Best way to remove material?

Topics include, Machine Tools & Tooling, Precision Measuring, Materials and their Properties, Electrical discussions related to machine tools, setups, fixtures and jigs and other general discussion related to amateur machining.

Moderators: GlennW, Harold_V

pete
Posts: 2518
Joined: Tue Feb 10, 2009 6:04 am

Re: Best way to remove material?

Post by pete »

I've got almost a full collection of the Model Engineer magazine from the very first in 1898 that predated the Model Engineer title up into the 1960s plus lots more in the 1980's - 2,000s. Jobs like that were almost always done by marking out, center punching them, drilling lines of holes that almost touched each other and the outside profile line, then it was recommended "a gentle tap" with a hammer would remove the waste. Few in the U.K. with home shops before maybe the mid 1970s had anything like a vertical mill. A great many never even had a drill press. The lathe got used instead of that or a mill for everything. And I've seen some pretty impressive part shaping in those magazines done using only a lathe. Water jet cut would be great, but I agree and think the same about doing as much as possible yourself. A someone else mentioned a variable speed jig saw with a decent metal cutting blade, and the corner holes drilled for access for the saw blade would be about the most simple and quickest method most of us will have in our shops. Then a final clean up on the mill using coordinates. I'd think most of those long gone M.E. types would have filed the internal profiles after the waste was removed. Sawing the waste off is almost always quicker than drilling, and drilling is quicker than machining. Some very complex internal part shapes were done in industry with a vertical bandsaw, breaking the blade then rewelding it after it was joined up inside a drilled hole on the the part where the cut was wanted. I doubt much of that even gets done anymore since there's better and faster ways to do the same thing today.
Mr Ron
Posts: 2126
Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Best way to remove material?

Post by Mr Ron »

NP317 wrote: Wed Aug 15, 2018 6:27 pm When I've had jobs like yours, I have drilled each inside corner with the frames together;
Separated the frames and used a roughing cutter to mill out around the edges;
Re-joined the frames and performed the final trim milling to dimension.
Deburr, clean up, and go make a good margarita!
~RN
Sounds like a plan.
Mr.Ron from South Mississippi
User avatar
rudd
Posts: 754
Joined: Wed Dec 12, 2007 11:21 pm
Location: savannah ga.

Re: Best way to remove material?

Post by rudd »

Honestly, you already seem to have a CAD drawing. Give that and the material to a waterjet shop. I think I paid less than 200 a few years ago for a mogul frame that was made of thicker material, 1/2" plate.
Bentworker
Posts: 223
Joined: Fri Mar 02, 2012 1:29 am
Location: State of Jefferson

Re: Best way to remove material?

Post by Bentworker »

I'd probably lay it out with dye, drill out all the material I could, then clamp them down to a rotary table just to make dealing with all those goofy angles a little easier. If you were to get carried away with the math you could probably do the whole job off the DRO with the rotary table, but would have to precisely set a center point on the part to the center of the rotary table and figure everything off of that point. Probably take you longer to crunch the path numbers than it would to cut it all by layout marks and eyeball. Kind of depends on tolerance...

Or find someone with a waterjet.
Shop toys...
10X54" Vectrax GS20F mill with DRO & frequency drive (saved from the scrap pile).
Jet 13x40 lathe.
Powermatic 1150 drill press.
I love Craigslist!
Glenn Brooks
Posts: 2930
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: Best way to remove material?

Post by Glenn Brooks »

Earlier this year I finally broke down and bought a plasma cutter. Best purchase I ever made. Currently I am making some coupler pockets and have one process where I need to remove a 2” x 3.75” rectangular piece from the center of a bunch of face plates that the pockets fit into. So a very similar process to what you pose in this thread.

I kind of did the same as others suggest: drill holes in each corner to establish rounded corners, then rough cut inside the lines with the plasma cutter. Finally used a roughing end mill to mill the rectangular dimension to proper size. Wow, the plasma is really nice to work with. Much finer, more controlled cut than oxy torch.

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....
whateg0
Posts: 1114
Joined: Sat Mar 28, 2009 3:54 pm
Location: Wichita, KS

Re: Best way to remove material?

Post by whateg0 »

Glenn Brooks wrote: Thu Aug 23, 2018 12:10 am Earlier this year I finally broke down and bought a plasma cutter. Best purchase I ever made. ...

Glenn
Build yourself a CNC table for it and you'll be living the life! I built mine a few years ago and while it doesn't get used every day, it sure does cut straighter lines and curvier curves than I could ever do by hand, even with a template!

Dave
Mr Ron
Posts: 2126
Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Best way to remove material?

Post by Mr Ron »

I finally got the pieces cut out, using the drill/mill way of removing material. Everything went great. I used the DRO where I could although I'm not 100% up on DRO operation. I modified the parts by eliminating the "blips" that extend into the waste. I instead made a separate piece and half lapped it into the frames; much better overall. Designing and building model locomotives is a long learning process for me, but I am learning something new and hopefully useful at least to me personally. It is gratifying to say the least. I know others will look at the work I do and not realize what I go through, but that doesn't matter to me. It's all about how I feel about what I do. I consider machining along with woodworking an art comparable to painting/ sculpture/ writing, etc; it doesn't get the attention it deserves.
Mr.Ron from South Mississippi
Mr Ron
Posts: 2126
Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Best way to remove material?

Post by Mr Ron »

I used my new DRO to remove all the waste material from my loco frames. For the angle cuts, instead of rotating the vise, I mounted the work on my rotary table and adjusted it to follow the line. The cuts may be off a degree or 2, but it is not critical. So far, the frames are coming along nicely. I hope to be able to download pictures taken with my cell phone to my PC so I can post them, but so far, it's not cooperating. I have an old XP computer sans bluetooth.

BTW, I realized my son who lives right next door had a plasma cutter and he could have cut the frames for me in minutes. I'll have to remember that for my next project.
Mr.Ron from South Mississippi
johnfreese
Posts: 219
Joined: Thu Jan 21, 2016 2:10 am

Re: Best way to remove material?

Post by johnfreese »

I would drill a single hole in each opening then use a scroll saw to get close to the layout line . It would require sawing one plate at a time. After both are cut, fasten them together and file to the layout line.

It could also be done on a mill but would require a lot of setups to cut all the angles. If a rotary table were available the part could be clamped to the RT and the angles established that way.
Mr Ron
Posts: 2126
Joined: Tue Dec 22, 2009 12:36 pm
Location: Vancleave, Mississippi

Re: Best way to remove material?

Post by Mr Ron »

johnfreese wrote: Sun Aug 26, 2018 5:01 pm I would drill a single hole in each opening then use a scroll saw to get close to the layout line . It would require sawing one plate at a time. After both are cut, fasten them together and file to the layout line.

It could also be done on a mill but would require a lot of setups to cut all the angles. If a rotary table were available the part could be clamped to the RT and the angles established that way.
I finished cutting the frames using the mill and a rotary table for the angles and it went fine. As you mentioned using a scroll saw, how effective would it be to cut 3/8 thick aluminum with a scroll saw. I think of a scroll saw as being a woodworking tool and maybe useful on thin sheet metal, but 3/8"; I'm not so sure.
Mr.Ron from South Mississippi
johnfreese
Posts: 219
Joined: Thu Jan 21, 2016 2:10 am

Re: Best way to remove material?

Post by johnfreese »

A scroll saw on 3/8 aluminum would be miserably slow.
Post Reply