Machine Tool Suggestions

[JohnFogarty]

Hello all,

Recently I've been trying to plan for the future tool purchases I will be making for 4901 in the upcoming pre or post seasons.

Here's a little blurb on what I have space and tool wise to work with currently. 4901's build shop is a small project shop off to the side of the main University of South Carolina Engineering Machine Shop. The team gets to use a little less than 1/3 of that space for building. A space that can accommodate maybe less than 10 people working simultaneously. Other than that we have an office in the machine shop and then space for non-machining build meetings throughout the college of engineering.

On to the tools. We currently have a JET tabletop band-saw in our project shop, a small drill press, a combo 6" belt/disk sander, and an assortment of hand operated tools (all the normal stuff wrenches, screwdrivers, pliers, files, etc.) (drills, impact gun, reciprocating saw, circular saw, a Dremel, and a few air tools as well).

Our main machine shop (which we have somewhat limited or no access to during normal meeting times, which could change this year) has all the goodies. By that I mean, several manual operation mills, several manual operation lathes, a large vertical band-saw, a horizontal band saw, 2 older 2.5 axis CNC mills, and 2 older CNC lathes, an arbor press, and a welding setup, a sandblasting machine (clueless to how it works), and grinding/sanding set-up. Also the CEC has a water-jet and a 3D printer in another building we could use...potentially but the turnaround time is really long, something like 2+ weeks depending on the operator's time constraints, I wish I knew/and was allowed to run the water-jet because then things would get done. So all in all if we had unlimited access to those machines and I had a mentor, or my own knowledge of how to run them all proficiently we'd be in business.

However at this point things don't look they will be changing very soon. So I was beginning a search for smaller tools to start adding to our project shop setup. For example...

this mill
https://littlemachineshop.com/products/product_view.php?ProductID=4981&category=138780768 3

building this CNC router or buying another one (with Bosch FMS instead of 80x20 (don't know how easy that would be yet.)
http://www.kronosrobotics.com/krmx02

and this lathe
https://littlemachineshop.com/products/product_view.php?ProductID=3877&category=127179930 6

The idea of buying or making the router is that I could potentially make it large enough to do our small aluminium sheet work for example; gussets, gearbox plates, gearbox mounts, etc.

I actually was turned to the idea of mini machine tools for use after seeing the smaller machine tools that Team 180 has in their pit, which we made good use of at the Orlando Regional this year before elims. I was wondering if the community had any good suggestions on machine tools that I should look at instead of the above tools and what things I should look for in terms of what NOT to buy. Say I fall into a pit with $7-8K in it what could I get with my money.

[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!

[magnets]

It depends on your team and if you only have 120V in your shop.

Personally, I wouldn't buy any Grizzly products.

I've used an RF-45 mill, (it might be the same as the PM-45, but not sure), and it's actually pretty good, especially for the price.

Used is definitely a good option too. If possible, try to get it from a corporation or machining center that's taken good care of it. We've reached out to local businesses to get a 1960's bridgeport and a 1960's south bend lathe. These are two of our main machines during build, and we got both for under $2k.
If you do buy used from a company, ask if they'll give you some old tooling. These places typically throw out endmills after they've been reground to too small of a diameter, but they still work very well.

[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.

[Travis Schuh]

My experience with the 7x12 lathe that you have listed is that it it is not good for cutting aluminum. The machine is not very ridged. You could probably get away with aluminum if you were just making spacers, but I wouldn't trust it for shafts. This lathe's strong points in my opinion are with plastic. With a skilled operator, it would do fine at making plastic spacers. Would certainly take longer than with a regular tool room lathe.

If I was to use this lathe more seriously, I would spend the time to figure out how to hook a set of calipers up as an indicator on the carriage, they show using the DRO on the cross slide for the axial direction, however the cross slide really isn't suited for that.

[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.

[DampRobot]

Originally Posted by magnets

Personally, I wouldn't buy any Grizzly products.

While Grizzly isn't exactly world renound for their quality, I wouldn't go this far. I learned on an older Chinese made Grizzly lathe (13x40 IIRC, but could be totally wrong). It was a solid, rigid machine, and when adjusted properly had absolutely no runout issues. When the kids crashed it, it broke a few times, but nothing that couldn't be fixed (or was because of bad build quality).

That said, when I recently got to use a 60s era American made lathe (a Feeler, I believe) I was pretty seriously impressed by the build quality and how good it felt to machine with it. Old American made machine tools have a great reputation for a reason, but that doesn't neccesarily make cheaper Chinese products (like Grizzy) a waste of money.

[artdutra04]

There is a Sticky thread in this forum that has TONS of recommendations: http://www.chiefdelphi.com/forums/sh...d.php?t=115165

[DonRotolo]

Originally Posted by JohnFogarty

building this CNC router or buying another one (with Bosch FMS instead of 80x20 (don't know how easy that would be yet.)
http://www.kronosrobotics.com/krmx02

I built a 27x50 version of the KRMx02 and I find it to be just about perfect for FRC type fabrication of aluminum and other materials (Polycarbonate, wood, plastics).

There are a few minor changes I'd make if I built a second one, but overall I am very happy. Let me know if I can answer any questions.

If you plan on cutting aluminum, be aware that you will require compressed air to manage the machining chips and some kind of coolant system (such as a mist cooler)

Also must haves include a shop-vac for dust management, a computer to run it all, AND an investment in time to learn how to operate the thing. I guarantee you will break bits if an unskilled operator feeds it G-Code. The learning curve is not that steep.

[JohnFogarty]

Originally Posted by artdutra04

There is a Sticky thread in this forum that has TONS of recommendations: http://www.chiefdelphi.com/forums/sh...d.php?t=115165

That's odd. I don't know why I couldn't find that when I searched.
Thanks for all the suggestions.

Don I'll be sure to contact you if I have any questions on the KRM related stuff.