just starting out and got a bridgeport!

as the title says i am an aspiring machinist. currently i am a mechanic by trade but have always been interested in machining! i recently got myself a bridgeport series 2 with a 5hp 3ph 575v motor. i picked it up from a machine shop auction for 300 bucks! everything still works, it has automatic feeds and came with R8 collets. the extent of experience i have only extends to what i learned in highschool on these machines. as im new to this im looking to learn as much as i can from the help of this forum and from the experience ill gain from this machine. my first hurtle is getting it home what are my options? and then my second hurtle is how do i power this thing? i was told at the auction from another machinist that i have a few options including a VFD, a rotary phase converter, changing to a 220/240v motor or a 3phase generator. the last one is pretty self explanatory to me but ive never heard of VFD's or rotary phase converters. if i was to change the motor would the machine still be able to keep up with the work load? sorry for all the questions just bear with me everyone starts out somewhere right!?

It is a tall tippy machine. Good to have a machine mover help. You got a deal at 300 so if you have to spend another 300 to get it home safe still a bargain.
You can lower the knee and take table way down to make it less top heavy. Crank the cross travel in tight to the collum. Some you can turn the down head to put the heavy side down.
You can hire a tow truck to lift it straight up / roll a trailer or a truck under it and then lower straight down, Crib in the base and chain it off so it can't tip. Then straight up and move the truck or trailer.

It is really a job for a machine mover.
Even with a mover if you should use a truck with a lift gate turn the Go Down lever as slow as you can move it because sometimes the start off is way too fast if you don't open the down valve as slow as you can.
*Other guys at the auction might help you find a mover.

Hire a small rollback truck if you dont have a pickup and car trailer.

Rotary phase converter is usually the best bang for the buck for larger manual equipment but you will still have 240 volt or whatever your input voltage is. A used step up transformer may be cheaper than swapping the motor.

Simplest powering would be a phase converter, just google them and there's loads of info and the right kind of info faster than asking here. You should end up dropping ~$200 or so for one to suit your needs. Also look up Bridgeport VFD conversion - lots of info there too - if you don't like changing belts that's the way to go and if you got the funds do that, changing the belt around is a pain.

a 5hp 3ph 575v motor.... Can electric shop get that down to 220 ? or is buying another motor due?

A lot of times equipment and big motors can be configured for different voltages by how the wiring is hooked up. This is the case on my knee mill. I don't know if this is the case for your motor...

I run a VFD on mine. I like it because I can vary the speed without changing the belt on the pulleys. For light duty milling this works fine. If you are doing heavy milling it would probably be best to change the belt. Look into the pros and cons of VFD vs phase converter to see what is best for you, either will work.

One more thing: make sure you use way oil and not grease on the ways and get some spindle oil for the spindle bearings.

Just a couple of things:

The 575VAC will be a problem! You're going to need a transformer to get the higher voltage. The easiest thing would be to find a 220VAC 3 phase motor to replace it. If you can't do that, you'll need a 5HP RPC and a 3 phase 220~575 transformer. Expensive! Except for low HP, VFDs and RPCs (rotary phase converters) don't change voltage for you.

You say the machine came with R-8 collets. The Series II did not have an R-8 spindle. That was Series II Special. The Series II had either a Kwik Switch or an NTMB spindle.
JR

I've got some 440v & a 575v machine.

Your first step would be to read up on PM about how to build a rotary phase convertor. This has been rehashed so many times there is a ton of info on it. The cheapest method is to use a surplus motor of the same size, or preferably one size up from what you want to run. (5HP idler for a 3HP machine, or a HP idler for a 2HP, etc). If you set it in the corner, put a suitable sheave or flywheel on the end, and start it with a pull rope (like old Briggs & Stratton lawnmower) you basically have a free convertor. You need a disconnnect and some wiring, that's about it. They get a little more complex and costly as you move up the convenience curve, adding a starter circuit, balance caps, etc.

On a machine such as a surface grinder that may have 3 or 4 interconnected motors & chuck of the same voltage but not much amp draw, it is usually cheaper to just add a transformer. If you change motors, all the starters need new heaters, and may need up-graded to a larger size; since when you cut the volts in half, the amps have to double. Sometimes even some of the wiring may need replaced to a larger size.

On a machine with a single motor like a mill, it is usually cheaper to replace the motor, or to have it rewired or re-wound at a motor shop for a lower voltage, and replace the heaters in the starter. Some motors can just be rewired with new leads brought out. For instance, a 440v motor can almost always be reconnected internally for 220v even if not all the leads were brought out originally.\

I have so many machines of various voltages that I use transformers. But that is probably not the best way to go for you starting out unless you foresee getting some more 575 machines, which are kind of common up there in Canada.

smt

@goldenfab thannks for the tip on the way oil i probably would have used regular oil! the plan was to use a flat deck trailer to move it so i guess i was right in choosing that to move it.
@JRIowa it could very well be a series 2 special, i could very well be getting more machines in the future but for the price i couldnt turn this thing down. does anyone have some excercises i could cut on the machine to get some practice?

One tricky thing is changing direction. Say you are milling straight at a shoulder long travel and then have to make a turn to the right or left going cross. It is a matter of snugging up table locks so the cutter rotation does not pull in the part and make a deeper place as the in-side corner change is made. Just takes practice on some waste material to get the hang of it.
Measure the free play in the lead screws (cross and long) and note that on the machine or on a nearby map to know how much you may have to adjust your feed lengths for screw error. That can save an in-process measure because you better know what to expect. I think it is good to pick up at least one end mill holder , perhaps a 3/4 (or 1") and with a double set screw fix, have an end mill that will not pull out when you have a heavy job. It is a sadpoor lesson to scrap a part because a collect held end mill pull out.

You wiil (may) soon learn climb milling with breaking an end mill with sucking in the part with the pull of the cutter.

You may learn to tram the head so may need an indicator

End mill cutters are best with being Shave you finger nail sharp. Good to buy a few brand new end mills to know how a sharp cutter should cut.

thanks for the tips guys! i have a few dial indicators, mics and other measuring instruments im big into building engines so ive got lots of practice measureing tight tolerances! lol what are some basic end mills i should be looking at? unfortunately i didnt bid on any end mills at the auction as i didnt think i would be able to afford a machine all the others sold for a little over 2k each and my machine was auctioned off very last i just threw in a 300 dollar bid with 1 minute on the clock and got lucky i'm picking the machine up this tuesday ill be sure to get some pictures of it and maybe you guys can help me get more info on it like manuals or anything else useful. is there anything i should look out for on older machines?

they have fork lift services where ill be picking it up, i was planning on getting it home with a double axle car trailer. and i do believe the head turned. what do i need to get the head to turn? allen keys or just like a regular ratchet set? only thing ive ever done is change an end mill and collet...

QT: [anything i should look out for on older machines?]
The proper way to change gears with a little hand turn of a spindle or a belt can often make things mesh better.. It can be easy to break something and expensive to fix things. You may have been lucky all the mill interest guys were done bidding or there is an unknown factor that made your mill low priced. Slop in the lead screws is a factor but I have run production rate good parts on sloppy machines. Quill down feed anothr factor good to check that is OK. Put out of gear and see the spindle turns (feels) good.

oooh yea i know they can be expensive thats why im trying to be as careful as i can with this, is there some write ups on doing that sorta thing?

another thing i forgot to ask is when i do finally get the thing up and running with end mills and all how do i got abouts selecting a speed? do i base this off the material im cutting the end mill i use or the type of cutting im doing?

For steel the old rule was so you can just (eyeball) make out the flutes. For aluminum much faster.

Speed (RPM) and chip load, basically the number of flutes and feed per revolution so each tooth has what it might handle.. and then consider surface finish needs and how good the set-up.

Yes, that (old rule) is not proper because you can find speeds and feeds so easy on the net.
We had pocket slides to find speeds and feeds.

Perhaps you may wish to re-do heads for flat. Good then to find a junk (scrap) head and mill it a number of times with checking each time..you may find that job a real challenge as it takes a very good mill and the way you hold down the head can distort it so when released it may change. No, I haven done heads but have done some long work and it can be troublesome.

i was taught about feed rates but never about RPM the teacher always had it setup for us and all we did really was set our material in the vice and cut away. I cut a V-block and for my final project i made a miniature T-34 tank paper weight thingy lol it was pretty neat and i still have it some where but thats about all the expirence i have on the thing. ive used fly cutters and few other smaller end mills but my experience is very limited. would i be correct in saying use a slightly faster feed rate for the bulk and a slower feed rate for the final finish?

JRIowa said:

...The 575VAC will be a problem!

Click to expand...

Probably...but it depends where he's going to run it. In Canada 600 volt service is very common in industrial buildings. Last shop we were in--over 20 years ago--had 600V primary service. Step-down transformers were installed to get down to 120/240...

this will be going into my parents shop, they have a farm with a 6 car garage and plenty of space for it lol but they only have regular house hold voltage. they wanted to get the garage wired for 220v though so what ever is easiest/cheapest that being the input voltage.

Most services have two 110volt legs so 220 is there for a dryer or kitchen range. Yes, still single phase. Easily converted to 3phase. Bridgeport motor 250 to $400 can be had.