[fatboy55]

Hello everyone,

I have my new manual IH mill all set up and cutting great. Orignal motor. So far I'm very happy.

I'm cutting some 1x2 inch bars of 6061. I need to cut 1/2 inch deep into almost the full 2 inch width. Then a notch on the opposite side from where the left over 2 inch section is left standing. The bars are 3 and 6 feet long.

_
l l
l l__________
l l_
l_____________l

This is close to what the profile looks like from the side.

I've made one with standard end mills, 3/8 and 1/2 but it took too long. The notch at the right end was fast and easy but milling down the 1 3/4 inch wide horizontal plateau was time comsuming.

Aaron suggests a 6 flute 1 inch wide end mill. Before I went out and bought one I thought it might be wise to get the cnczone opinion.

How would you all handle this tooling problem, what would you use?

I'll need to make a good number of these bars over the next year so the tool does not have to be very cheap.

Thanks for the help everyone

Jeff

[fatboy55]

The text graphic got messed up. Theres a bracket l_ right under the first long horizontal line, it should be moved to the right forming a notch at that end.

Jeff

[kentavv]

How do you plan on holding the pieces?

[mrainey]

Normally for roughing aluminum with an end mill, fewer flutes are recommended rather than more. Most people go with a two or three-flute tool, for better chip clearance.

I don't know enough about your machine and setup to offer much advice.

[kentavv]

With such a large diameter end mill and no need to cut a slot a few more flute is probably not going to hurt. In fact with a max speed of 1800 RPM the additional flutes would aid with feed rate. But as mrainey said - look out for chips packing in the end mill. Feeding manually you will be able to see/feel it happening.

[Cruiser]

There is a six flute for aluminum, special grind and it'll need to be wet, or cooled and lubed somehow. the lube is important to keep the alum flowing and not sticking, and keep the cutting force pushing head toward column or it'll buck and lift. you'll want to keep speed down so you'll have enough torque to drive it and just feel the feed and keep it moving.

[fatboy55]

Hey everyone, someone asked how I'm holding the pieces. I'm using three screwless vices in a line. This holds the bars every 10 inches or so.

Right now I'm trying a 3/8 2 flute mill the full depth of cut, .500 its going pretty well! No cooling, just a squirt bottle of stuff. At to top it all off, I'm climbing!!!! At 1/2 inch thick, no problem. I love this mill

Jeff

[fatboy55]

So, no one has even a single suggestion for the best tool to hog out aluminum with?

This is an importaint project for me, I would really appreaciate some help with this.


Jeff

[Cruiser]

"ground For Aluminum" !

[fatboy55]

Ah Cruiser, forgive me. I did forget about your suggestion on the 1 inch wet em. Didn't mean to include you when I said "no suggestions yet"

What do you mean by "grounds for aluminum"? Is that something like "thems fighting words"

I've got the machine up to about 4 or 5 inches per minute with a 3/8 end mill .500 deep using just a squirt bottle of lube/coolent at 900 rpm (H/2 on the IM mill gear box) Do you think I could go faster at 1600 rpm with just my squirt bottle? Im using HSS em's now and there holding up VERY well even after a lot of milling. A few days in fact.

I think if I go faster I'll have to switch to carbide, the heat might be a bit much for HSS at that point. What do you think. I don't want to go fully cooled. I'm only cutting alum and don't want the hassle of setting it up right now.

Jeff

[ZipSnipe]

If ya got a bandsaw cut most of it with that then clean it up with a 2 flute endmill.

[Cruiser]

Fatboy, It means that the cutter has a special relief,shear,& helic ground into it so the shear is clean and chips flow from cutter faster and in carbide they are awsome in a high speed spindle. i suggest going to someplace like JLIndustrial.com and look thru some of the tooling notes, many differant co's will give a brief on the tools to application ....... edited ....... get an air siphon that will blow some air and a small amount of liquid and use that with some mild soapy water for your coolant But be sure to protect the cast iron with your oil during and after or better yet get some mister coolant concentrate (spendy)

[fatboy55]

If ya got a bandsaw cut most of it with that then clean it up with a 2 flute endmill.

Man I wish I could but its the long way, not the short. I would need a cut 6 feet tall for the larger bars, 3 feet for the shorter!

Cruiser, thanks for the "ground for alum" recomendation. I've seen those in all the catalogs, very tough looking tool.

The coolent, really cutting fluid I'm using is amazing. Its called Big Orange by Zep. Not the stuff in the stores, thats diluted with water. In florida you have to order it. About 30 dollars a gallon but amazing on aluminum. Useless on steel but in al. nothing better! Its the pure form of the orange cleaners. Non toxic and a little bit goes a long way. No rust too.

I'll try one of those tough looking end mills in carbide and a drip feed of the orange stuff. I'll put the machine as fast as it'll go and see how much powerfeed I can give it.

What is an air siphon? I was thinking about a little blowing air to get the chips away but air siphon???

Thanks again.

Jeff

[Cruiser]

an air siphon is something you'll have to make, it is similar to a "mister" but more air ! it is made to the same rules of a jet in a carb ventury in that the air will escape into a slightly larger tube from a nozzle and at that point the air pressure will decrease, this is the ideal point for a capilary tube to draw liquid up and mix it in the air, very little liquid is used, it is mostly air. I have made these to wash the machine down at work, lots of fluid tho and full flow air. just note the principal above and find some cheap supplies to experiment it can be quite entertaining while your bored, we even make nail shooters and don't ask !

[fatboy55]

Thats pretty cool (pun intended) but I don't have shop air at that location yet.

I was thinking about making a simple drip feed system from a plastic coke bottle, that plastic thing that holds the coke bottle to the side of your car door, but in this case the top of the mill's column, and some IV stuff from the local drug store / medical supply. Should be very cheap, fast and work well.....plus, I like coke :-) no pepsi in my cutting fluid IV.

Jeff

[ZipSnipe]

oops my bad , I didn,t see that the bars are 3 to 6 ft long. Yep in that case 2 flute cutter and lots of coolant.

[project5k]

if and or when you do get shop air supply... go to your local chepo tools place, (i like hargor freight) or whereever you can find a short air snoozel.. er nozel, the one with a hole or holes in the side and stick a small tube in the side of it.. you can play with the placement of the tube till you get the amount of liquid you want.. i use ths setup on one of my lates.. i have a 5 gallon bucket under the lathe bench and it will draw the coolant up the 3 or so feet and then mists the part... works well but be carefull of the mist vapors.. your atomizing a liquid, so it better be something your willing to breathe....it works kinda the way a cheap sand blaster works.. air goes through and sucks up the sand... its cheap and works really well.. but does require some fiddeling with to get the air supply pressure and volume set up.. there is probably a commercially avilable version of this... but im a cheapskate...i also use a fish tank valve on the liquid line to control the flow of coolant...