model boat called a "turn fin". One side needs to be tapered as it will "slice" through the water. Here is a picture of what I am trying to make, it's on the right side of the back of the boat



aaronhl is offline  
post #25 of 36 Old 09-16-2014, 11:20 AM
Wood Snob
 
Al B Thayer's Avatar
 
Join Date: Dec 2011
Posts: 5,960
View Al B Thayer's Photo Album My Photos
Knowing what I know about working with aluminum and model boats. You could clamp that down and sand or shave it off with a hand sander or some 120 stuck to a small piece of wood.

As to the model. The trailing edge needs to be sharp and then make it a tiny bit blunt to reduce drag and cavitation.

Al


Al B Thayer is offline  
post #26 of 36 Old 09-16-2014, 02:46 PM Thread Starter
In The Basement
 
aaronhl's Avatar
 
Join Date: Jun 2011
Location: Central Connecticut
Posts: 460
View aaronhl's Photo Album My Photos
Quote:
Originally Posted by Al B Thayer View Post
Knowing what I know about working with aluminum and model boats. You could clamp that down and sand or shave it off with a hand sander or some 120 stuck to a small piece of wood.

As to the model. The trailing edge needs to be sharp and then make it a tiny bit blunt to reduce drag and cavitation.

Al
Thanks for the info. I think I might try sanding it with a block. Might end up making a few of them so I would like to make them consistent. That's what I like to do with a lot of my work.

Not sure what you mean by making the trailing edge blunt? Do you have a diagram?
aaronhl is offline  
post #27 of 36 Old 09-16-2014, 04:43 PM
Senior Member
 
Join Date: Jul 2008
Location: Florida Panhandle
Posts: 11,850
View GeorgeC's Photo Album My Photos
Quote:
Originally Posted by aaronhl View Post
Thanks for the info. I think I might try sanding it with a block. Might end up making a few of them so I would like to make them consistent. That's what I like to do with a lot of my work.

Not sure what you mean by making the trailing edge blunt? Do you have a diagram?
Think very slightly rounded. Like the blade of a butter knife.

George
GeorgeC is offline  
post #28 of 36 Old 09-16-2014, 10:26 PM Thread Starter
In The Basement
 
aaronhl's Avatar
 
Join Date: Jun 2011
Location: Central Connecticut
Posts: 460
View aaronhl's Photo Album My Photos
Wouldn't you want sharp, square trailing edges? Guess not?
aaronhl is offline  
post #29 of 36 Old 09-17-2014, 04:36 AM
Wood Snob
 
Al B Thayer's Avatar
 
Join Date: Dec 2011
Posts: 5,960
View Al B Thayer's Photo Album My Photos
Quote:
Originally Posted by aaronhl
Wouldn't you want sharp, square trailing edges? Guess not?
George is correct. Straight and flat in water produces drag and cavitation.

Al


Al B Thayer is offline  
post #30 of 36 Old 10-01-2014, 07:19 PM Thread Starter
In The Basement
 
aaronhl's Avatar
 
Join Date: Jun 2011
Location: Central Connecticut
Posts: 460
View aaronhl's Photo Album My Photos
I tried sanding a 1/8" thick piece with 80 grit sandpaper (and block) Would take so long getting the perfect edge. I might try to dremel most of it off and then finish with the file. Maybe a very coarse file will work better than sandpaper.

I was thinking of making another piece that would need a curve in it. Not sure how I would bend it
aaronhl is offline  
post #31 of 36 Old 10-01-2014, 08:54 PM
Senior Member
 
Danno's Avatar
 
Join Date: Apr 2009
Location: Ajax, Ontario, Canada
Posts: 526
View Danno's Photo Album My Photos
Quote:
Originally Posted by aaronhl View Post
I tried sanding a 1/8" thick piece with 80 grit sandpaper (and block) Would take so long getting the perfect edge. I might try to dremel most of it off and then finish with the file. Maybe a very coarse file will work better than sandpaper.

I was thinking of making another piece that would need a curve in it. Not sure how I would bend it
As Al said earlier, I'd use the table saw. You could make a jig to hold the piece at the angle you're looking for.

As for curving the piece, are you talking about curving along the length, or width? If you're talking length, 1/8" aluminum would be fairly easy to bend if you're not looking at a tight radius.
Danno is offline  
post #32 of 36 Old 10-02-2014, 09:58 PM Thread Starter
In The Basement
 
aaronhl's Avatar
 
Join Date: Jun 2011
Location: Central Connecticut
Posts: 460
View aaronhl's Photo Album My Photos
Yes next step is to make a jig for the table saw. I think that will work really well

Here is a picture of the metal turn fin you can see on the right side of the picture.

aaronhl is offline  
post #33 of 36 Old 04-20-2015, 11:33 PM Thread Starter
In The Basement
 
aaronhl's Avatar
 
Join Date: Jun 2011
Location: Central Connecticut
Posts: 460
View aaronhl's Photo Album My Photos
OK guys I am back again
I bought a metal cutting blade for my table saw- it cuts aluminum very easily, just like a piece of wood!! So far I only cut angle to length and next I plan on making the beveled "knife" edge on another piece.
I will let you guys know how that goes. So easy to cut aluminum on the table saw
aaronhl is offline  
post #34 of 36 Old 04-21-2015, 12:08 AM
Senior Member
 
Join Date: Dec 2014
Location: Illanoyed
Posts: 308
View Tree Hugger's Photo Album My Photos
A single cut mill flat bastard would make short work of a part like that...finesse here not a race.
Sure files load up, that's why they make file cards.
From a larger piece of stock , file your bevel first ( drill ect) then cut your part to size ...lots easier to hold onto that way.
Tree Hugger is offline  
post #35 of 36 Old 04-21-2015, 08:31 AM
Senior Member
 
Join Date: Sep 2011
Posts: 25,991
View Steve Neul's Photo Album My Photos
Personally cutting aluminum on a table saw I would recommend using a full face shield rather than just safety glasses. I've cut both steel and aluminum on a table saw before.
Steve Neul is offline  
post #36 of 36 Old 04-21-2015, 08:45 AM
Really underground garage
 
Join Date: Aug 2010
Location: mnts of Va
Posts: 2,552
View BWSmith's Photo Album My Photos
Safety alert.....

Might want to do a bit of reading on the subject of Aluminum dust.Start with OSHA.

Sorry...back to regular programming

Those who say it cannot be done shouldn't interrupt the people doing it.
BWSmith is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Woodworking Talk - Woodworkers Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
My first hand chiseled mortises need glue msbeal Joinery 24 05-22-2013 08:21 AM
Cutting metal bits for Kalimbas ktmhz General Woodworking Discussion 2 11-06-2012 11:26 AM
Looking at used Metal Cutting bandsaw Sleeper Power Tools & Machinery 2 08-01-2012 08:47 PM
Bandsaw metal cutting blade....? David R Power Tools & Machinery 7 07-19-2010 11:06 PM
large chiseled tenons bbaley Joinery 8 02-09-2010 11:57 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome