Which milling machine model?

Discussion in 'General foundry chat' started by Zapins, Jan 31, 2021.

  1. Zapins

    Zapins Gold

    I'm budgeting for a milling machine in the next few months looking at the end of April or May. I've been looking at different models.

    I'm thinking a bridgeport series 2, 4 hp with power feeds. Or a converted CNC bridgeport-mill of some type.

    What models should I stay away from?

    What models should I keep an eye out for?
  2. Robert

    Robert Silver

    A BP Series II is a larger heavier version than the series one. Probably too heavy for a hobbiest. I would stick with a series I. I am no expert in the head models but I would try to get a variable speed. There is a lot that can go bad in the head so check that out carefully. There are a lot of clones out there that are also good machines so it does not need to be an actual BP. I would definitely make sure you get a spindle with an R8 taper. That will be easiest to find tooling for. Some of the smaller mills like the Clausing, Rockwell, Burke have MT or B&S tapers.
    If you have space limitations and not so much budget limitations, look at the Precision Matthews 728.
    Jason likes this.
  3. A Bridgeport clone with a CAT30-40 taper spindle would be nice to have for the increased rigidity and horsepower capability, especially if CNC. Also there's less competition and cheaper prices when buying secondhand tooling compared to the R8 taper and 40 taper tooling is pretty common and relatively cheap secondhand.
  4. Jason

    Jason Gold

    Series 1 Zap. I can just about promise you will not outgrow that machine. AND get the longest table you can find. This will help when you need to make a long pass on the X.
    If you get some little BS 36inch table, you'll be lucky if you can machine 18" on the X. (just tossing numbers for you short table owning guys)

    I will probably catch a bunch of crap for this, but AVOID the non variable speed BP's.
    I cannot tell you how many times while learning this stuff, I've reached up and added or removed some rippems while running. I don't think you can do that with a belt and pulley model.
    Seriously, the variable speed head is the only way to go. You won't have to stop and dick with moving belts on pulleys. The only thing with the variable speed head, the machine must
    be running when you turn the crank. You have a high range and a low speed range. From there you just turn the crank. I will say 90% of the time, I'm in High.

    Another real nice thing to be on the hunt for, is a riser block for a bridgeport. They are cast iron and came in different heights. What happens, with tall stuff on the table, you end up with the
    knee all the way down and are fighting to have enough vertical clearance. I've come close once or twice when swapping cutters and drill chucks. I think a 6" riser would suit me nicely.

    DRO! Don't buy a tired as hell machine just because it has a DRO on it. DRO's are cheap and you will want X,Y and Z axis setups. Having a quill DRO is a cheapy thing you can add later too.
    Adding your own DRO is an excellent first project like I did. You'll learn how to use the dials and will learn to hate them REAL FAST! I pity the guys that don't have a DRO. Gluttens for punishment. We are not doing this stuff for a living, just need to be able to machine stuff occasionally with some sort of accuracy. In the old days, I was pig shit happy with a 1/16 of an inch, now if I'm within 5thou I'm ecstatic! As they say, "Good enough for the girls I go out with!"

    Vice - Don't pay up because a machine has some tired vice on it. Get with those guys in california and score a nice deal on a clean used Kurt. For the cost of a new import, you can get a nice Kurt.
    You are going to knick a vice SOMETIME! I haven't hit mine yet, but I did tick a parallel the other day and I'm still a little pissed. (Harbor freight has great parallels btw and priced on planet earth)

    If I was shopping, I'd be looking for a 1990's model with low time, in great shape. Plan on 3-5grand depending on tooling. Grab anything that's not nailed down and make it part of the deal. The machine is honestly the cheapest part to this machining stuff. I'm glad my tired old machine was free. With a little work, I've been able to tighten up my machine to work great for what I do. And I've still got new X/Y crossfeed nuts to go in it. I'm sure my screws are tired, but they are stupid money. If you are serious about CNC'ing a BP, you'll be junking those anyways for ball screws. So get decent stuff and sell your old screws to me!

    Powerfeed on the X at a minimum. The chinese have done well making cheap add on powerfeed kits these days. But if you do go CNC, things will get really weird and expensive. I'd think long and hard before converting a BP to cnc. Honestly answer your own questions about how often you'll really need a CNC part. Maybe a Tormach might be a better way to go? If you are only talking a few parts a year, send that shit out. The conversion is expensive and a fair bit of work. A good honest manual machine will always be worth owning.
    Last edited: Jan 31, 2021
    Larry$ and Robert like this.
  5. Jason

    Jason Gold

    ......and yes a VFD will make a non vari-head more tolerable... My VFD is hanging off the back of my machine, I haven't looked at in months.
    Now how this would interface with CNC is beyond my pay grade.
  6. DavidF

    DavidF Administrator Staff Member Banner Member

    I think the first rule of buying a used machine is to be patient. If looking at a Bridgeport, look for ones that have their ways chromed and not the early machines that were not hardened or chromed. Although if you want to try your hand at scraping ways....
    Belt drive or variable? Well I have no preference and tend to go a little slower on my feeds and concentrate more on chip load per tooth and reserve " high range" for tiny endmills with coolant.
    The $200.00 vises from China bay are great so save your money for other tooling and get one for starters.

    Or just buy a new precision Matthew's mill. I doubt you would have any disappointment.
    Until you put the first nick into the table anyways.... endmill pull out is a real $@^&$!
    dtsh likes this.
  7. Zapins

    Zapins Gold

    I've seen several pre converted bp cnc machines in near mint state for 6 to 7.5 k. Thats within budget if I wait till June or July to buy. I'd love a cnc mill. Basically I imagine it's like my 3d printer, just program it and watch it get to work.

    After dealing with my southbend lathe I want something with power that will not bog down and won't take me 5 hours to cut a simple part.

    I have a lot of large tool bits I scrounge from a flea market so it would be nice to use those with my machine. I'll have to ask you what mill to get to fit the bits.
  8. DavidF

    DavidF Administrator Staff Member Banner Member

  9. Jason

    Jason Gold

    This one is a BIGGIE! Personally I think making a bridgeport into CNC is a fools errand. You want CNC, buy a tormach. My neighbor has one, it's bad ass, but don't think for one second he won't hesitate to walk down the street when it's something large, simple and needs it done FAST. They both have their places in this world. For me at this point, I'm snug as a bug in a rug!
    I just feel bad for his neighbors. He runs his machine for hours on end and you can hear it in a closed garage 2 houses down.
  10. DavidF

    DavidF Administrator Staff Member Banner Member

    They're ok, but limited on travels. That's why I went with the pm940. Its friggin huge!!
    14" y 28" x and 22" z travel.
    Sure beats the lil go704 I have. Had a hard time using it for drilling anything mounted in the vise because of its limited z
  11. OMM

    OMM Silver

    I have a Bridgeport mill that is the four-speed pulley with high and low (eight speeds), it only has the 42 inch table with a 1 hp motor. (I believe they came 42, 48 and 60") over the years they have increased the horsepower. The 3 hp is more than you'll ever need on a manual machine. My 42 inch machine only has X travel of 24 inches., I try to keep it under 20 inches of travel as my ways a little bit worn in the middle. So the table does a little bit of a teeter totter on long cuts. It leaves a convex cut of 0.002" over a 20 inch span. This is not enough for me to worry about as anything I need that needs high precision I'll put it on the 20 inch surface grinder. For machining capabilities most of my life I used the 3 hp and I used a 2 inch three point facemill fly cutter. The cutter would take 0.100 cuts all day long in most material except for 4140. The R8 cullet is one of the most diversified and cheap holders. You can buy a whole new set of 10 for under $90. I do agree that a DRO is an absolute must especially in the X and Y. For the Z it's not really that important as your knee Dial is in 0.100" per rotation and the ways or acme thread doesn't usually see a lot of wear. But, when I replace mine I went with three axis DRO for the extra $70. My new DRO I believe ran me $350 USD.

    If I were to ever replace this machine (which I highly doubt I will) or if I was looking to buy a (new to me) used machine, this would be my list of requirements.

    -the real Bridgeport that works really good at a screaming discount. The resale is better.
    -3 hp
    -three phase 230v Motor or a 230 V/460 V motor that I could adjust the power leads in the pecker head to run from a Vfd
    -variable speed Reaves drive with obviously high and low gear changer.
    -60 inch X table. If you have the space.
    -manual lever lubricating system. They usually don't break down.
    -maybe X axis power feeder, but not a dealbreaker
    -virgin table/bed that's never been drilled/machined into
    -quill that still works and still has the handle on it. Usually the machinist smashes this off with his dead blow hammer accidentally.
    -comes with a vise and a lot of tooling
    -comes with a rotary table and or an indexing head and possibly even a big sine plate, a boring head and tons of cutters/drill bits.
    -a back of machine magnetic disconnect or manual disconnect.

    There are plenty of good deals out there. You just need to watch and jump.

    The machine I just described with all of it tooling I wouldn't blink an eye to spend 4 to $5000 USD. But if you can get all that for anything less, you're doing good. The machine I just described could easily in my area sell for $8000CAD or more at an auction. In 2002 the boss I was working for bought 12 new Bridgeports. The machinery installer told me that they were $20,000 apiece. Just after they were installed, the X and Y were replaced with ball bearing threads and a pneumatic R8 tool changer. I absolutely loved the machine with the 60 inch table and only X and Y DRO.
    Last edited: Feb 1, 2021
    Jason likes this.
  12. Jason

    Jason Gold

    Well said Matt. I think I had a good teacher!:D:p I have the 48" table and recently wished it was a 60" for a long milling operation. Not a big deal, I installed a fence in the t-slot using some hold downs and just slid my part. Again, good enough for the girls I go out with.;)

    I bet working on a brand ass new BP must be heaven!
  13. OMM

    OMM Silver

    Jason, you are one of the few that got a lot, for very little $$. But, from what I remember you had a lot of time moving and moving expenses. You were definitely in the right place at the right time with your pocketbook open.

    You will easily be able to sell everything you purchased for the same price or more in 10 years with 2 minutes of maintenance once a week.
    Jason likes this.
  14. Beaver milling machines are also worth a mention, by 1967 they were going to be selling 1000 units to the USA per year: http://www.lathes.co.uk/beaver/
  15. Jason

    Jason Gold

    You're right Matt, I got pretty lucky. The lathe was just the icing on the cake. It sure makes buying tooling easier to swallow. I still cry a little when I chip a carbide endmill. Once Zap finds his mill, he will be telling us he how doesn't know how he lived without one for so long. I'd love to give mine a lick of paint, but I still don't want to be without it for even a week let alone the month it would take me to rip apart, clean, fix and paint. I'm up to my ass in work right now anyways.:(
    OMM and Petee716 like this.
  16. Peedee

    Peedee Silver

    I use a Condor with a 48" bed, x and y DRO, completely ancient but does some serious metal munching when needed. Draw bar release is a PITA because I'm a short little **** but even at it's age it can take some nice precise cuts all the way through the travel.

    I'd like an X axis DRO but it's not a killer, I'm just too lazy to read dials

    Whatever you get a dull cutter/tooling will drive you mad! You can put 50hp through a dull end mill and it will still machine like sh^te.
  17. Jason

    Jason Gold

    Yeah, I gotta get up on my toes to smack my drawbar. Here's a suggestion... Get a longer brass hammer to hit that sucker!;)
    dennis likes this.
  18. dennis

    dennis Silver

    Brass? Surely you jest. Didn't you say earlier that you do not like Brass?

    You want an Everdur hammer. I'll send a Balsa head or two.

    On a more-serious note, the first casting I ever did was a brass hammer head. Lost foam, and I still have it 30 years on.
    Jason likes this.
  19. Peedee

    Peedee Silver

    I have a fancy for casting a copper mallet. as far as the draw bar goes it's like I've always said to my dad "I'm a Wiggins, if I want it to move it will move....."
  20. Jason

    Jason Gold

    I have a crappy brass hammer that belonged to my grandfather. Come to think of it, it's just one of the two things I got from that tight ass.:rolleyes:
    It was heading to the trash and I pulled it from the can. What a waste of 99yearso_O We have no children and when I'm gone, it's all going
    to the local cat and dog home.;)

Share This Page