Machine Tool Suggestions

[protoserge]

I'll start by saying the obvious comments from the forum first

1) If you can fit a Bridgeport knee mill, do so.

2) If you can purchase a well-cared-for used Bridgeport, do so.

3) Are you sure you can't fit or buy a Bridgeport knee mill?

4) Read the many threads already in place. Cory is one of the resident experts on this subject.

Now, on to my comments...

First, I'm not a fan of machine tools in the pit. I don't like the idea of undersizing machine tools to be mobile when it sacrifices the working envelope. I also don't like having a huge liability (thousands of dollars of equipment) that could be stolen.

5) I am a huge fan of the Bridgeport knee mill. I'd love to have one, but I move around quite a bit, so I bought a PM-30MV-L for personal use.

6) If you can't fit or buy the Bridgeport, I'd recommend getting a bigger mill than the LMS HTMM. It is suitable for very small projects. For $1800, you can get a PM-30MV-L from Quality Machine Tools. For $2400, you can get a PM-45. Both of these mills are larger and will be more versatile. For the same price as the HTMM, you can get a G0704.

7) You aren't building a space shuttle. The quality Chinese-made mills work well and are great for FRC applications. Be sure to disassemble, clean, and lube any new Chinese mill and you'll have a smooth machine. Unfortunately, this is where you learn where the cost savings come in (Bondo, hastily-done castings, etc.).

8) You might be better off with the LMS 8.5x20 lathe, but the lathe you identified is well-regarded. The 7x12 is the same manufacturer (SIEG) as the Harbor Freight version of the same dimension, but I believe LMS has higher quality standards.

9) Did you ask LMS if they will sponsor your team? Maybe they will cut you a deal

10) In any case, get the biggest that you can fit in the space and be sure to budget about $4-5k for quality tooling. You can get cheap endmills - I've had good luck with the $65-80 16 count set from Grizzly on our FRC team's G1007 (not recommended - round column), but they don't get as much use as the quality endmills in the Haas or Bridgeports.

Good luck!

[JohnFogarty]

Important to note. I only have access to single phase 120V power in the project shop. Something I don't think I can get changed.

Since my desk at Rexroth is directly next to about 8 different knee mills of various manufacturers (Bridgeport, Jet, ACRA). I can firmly say I cannot fit a knee mill in our shop. (unless the shop engineer says I can get rid of one of the huge bulky wooden tables against the wall of our work area.

This being said we have about 5 knee mills in the main machine shop (I don't know that they all work)...that we just can't access all the time. We would have to have some graduate student mentors who needed access to the machine shop as part of their research so that we could access it at all times. We're working on getting that...we just haven't got it yet.

That PM-MV mill might work as well as the RF-45. I'll have to take some measurements of the space I've been planning this for. I was actually looking into the RF on CNCzone and practical machinist to see what people had to say about it.

I haven't asked LMS yet. I will however move forward with the idea of asking them to though.

[Andy A.]

Originally Posted by JohnFogarty

I was actually looking into the RF on CNCzone and practical machinist to see what people had to say about it

The Rong-Fu 45 is fairly well regarded as a quality small mill. It comes will all the limitations of it's light weight, but it's well made and as long as you stay within it's operating envelope it'll produce fine cuts. I believe it's also a common base for CNC conversions, so there's probably a great deal of aftermarket support should you choose to go that route in the future.

However, the catch is that the model has been knocked off by every other 'machine tool' manufacturer in China and, as a result, there are a lot of XX-45 mills out there. Some are great, some are bad. Some are really really awful. Unfortunately it can be hard to tell prior to purchase, so do your research and try to avoid deals that seem too good to be true.

[sanddrag]

For what it costs, I'd never buy that 7x12 lathe. Instead, look into the LatheMaster 8x14 or the Harbor Freight 8x12. They're actually the same machine (same length, actually 8x14), but Harbor Freight measures with the chuck on, when standard convention is between dead centers in the spindle and tailstock.

I've had the Harbor Freight 8x12 for 8 years, and it's easily twice the machine of a 7x12. It's actually my prefered machine over a worn out 1961 Logan 11x24 we have. You can do real machining work in aluminum and even steel on occasion, and I can hold a great tolerance too. I've drilled 1" holes and turned 4" diameter with it. Try that on a 7x12... I've never needed to adjust the gibs either. The only things I've had to do in 8 years other than oil it were replace one bolt I broke, and crimp new connectors on a couple wires.

The lathemaster includes more accessories such as the 4-jaw chuck, faceplate, steady rest, and follow rest. In my 13 years of machining for FRC, I've only once wished I had a steady rest or follow rest, and never needed a 4-jaw chuck or faceplate. The Harbor Freight doesn't include these items, but you might be able to buy it with a 20% off coupon.

The 8x12 can be lifted by two strong people. I have mine sitting on top of a Harbor Freight 44" 13-drawer tool box that I highly recommend.



There's several other threads here on Chief Delphi on machine tools in this price range if you search.