Cooling Fins
Cooling Fins
What is the best tool to use on a lathe to cut cooling fins on cylinders ? I have tried using a parting tool but the blade wanders off to one side or the other.
A hand ground HSS grooving tool would do the job, and cost you almost nothing. In order to grind one successfully, you should have a firm understanding of why a tool cuts, and what features effect performance. That's not something you're likely to read in a book----it comes from trial and error. I can offer you some guidance if you'd like.
Understand, a properly ground tool won't be a compromise---it will do a great job and leave a decent finish---it's all in how you grind the tool and what lubricant you use while cutting. The sole exception to this is if you're machining mild steel, which can be very challenging.
Harold
Understand, a properly ground tool won't be a compromise---it will do a great job and leave a decent finish---it's all in how you grind the tool and what lubricant you use while cutting. The sole exception to this is if you're machining mild steel, which can be very challenging.
Harold
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- Posts: 307
- Joined: Sat Jan 04, 2003 12:24 pm
- Location: SE Washington State, near Moscow, Idaho
I use a cutoff tool and have never had a problem. If your cutoff blade is wandering off to the southwest you might want to check a few things.
1) Have the cutting edge exactly at center height. You can check this with the old machinst's ruler trick. If your not familiar with the technique, you place one of those little 6" machinist's rulers between the cutting edge and the part being machined. Lightly advance the cross slide until the ruler is clamped between the two. If the edge is at the correct height, the ruler will be vertical. If not, it will be cocked off at an angle.
2) Make sure your cutoff tool is perfectly perpendicular to the lathe axis. One way to do this is to face off a piece in the lathe, then mount the cutoff tool and bring it alongside the faced surface. Place a piece of white paper on the ways below the tool to afford good visibility. Sight directly down onto the cutoff tool. If you see a wedge-shaped gap of light between it and the faced surface, you are not square. Adjust your cutoff tool until it is perfectly aligned.
3) Hone the edge of your cutoff tool razor sharp. When doing cooling fins I like to have the edge square with the tool. Make sure the corners of the cutting edge are not rounded off.
I like to use a slow RPM and powered cross-feed. I always use brushed-on kerosene as a lubricant for aluminum. This prevents a "built-up" false cutting edge that could make the tool go astray.
The results are very satisfactory as seen in the pictures on these Web pages:
http://users.moscow.com/oiseming/lc_ant_p/pic_Prj1.htm
http://users.moscow.com/oiseming/lc_ant_p/pic_Prj8.htm
http://users.moscow.com/oiseming/lc_ant_p/pic_Prj6.htm
Good luck!
Orrin
1) Have the cutting edge exactly at center height. You can check this with the old machinst's ruler trick. If your not familiar with the technique, you place one of those little 6" machinist's rulers between the cutting edge and the part being machined. Lightly advance the cross slide until the ruler is clamped between the two. If the edge is at the correct height, the ruler will be vertical. If not, it will be cocked off at an angle.
2) Make sure your cutoff tool is perfectly perpendicular to the lathe axis. One way to do this is to face off a piece in the lathe, then mount the cutoff tool and bring it alongside the faced surface. Place a piece of white paper on the ways below the tool to afford good visibility. Sight directly down onto the cutoff tool. If you see a wedge-shaped gap of light between it and the faced surface, you are not square. Adjust your cutoff tool until it is perfectly aligned.
3) Hone the edge of your cutoff tool razor sharp. When doing cooling fins I like to have the edge square with the tool. Make sure the corners of the cutting edge are not rounded off.
I like to use a slow RPM and powered cross-feed. I always use brushed-on kerosene as a lubricant for aluminum. This prevents a "built-up" false cutting edge that could make the tool go astray.
The results are very satisfactory as seen in the pictures on these Web pages:
http://users.moscow.com/oiseming/lc_ant_p/pic_Prj1.htm
http://users.moscow.com/oiseming/lc_ant_p/pic_Prj8.htm
http://users.moscow.com/oiseming/lc_ant_p/pic_Prj6.htm
Good luck!
Orrin
So many projects, so little time.
I have posted a picture, below, that shows a parting tool that is hand ground. It's the one on the right, with a different parting tool to its left, showing the side.
There's a real advantage to grinding your own tool. For one, you can grind the precise width you'd like to achieve, or, if you'd like to rough the fins and go back for a light finish cut, you can grind the tool slightly undersized, working to centers, then go back and take a skim cut off the sides of the fins. Unless your tool is terribly dull, it will take the cut with no problem, particularly if you're machining a decent grade of aluminum.
Right now I'm attempting to post on HSS grinding, but it's proving to be a difficult task for me. There are so many variables that it's difficult to set guidelines that might be helpful without knowing circumstances. Your case is no exception. If you can give me a little detail on what you're doing (depth and width of fins, and material being machined) I may be able to give you some specific guidelines. I've ground parting and grooving tools as long as I have memory of the shop and have never had difficulty with them. Nice thing is, they're not hard to grind if you're willing to change how you normally grind tools. I'll talk about that, too, if you're interested. I had planned to, anyway.
Harold
There's a real advantage to grinding your own tool. For one, you can grind the precise width you'd like to achieve, or, if you'd like to rough the fins and go back for a light finish cut, you can grind the tool slightly undersized, working to centers, then go back and take a skim cut off the sides of the fins. Unless your tool is terribly dull, it will take the cut with no problem, particularly if you're machining a decent grade of aluminum.
Right now I'm attempting to post on HSS grinding, but it's proving to be a difficult task for me. There are so many variables that it's difficult to set guidelines that might be helpful without knowing circumstances. Your case is no exception. If you can give me a little detail on what you're doing (depth and width of fins, and material being machined) I may be able to give you some specific guidelines. I've ground parting and grooving tools as long as I have memory of the shop and have never had difficulty with them. Nice thing is, they're not hard to grind if you're willing to change how you normally grind tools. I'll talk about that, too, if you're interested. I had planned to, anyway.
Harold
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Tag,
It's in process as we speak. I've put in considerable time composing something I hope will be of assistance, but it's far from finished. I will also grind a tool and post a picture that is representative of one of the most useful and functional of all hand ground tools, a boring bar. Anyone that can duplicate the design with success will come to understand the value of the method I use. A bar such as this is truly superior to almost any other bar available.
Please be patient- I'm spread thin---and still struggling for words.
Harold
It's in process as we speak. I've put in considerable time composing something I hope will be of assistance, but it's far from finished. I will also grind a tool and post a picture that is representative of one of the most useful and functional of all hand ground tools, a boring bar. Anyone that can duplicate the design with success will come to understand the value of the method I use. A bar such as this is truly superior to almost any other bar available.
Please be patient- I'm spread thin---and still struggling for words.
Harold
Hey,
I just found this post and remembered a website that has information on cutting model engine cooling fins.
http://modelenginenews.org/techniques/fins.html
Enjoy
I just found this post and remembered a website that has information on cutting model engine cooling fins.
http://modelenginenews.org/techniques/fins.html
Enjoy
Andrew
You can use a cross slide mounted milling attachment
http://i135.photobucket.com/albums/q158 ... C00712.jpg
in conjunction with carbide slot drills & endmills the possibilities are, as they say, endless,
Nick
http://i135.photobucket.com/albums/q158 ... C00712.jpg
in conjunction with carbide slot drills & endmills the possibilities are, as they say, endless,
Nick