Vertical Mill for FRC

[Jay H 237]

Another vote for finding a Bridgeport, and if you do you'll become spoiled!

A Bridgeport was a staple of machine shops years ago, and still are in some cases for one off jobs, but with most stuff going CNC they are becoming easily available as shops upgrade if you look hard enough. I just got one donated (tax exempt 501c3) that was well taken care of and gone over once a year. It was no longer needed and the company was willing to take the tax write off, pic of it below after I unloaded it in it's new home. Look hard enough and get out the word you're looking for one and chances are you'll find one. Being maintained this particular one had little backlash and good ways. Takes a standard R8 collet, a complete set of collets was included too, in addition to being equipped with a DRO.

Depending on how you set up the motor this one is good from 208v 3ph to 480v 3ph.

The only cost I had was $210 for a roll back. The pallet and banding was free from work.

[vertigo]

Thanks again for all the advice in this thread. I wanted to necro it to provide an update. After taking stock of our budget for this year (trying to go to two regionals for the first time), the space available in our shop, and scouring Craigslist all summer, we have decided to go with the G704 from Grizzly. While it is certainly not a Bridgeport, I think having this will be better than having nothing at all. The fact that there are resources that describe how to convert it to a CNC is also a huge bonus.

http://www.grizzly.com/products/Dril...th-Stand/G0704

Now for my next question. Bits and accessories! What mill bits would you recommend to start off with? Brands? Any additional accessories we should consider? Any good guides for general maintenance or best practices? Thanks again!

[asid61]

Originally Posted by vertigo

Thanks again for all the advice in this thread. I wanted to necro it to provide an update. After taking stock of our budget for this year (trying to go to two regionals for the first time), the space available in our shop, and scouring Craigslist all summer, we have decided to go with the G704 from Grizzly. While it is certainly not a Bridgeport, I think having this will be better than having nothing at all. The fact that there are resources that describe how to convert it to a CNC is also a huge bonus.

http://www.grizzly.com/products/Dril...th-Stand/G0704

Now for my next question. Bits and accessories! What mill bits would you recommend to start off with? Brands? Any additional accessories we should consider? Any good guides for general maintenance or best practices? Thanks again!

You might regret the Grizzly in the future. I've found that being able to take large cuts, extra work envelope, and just the sheer size of a Bridgeport is hard to beat. Although recently I have been looking into horizontal mills as lathe/mill combos.

That being said, for tooling, you will want at least:
-3/16" end mill (for milling 10-32 and 1/4"-20 clearance slots)
-1/2" end mill(for general purpose milling)(get a double-ended one of these)
-3/4" (for making existing holes larger)
-Small boring head (for boring out holes for press fits)LMS has it
-R8 Collet set for 1/16", 1/8", 1/4", 3/8", 1/2", 5/8", and 3/4".
-Taps, for 4-40 through 1/4"-20 in all the normal imperial sizes. This depends on what your team does, but those are the ones I've used.
-Drill chuck for at least up to 3/8" drils (do not use this for endmills)
-Drill set. Numbers and fractionals at least, letter drills if you can get them. Buy shortish drills if you can, as you will probably rarely need a Jobbers size. I don't think in 3 years I've ever used anything longer than 2", and most of the time it's <= 1".
-Set of single-flue countersinks. Get 2 or 3 sizes. Fantastic for deburring holes quickly.
-1/8" thick set of parallels. You need several sizes.
-Vise. Get a quality vise, or at least one designed for machine work. A regular driling vise will not work. We have a vise with angles markings on its base, which is very useful.
-Deablow or soft face hammer to seat stock on the parallels.
-Other stuff that I've missed in this list.

Measuring tools are an entirely diferrent story. I'm going to list the ones I think you can get by on.

-6" calipers. Get good ones. Mitutoyo or Brown and Sharpe are good brands, but I prefer the former as they are consistently good across the board. Digital ones are good because you can reset the zero to whatever you like. Mitutoyo digital calipers are around $50 on ebay.
-12" ruler. Get one that has divisions in the 0.01" range, not a regular one. Better would be a 12" caliper.
-If you get a 36" ruler you can make side 2x1s for a WCD.
-Vise stop. Very useful to take stuff out for the vise to measure it.
-Small clamps. I'm partial to these, as I use them to clamp multiple plates together often, and they're strong. Other types will work.
-Edgefinder. Spend $15 on ebay and get yourself a Brown and Sharpe or other band-name version. These determine quite a bit of your tolerances.
-Test indicator. Get the type that looks like this. They're good for finding the center of holes and aligning the vise to the head.
-Electronic protractor. Good for making angles. It will read 90* when on a wall. You tilt it to find angles.
-Combination square.
-Scribe (Like a pointy metal pencil).
-Sharpies.
-Scientific calculator (just have one on hand. An iphone will do).

A DRO would be a great addition, but they are expensive. However, even a cheap DRO is better than none.

I have heard that 1-2-3 blocks are good to have, as well as v-blocks, but I have never used them for our parts. There was never any part big enough ot strange enough to justify using them. However, you might want to pick up a clamping set anyway, because your vise will likely be smaller than ours so you might need the clamps.
I used the above the most out off all the ~$6k of machining-specific tools the woodshop teacher has.
I will edit this later to include more stuff, but I think I got the basics.

[James Tonthat]

Originally Posted by asid61

...Mitutoyo digital calipers are around $50 on ebay...

Your result may vary, I've heard of a lot of these being fake. Keep in mind a new set of Mitutoyo digital calipers go for around the $120 range for a 6" and closer to $190 for a 8".

[asid61]

Originally Posted by James Tonthat

Your result may vary, I've heard of a lot of these being fake. Keep in mind a new set of Mitutoyo digital calipers go for around the $120 range for a 6" and closer to $190 for a 8".

True, but many of them come with the certification. If you have the money, new is better, but you can open an Ebay case if it's fake.

[Qbot2640]

Originally Posted by James Tonthat

Your result may vary, I've heard of a lot of these being fake. Keep in mind a new set of Mitutoyo digital calipers go for around the $120 range for a 6" and closer to $190 for a 8".

Don't cheap out on calipers. You will be amazed at how often they are used, and while there are many very capable brands - the good ones are smooth and just feel perfect. We got a "medium level" 6" caliper last year and the kids use them constantly. But they are no where near as nice as my old, beat-up Mitutoyo, Brown and Sharp, or Starret models.

[FrankJ]

One the other side of the fence. I buy Harbor Freight calipers for general use. They are noticeably not as nice as Starret or Mitutoyo. But they are also a 10th of the cost. I can loan them out without requiring a first born as collateral for their safe return. Somebody mikes a moving grinding wheel, I can laugh.

[protoserge]

Originally Posted by FrankJ

One the other side of the fence. I buy Harbor Freight calipers for general use. They are noticeably not as nice as Starret or Mitutoyo. But they are also a 10th of the cost. I can loan them out without requiring a first born as collateral for their safe return. Somebody mikes a moving grinding wheel, I can laugh.

I really agree with Frank on this. I bought the $17-20 pair of Neiko 6" calipers on Amazon. You can get 6 of those or one Mitutoyo. If they break from misuse or accidents, it's less costly to replace.

FRC isn't ISO 9001. Hobby mills and cheap calipers get the job done just fine.

[asid61]

We use two calipers. One is in the machining tool box, where everything is nice and sorted and clean (and I like to keep it that way), and the other is in the communal toolbox, where things get bumped around with the rulers and the like. Both are in their own boxes. However, even after ~5 or 6 years of constant use, the ones in the communal toolbox are still accurate to +- 0.001", or better. Both are Brown and Sharpe dial calipers bought for about $100 each years ago by one of our mentors. Good tools last, as long as students are told how to use them properly.

[MichaelBick]

For manual machines, we really like the hss end mills from latheinserts.com.