After spending the day making oil drain flanges I needed a break and decided to work on a project I'd been putting of. I think it's a H series valve cover, although I don't know. It's for a shop I make parts for and this was a special request from the owner.

The hardest part was getting everything set up and positioned, after that it's just a matter of pressing the button and hoping you did everything right



All in all I'm quite happy with how it turned out. It's not 100% but it's damn close and I can't really justify spending hours and hours on something like this. Mostly I'm just happy I don't have to tell him I wrecked his valve cover

 

Looks great!

What type of mill or engraving bit are you using to get such sharp corners?

 

It's a trick I discovered because I do a lot of engraving and was unimpressed with the commercial bits.

I use a .25 hss spot drill running at 4500rpm (my machines max) and 20-36 ipm depending on the cut. The only problem with doing it this way is all the lines have a 45* edge, although personally I like the look better. The reason I stick to hss is that I find the ones I buy have roughly a 0.01" flat on the bottom, where as the carbides are almost a perfect point. Pockets are a bit slow to do so for a large pocket I might rough it out with a .125" end mill and then run around the edges/corners with the spot drill.

 

why not try a ball nose endmill? i've done this sorta thing with a regular flat bottom endmill (1/16") and it works pretty good. i think the biggest thing holding you back is the 4500rpm. it'd be nice to run something like that above 10k. i think it turned out pretty good though!

 

the 4500 rpm is a bit limiting for stuff like this, but whats more limiting is tool rigidity. A 0.0625" (1/16th) end mill doesn't have a lot of meat to it and isn't going to be very forgiving of feeding it 200%-300% faster then you should. The ballpark figures for 0.0625" ballnose endmill work out to roughly 21,000 rpm feeding at 10 ipm. So thats 4 times the rpm and it would still take twice as long for certain jobs. This is why we actually use a .25" (1/4) spot drill instead of a 0.125" (1/8), they snap at the feedrates we typically run.

You can get fairly detailed with a small cutter, but we have found the spot drills allows us to be more detailed (0.010" line width, 0.005" corner radius) while running harder and faster.

Here is an example of a custom part we made for someone. We actually made 5 of them, they are roughly 2.5" in diameter...... as you can imagine being able to half the cycle time on something like this makes a big difference.




Sorry for the long winded response. I like talking machining and sharing information. I know I would have loved to have been told about this a few years agao

 

thats pretty cool. its a b series valve cover btw.

 

What kind of mill you have there? Using spot and center drills were actually what I was taught to use for engraving.

 

Did you engrave the soldier part? I can't seem to tell whether its inset or not. Looks trick tho.

 

It's a Tormach. It's small (16x10x16 cutting) and under powered (1.5hp) but it get's the job done. It's not really ideal for really large production runs, but seeing as how I do a lot of one offs/small runs (10-200) it works for now. I've been looking at some bigger ones recently, but just haven't found the right one for my needs.

I'm not surprised that you were taught to use spot drills, it works great. Although talking to others in the industry it doesn't seam to be common knowledge. I've talked to my tooling supplier about it and I'm his only customer that he knows of that does it that way.

No the soldier is not inset, he is actually raised up and all of the little details in his clothes and what not are inset. It's hard to tell because all the edges have a 45* angle which makes the transition from inset to raised appear smoother. Thanks

 

Strange, I thought that was more of a common industry thing, all my friends that are machinists do it that was so thats what I picked it up. Always interesting talking to other machinists and seeing how they tackle the same problem.

I think I talked to you a couple years back, I seem to remember talking to you about your machine back when I had an old Tree cnc knee mill.

I can't believe you run 100-200 parts on that machine with no tool changer!? Have you build an enclosure for it?

 

It's probably more common then I have been lead to believe, sadly i don't actually know a lot of other machinists. It's common to use a sport drill to chamfer edges, engraving is basically the same thing. I love chatting with other machinists, you learn some truly amazing tricks. My favorite to this day is how to cut a .498 slot with a 0.500 end mill

I think we may have talked before. It's always hard to remember who I've talked to and who I just know from seeing on the the forums. You are local so we've probably chatted or bumped into each other .... automotive is a fairly small world, especially in BC.

Yeah a tool changer would be nice, although all my tools are set up in the control software as well as my cam program so when I switch jobs I don't normally have to change the tool table. Tool changes take about 20-40 seconds which is half the time of the last big machine (it was older) I was looking at. Although I will admit making parts with a 4-5 minute cycle time and 3-4 different tools is pretty brutal. Yes I have a fullish enclosure. I built it myself as I wasn't happy with the one available for my machine. I gave up on the front door after breaking it a few times and now I just use a thick piece of plastic and some magnets .... it's ugly as sin but works like a charm and is easier to deal with in a small shop with limited floor space.

Large runs are interesting, and with my current machine I'm sure a bit more labor intensive. I have low overhead and a very reasonable shop rate so even if it might take me a bit longer to make an individual part, my rates are almost always more then fair. I actually got into this because I was sick of paying through the nose for stuff I needed made, or worse being told they wouldn't make my parts unless I ordered larger quantities. I understand that if your machine cost 250k+ and can hold tolerances of 0.0001" that it can warrant a high hourly rate, but honestly for almost everything automotive 0.001" is more then good enough. A lot of my non automotive customers are in the same position. They need a small quantity of parts made with tolerances of 0.001" - 0.005" but can't justify paying through the nose for them.

 

Great Job!!

 

I put .010 holes in parts all day long

 

Thanks. The owner was quite happy and actually asked me to do it again for a customers car this time.

What are you making that needs such small holes?.

Here are a couple pictures of some small parts made by others using the same machine as me. The first is a name or something, the second are some 0.0079" diameter holes. You can see the grain of rice in the picture for reference.

 

I dont make any parts were I work. We mainly put small holes/slots/ in parts such as military, aerospace, and medical. Why do they need such small hole I have no idea. I've been doing visine molds for a while now. Putting a .011-.012 hole in the mold so when you squeeze the bottle it will make droplets..

We actually just did an engraving about that size not to long ago in a brass part.

 

I've always found micro machining really interesting, although I'm not sure how much I would personally enjoy it.

 

That valve cover looks bad ***... What does a job like that run?

 

I do a fair bit of work for that shop so I always try to cut them a good deal on the oddball stuff, especially when it's not on any sort of definitive timeline. I also already had their logo in solidworks so it was fairly simple to generate the toolpaths.

I won't throw out any actual numbers as that is private to my customer, and I'm not sure if I'm allowed to discuss dollar values without it being construed as advertising ..... better safe then banned. I however will PM you a bit more information.

 

when i did engravings on both CNC machines we had at school most of the time i used a center drill for name writing and stuff like that. It gave the nice 45* on either side ot the flat like you said, i actually made a palte with my name on it doing that and i think it looked great

 

This stuff is so cool. I really really love this stuff. I have never touched anything with machining, and wish I could learn ...

Is this the type of thing you can learn by picking up an old milling machine and starting to read stuff here and there?

 

Yep, like anything, you can teach yourself, but it will take significantly longer to learn and you will never be as good as a guy that was trained by a master.

 

Yes you can learn it on your own, but the learning curve is very steep. There are some great books and good forums for information.

 

Definitely, I don't have squat for machining books but I am sure there are some great ones out there. I have also learned a decent amount from internet forums.
I started learning machining and cnc milling in highschool, but at the time didn't have a lot of interest in it, or metal working as a career in general. Things obviously changed and now most of the valuable machining knowledge I gain is from the other machine shops I do welding for. Most of the guys are pretty cool and will swap welding/beer/pizza/friendship for teaching. I figure a lot of it out myself, but there are some tricks you can't get anywhere else to suit your application and machines than from a grumpy old german machinist that can swing by your shop and tell you what you need to change.

 

Hah, grumpy old german machinists rock! Funny you use this as an example, I haven't gone to many machine shops in my life, maybe 2-3 total, one of which was run by a grumpy old German dude. That guy had A LOT of equipment, and he spent about 30 minutes talking about how everyone is cheap, no one cares about quality, the industry sucks, the world sucks, everyone and everything sucks, and if you work in the industry, run for your life ... basically.

 

Yeah old grumpy German machinists are truly something else. I've met 1-2 and they are a fountain of information but they will only share it with you if you are hard working and appreciate it. They have a great appreciation for well made, well engineered tools and understand the value in spending good money on your tools.

I think it comes from an old fashioned mentality of working hard and doing a good job. No matter how menial the task, making sure you do it to a level you can be proud of. As simplistic as that might sound it's really not that common these days. I know there are a lot of very hard working people out there, and this forum is a great example of it, but there are also way too many people that expect more then they are due.

I've been dealing with this exact problem lately, and it just baffles me. This summer I hit critical mass and have been having a hard time manufacturing everything as well as dealing with shipping/package 200+ items a month. In order to focus on the manufacturing aspect I decided to find a reseller to basically take over selling for me. This is pretty much a no brainer as they would just be picking up the sales I have been making consistently for the last 2 years. I know it's not glamorous and honestly some of the products are silly seaming, but with a 40%-50% retail margin in automotive I figured it was a good opportunity, hell I wish someone was willing to show me how to make 1K= extra every month for maybe 20-30 hours of work. I actually had one guy that made it sound like he would be doing me the favor and would only do it if I gave him one of my seller accounts. Maybe I'm just getting old, but it baffles me that people think you can get something without working for it.....sorry venting a bit, I didn't think I'd have such a hard time finding 1 maybe 2 hard working people that wanted to build something for themselves.

On a bright note I got something amusing from my tooling supplier today, I'll take pictures in a bit