I'm new and need advice. Look at my prints and suggest some machines please!

[moonbogg]

Hi,

I'm a draftsman and I have some drawings I made for my hobby. I was trying to get quotes to have the parts machined from people I know who own shops, but they don't even have the time to quote my dinky little parts. I have the material here already. My design is nearly 100%. All I need is to buy the machines to make my parts myself because I have decided, that for me, it simply isn't practical to rely on others to make my little hobby stuff anymore. It worked once in the past for a similar project, but I need to be independent now.
Even though I've designed parts for about 17 years now for others to machine, when it comes to buying the machines to make them myself I am feeling surprisingly lost and overwhelmed. I thought the best thing to do was include images of my drawings so you can suggest what lathe capacity to get and a mill to buy. I am looking to spend as much as $4,000 for both of these machines, but I'd like to spend less if I can get away with it. I won't be making parts often. The machines will see some very infrequent and light use (at least that's what I suspect for now).
I have 6" round stock (short pieces 3 1/4 and 1 3/4" long) that I need to turn down to make the front and rear cap parts. I figured I'd turn them down to the 5.5" dia first, then machine the other diameters and then mill the flats. I would then do the holes. I suppose I could mill the flats first and chuck it up square in the lathe and maybe get away with a lathe that has a smaller chuck, but I'm afraid that could be cutting it too close. I'd be stuck at the absolute minimum of my lathe capacity needs, right?
I will be installing the machines in my garage. I have normal house electricity and I am a complete electrical noob, so I don't know what my amp or voltage capacity is. Whatever is the normal, standard weak sauce electricity is what I have, I'm sure.
I was thinking a Smithy 3 in 1, but those are almost $5,000 just for the machine and I'm not even sure I'd be happy having to break setups every single time I want to switch from lathe to mill etc. I think I'd be annoyed by that. I can see myself working on brackets for my project and getting all into it, and then deciding I'd like to take a break and turn some parts to do some experimenting on, but won't be able to. I'm leaning more toward a Grizzly lathe and mill, but I don't know what size lathe to get (chuck diameter that it comes with) for my parts. I assume a 3 jaw 6" chuck is what I need to machine 6" diameter stock, but what if I want to make something a bit larger at 6 1/2 or 7"? I wouldn't ever go larger than 7" I'm fairly certain, and I'd be happy enough if the largest I could work with was 6" diameter.
Sorry for the long post. See drawings below. Also, I think I'd need a boring bar for the piston housing. Is it reasonable to expect that I could machine that with a little boring bar? All parts are 6061-T6. I have a small 17-4 stainless part to make, but it's only 7/8" dia by about 3" long, so no big deal there.
For the 3 1/2" SCH 40 part, would I need a steady rest to clean up the OD? The OD doesn't have to be clean, but I don't think it would turn true since that's going to be from SCH40 pipe, so I think I need to clean the OD first and then turn the small lengths in the ID so the parts will fit cleanly inside. Sound right? I always take the machining for granted but now I have to do it myself, lol. I also could make the piston housing from a thick walled pipe or tube. It doesn't have to be from solid stock as noted.
All of my projects will be of a similar nature, perhaps just the next size up for the pipe, so 4" SCH40. This would drive all the diameters about 1/2" larger and that would represent my maximum needed capacity in terms of diameter.

 

[benmychree]

Don't even think 3 in one. Your spending proposal does not reach the requirement for equipment to achieve the result you want in machining the parts you are showing. I advise that you avoid using schedule 40 pipe for anything but a pipeline or structural use, it is not at all nice to machine or achieve fine finishes. I'd be looking for a 12" or 14" X 40" lathe and a heavy bench top mill or Bridgeport mill.

 

[moonbogg]

A Bridgeport mill? You mean the massive, full sized mills that you see in machine shops everywhere? Also, does it need to be "heavy"? When I see heavy, I think expensive. I just need to mill the aluminum flat. I don't need to hog anything out and I have all the time in the world to do it.

 

[Moderatemixed]

Hi Moonbogg.

I’ve read your post several times. I’m brand new at this but let’s just lay things down and look at this realistically. If you’ve never machined before don’t expect to be able to turn out the parts that you have drawn immediately. The machinists and millwrights out there have spent years perfecting their craft, and to suggest that you just have to buy machines and “Shazam Presto” you’ll be making accurate parts is unfortunate at best. The budget that you are proposing is not out of line if you are going to buy small, older machines and take the time to repair and tune them into shape, a process that has taken me 5 years. But.... you should double your budget if you want a DRO, some quality tooling and the metrology equipment to layout and cut the stock.

While I stop short of saying that what you are proposing is impossible, you might do better to find the “mom and pop” machine shop in your area, county, state, province, district, municipality, or community and hire them to make your parts. They can use the business and you might just save yourself a tone of heartache.

If you are interested in proceeding however, listen to the guys on these forums. They have all “seen it and done it” and you will learn from them. The guidance that they give is valid and well founded.

Good luck, I’m guessing that you are going to need it.


Sent from my iPad using Tapatalk

 

[Aaron_W]

As a hobbyist I have the similar reaction when I hear Bridgeport. That is a big piece of machinery, but I've learned that in the working machinist's world, a Bridgeport is a small mill.

I'm a pretty new to this stuff myself, so I'm not entirely sure what is needed to make the parts you have illustrated. There are members here like John (above) who have been machining forever and are much better able to help you there.

If you want to turn something of 6" diameter, you might just barely have room on a 10" lathe, but would be really pushing your limits. When you see 10x22, or 12x36 those are theoretical maximum sizes if you stuck the piece to be machined directly to the spindle. The practical working diameter is really about 1/2 that size.

The same goes for length, 22" on a 10x22 lathe seems pretty generous, but that distance is from the spindle nose to the tip of the tail stock. When you add a chuck, you are going to lose 3-5", if you want to drill something out, so add a drill chuck and bit into the tail stock, there goes another 4-6". So on a fairly simple drilling operation you very easily lose about 1/2 your available working length.

I agree with John, I don't think you want to look at a lathe smaller than 12", although since your parts aren't long you might be happy with one of the shorter bed lengths, rather than the standard 36". There are some shorter 12x24 and 12x28 lathes and I think Atlas even made a 12x18.

If you look Mills find the X,Y,Z travel and that will give you some idea of the size box you have to work with. I would think you could get away with one of the medium size bench mills, particularly since you are working with aluminum, Something like a Precision Matthews PM-25 or Grizzly GO761. Of course at $2000+ for these you are getting into the price range of a larger used mill like a Millrite or various Bridgeport clones which will be more capable with more room for growth.

Electricity is going to be another problem. Most of the machines suitable for your project are going to need 220v power. That isn't a huge issue 220 is available in most every home often being used for electric stoves and electric clothes dryers, but you will probably need to hire an electrician to install a couple of 220v outlets in your garage.


and last is tooling... Tooling is the thing that gets all of us when we are new. Micrometers, dial indicators, calipers, end mills, lathe bits, boring bars, chucks, collets etc add up quickly and even being frugal can easily add up to 1/2 the cost of the machine or more.

 

[benmychree]

A Bridgeport mill? You mean the massive, full sized mills that you see in machine shops everywhere? Also, does it need to be "heavy"? When I see heavy, I think expensive. I just need to mill the aluminum flat. I don't need to hog anything out and I have all the time in the world to do it.

Yes, but a smaller mill would probably supply your needs --- In the larger scheme of things, a Bridgeport mill is not considered to be BIG in any industrial setting, they are the LCD of industrial milling machines.

 

[moonbogg]

Thanks for the replies. I have some machining experience. I've had a couple manual machining classes and a CNC class and I cut chips in each of the classes. I've been around machines for 17 years, just never had to buy one. Accuracy isn't a huge concern and I am confident that I can make these parts. I have confidence in myself and enough experience to know that with some practice, I can become functional in a short time. Hiring people to do my hobbies is never going to happen again, unless I decide to send the parts for anodize. I don't feel like messing with acids in the garage, lol.

This is just my hobby. The drawings specify the tolerances because someone else was going to be making these parts and they needed to be specified. I can just machine them to fit and get it close enough. I have a couple calipers and a mic. No need for digital displays.

I think the 12" lathe suggestion is just about perfect. I'm less sure about the mill.
Can we talk brands? Bolton and Grizzly are priced well. If I have to spend a little more then I'll do it. I know tooling and a table for the lathe and various unexpected stuff is going to add up. The one thing I was sure about was NOT spending 5 grand on a Smithy 3 in 1. Good point on the electrical, although most of these machines come in 110v variety. Would that not work for some reason? Too many amps or something?

 

[mksj]

I would only look at machines from Grizzly or Precision Mathews, I would avoid most of the other vendors unless you want to waste your money. Features, Quality Control and Service are pretty bad with most other vendors. On paper they might look OK, but get them to your house and you might find a whole mess of issues or lack of features, with no recourse. I know a few people who purchased Boultons and that was the case. Looking at the size and type of work, major limitation is the lathe, I would want a 11", preferable 12" as a minimum. The two below are a D1-4 chuck mount which is very standard and both lathes are large bore (1.5") spindles that are uncommon in lathes of this size. It makes a significant difference. Unfortunately due to the import tariffs, prices have gone up significantly for Chinese machinery.
Sort list:
PM-1127VF-LB Lathe https://www.precisionmatthews.com/shop/pm-1127vf-lb/
PM-1228VF-LB Lathe https://www.precisionmatthews.com/shop/pm-1228vf-lb/

PM-727V Mill https://www.precisionmatthews.com/shop/pm-727v/

A lot of people have purchased the above machines, you can read about them in the forum or watch videos online. You really haven't set up a budget for tooling, so you need to factor that in.

The tolerance you have specified are very tight, not sure how you can achieve the tolerances on the piston housing and boring that deep with such a thin wall. So maybe some more thought on specific materials and if it is doable as outlined. Layout and drilling holes on the mill, you might consider a cheap DRO that will do bolt circles, maybe other functions. You can do it all manually and count dials but time consuming and easy to make mistakes. I would probably mill the flats first and then hold it with a 4J independent chuck, then turn the other round dimensions, you will need to grind tooling or get special tooling for some of the grooves. The 4J independent does come with the PM-1127VF-LB, but is extra on the PM-1228VF-LB.

Looked at the Grizzly lathes, I can't find anything in the price range that will have the capacity you probably need at your price range, they have the G4002 which would be the smallest I would consider. Mill wise you might look at the Grizzly G0795Z, but more expensive then the PM-727V. Also note that the G0795Z is 220V. The PM-1127VF, PM-1228VF-LB and PM-727V are 120V. Not a lot of choices these days. Buy once, cry once, so if it comes down to a small price difference get the better/bigger machine.

 

[Nogoingback]

How many parts do you need to have made? There are machine shops that will do small runs but you might have to
look a bit harder. Remember, the cost of the machines is only the beginning: tooling (especially for the mill) will add
considerable cost. If your goal is just to get the parts made and the quantity is small, it doesn't make sense to buy
machines. If you really want to get involved in machining as a hobby, that's a different matter.

If you want the name of a machine shop that will make parts in small quantities, PM me. There's one in Portland
that does that. My son used to work there.

You can also put stuff like that out for bid on https://www.emachineshop.com

 

[moonbogg]

I would only look at machines from Grizzly or Precision Mathews, I would avoid most of the other vendors unless you want to waste your money. Features, Quality Control and Service are pretty bad with most other vendors. On paper they might look OK, but get them to your house and you might find a whole mess of issues or lack of features, with no recourse. I know a few people who purchased Boultons and that was the case. Looking at the size and type of work, major limitation is the lathe, I would want a 11", preferable 12" as a minimum. The two below are a D1-4 chuck mount which is very standard and both lathes are large bore (1.5") spindles that are uncommon in lathes of this size. It makes a significant difference. Unfortunately due to the import tariffs, prices have gone up significantly for Chinese machinery.
Sort list:
PM-1127VF-LB Lathe https://www.precisionmatthews.com/shop/pm-1127vf-lb/
PM-1228VF-LB Lathe https://www.precisionmatthews.com/shop/pm-1228vf-lb/

PM-727V Mill https://www.precisionmatthews.com/shop/pm-727v/

A lot of people have purchased the above machines, you can read about them in the forum or watch videos online. You really haven't set up a budget for tooling, so you need to factor that in.

The tolerance you have specified are very tight, not sure how you can achieve the tolerances on the piston housing and boring that deep with such a thin wall. So maybe some more thought on specific materials and if it is doable as outlined. Layout and drilling holes on the mill, you might consider a cheap DRO that will do bolt circles, maybe other functions. You can do it all manually and count dials but time consuming and easy to make mistakes. I would probably mill the flats first and then hold it with a 4J independent chuck, then turn the other round dimensions, you will need to grind tooling or get special tooling for some of the grooves. The 4J independent does come with the PM-1127VF-LB, but is extra on the PM-1228VF-LB.

Looked at the Grizzly lathes, I can't find anything in the price range that will have the capacity you probably need at your price range, they have the G4002 which would be the smallest I would consider. Mill wise you might look at the Grizzly G0795Z, but more expensive then the PM-727V. Also note that the G0795Z is 220V. The PM-1127VF, PM-1228VF-LB and PM-727V are 120V. Not a lot of choices these days. Buy once, cry once, so if it comes down to a small price difference get the better/bigger machine.

Good stuff here, thanks. I am looking at the Grizzly G0704. It's priced very nicely and comes with a stand. It looks big enough and quite frankly, overkill for what I need. I just need to machine some little flats on small aluminum and stainless pieces. I will also be milling some brackets instead of sending them to waterjet as originally planned. Nothing thicker than 1" 6061-T6. No one has mentioned that Grizzly. Is there something wrong with that mill?
For bolt circles, I can just make a hole table if I need to drill that many holes, which I won't ever need really. I can just dimension the drawing from zero to the hole to make it easy for me.
Precision matthews is going to be too expensive. It will have to be Grizzly and they are looking more and more like the one to go with for me considering what you mentioned about other brands having poor customer service, etc.
I won't be making a lot of parts at all. Just a little hobby project once in a while. I want independence, so sending parts out is a no go for me. I want to experiment and work on prototypes and just have fun. I can't do that if I have to constantly send little parts out to shops. Honestly, by the time I pay someone to machine all my stuff, including water jet, all the milling work, all the lathe work, the drilling and tapping etc, I could almost buy a machine or two. It's impractical as a hobbyist like me to use outside shops.
So, regarding turning 6" dia stock on a 6" chuck, you just reverse the jaws, right? What about cleaning up sections of a long piece of 2 1/2" pipe in a 12" lathe; could I do something like that with a steady rest? Some of the grizzly's come with a steady rest.

Thanks again!