Uses of a Machine Shop and Equipment

[koreamaniac101]

Hi, I'm the founder of my robotics team that plans to start its rookie year in 2016. We just got access to our local universities machine shop with:

• Lathe
• CNC Mill
• Vertical/Horizontal Bandsaw
• Cold Saw
• Surface grinder
• Drill Press

My new mentors are wondering why would need all the machine shop equipment for. Could any give specific examples of what you would use each of these equipment for? If you could link pictures of specific parts made from a Mill or Lathe, that would be great too.

[JDGallagher]

We use our lathe to make shafts for our custom gearboxes, intakes, and elevator roller assemblies this year. The lathe was only really necessary to cut the grooves for retaining rings. We used a mill to make our elevator rails (which we could have used a drill press for) and our intakes, which had weight reduction hole patterns and slots for the motor to mount to so it was easier to tension chain. I can upload pictures or CAD files of the parts later today.

[carpedav000]

Alright, here's what I've got:


CNC mills are beautiful for sheet metal fabrication, if you have someone who is willing to cad.

Lathes can be used to shave material off of axles/shafts that are too wide. They can also be used to tap or drill holes into axles/shafts.

Horizontal/vertical band saws are mainly used to make simple cuts (i.e.. Cutting channel to length, making simple sheet metal/polycarbonate components, etc.)

Drill presses are good for making holes that don't have to be very precise (prototype parts, for example)

Surface grinders can be used to remove sharp edges/burs from material that has been cut

Cold saws (from what I understand) are basically fancy chop saws, which can be used to cut material (channel, HDPE blocks) to length.

[R.C.]

Why would you use cnc mills for sheet metal fabrication? Cnc lasers/routers and water jets are way more suitable for sheet metal fabrication.

You'd rather use the cnc mill for stuff like tubing and solid milled parts.

[carpedav000]

Originally Posted by R.C.

Why would you use cnc mills for sheet metal fabrication? Cnc lasers/routers and water jets are way more suitable for sheet metal fabrication.

You'd rather use the cnc mill for stuff like tubing and solid milled parts.

I am assuming that they don't have a laser/water jet cutting sponsor and that they only have access to what they have in shop.

[Joe G.]

Originally Posted by carpedav000

I am assuming that they don't have a laser/water jet cutting sponsor and that they only have access to what they have in shop.

I think the broader point that RC and Chris are making is that while a mill can perform precision cuts in sheet material, it is not the correct tool to do large scale "sheet metal" work in the conventional sense, and that with this resource set, a predominantly sheet metal robot would be a poor choice. The CNC mill works much better with a fabrication approach centered around extrusions, small gussets, thick, heavily pocketed plates, and complex parts milled from solid than a series of thin sheet parts, especially since you don't mention having a precision brake to do bends either.

[Alan Anderson]

Originally Posted by R.C.

Why would you use cnc mills for sheet metal fabrication? Cnc lasers/routers and water jets are way more suitable for sheet metal fabrication.

Lasers and waterjet cutters are not on the list of available machines.

[Kevin Sheridan]

Originally Posted by Alan Anderson

Lasers and waterjet cutters are not on the list of available machines.

Thats why RC recommended using the CNC mill for tubing and solid parts

[R.C.]

Originally Posted by Alan Anderson

Lasers and waterjet cutters are not on the list of available machines.

I understand that but in no way does a cnc mill beautifully makes sheet metal parts...

Also why would you recommend the cnc mill to make sheet metal parts if a brake isn't on the list? I guess you can make just flat parts but at that point you might well just buy the gussets from vexpro or other vendors.

I feel the team here needs to understand what machines they got and how to combine their machining capabilities with cots components. We have both a cnc mill and router in house. We rarely produce true sheet metal parts (bent) due to the fact we can't consistently bend the parts.

[Monochron]

Originally Posted by R.C.

I understand that but in no way does a cnc mill beautifully makes sheet metal parts...

Also why would you recommend the cnc mill to make sheet metal parts if a brake isn't on the list? I guess you can make just flat parts but at that point you might well just buy the gussets from vexpro or other vendors.

I feel the team here needs to understand what machines they got and how to combine their machining capabilities with cots components. We have both a cnc mill and router in house. We rarely produce true sheet metal parts (bent) due to the fact we can't consistently bend the parts.

Would smaller (say roughly 1' x 1') sheet metal parts be appropriate for a CNC mill? Something like a side support on a manipulator or shooter? I ask because our team may be building a shooter during the offseason and we were hoping to use a CNC mill to cut a structure out of sheet metal.

[R.C.]

Originally Posted by Monochron

Would smaller (say roughly 1' x 1') sheet metal parts be appropriate for a CNC mill? Something like a side support on a manipulator or shooter? I ask because our team may be building a shooter during the offseason and we were hoping to use a CNC mill to cut a structure out of sheet metal.

You could, the machine can do it , all I'm saying is it shouldn't be the workhorse for sheet stuff. Ex: Our Router should not be used as a mill and vice versa.

Also the sheet can be any size you want, that's dependent on your bed travel. Without knowing your machine and setup I can't give you a good answer.

On the same note, you should just find a local guy and work with them to help you cut your sheet. Who knows they might do it free and help with the robot build season. Quick google: http://www.yellowpages.com/research-...er-jet-cutting

Unsure if any of those are in range.

[RoboChair]

Originally Posted by R.C.

You could, the machine can do it , all I'm saying is it shouldn't be the workhorse for sheet stuff. Ex: Our Router should not be used as a mill and vice versa.

Also the sheet can be any size you want, that's dependent on your bed travel. Without knowing your machine and setup I can't give you a good answer.

On the same note, you should just find a local guy and work with them to help you cut your sheet. Who knows they might do it free and help with the robot build season. Quick google: http://www.yellowpages.com/research-...er-jet-cutting

Unsure if any of those are in range.

A mill is perfectly able to handle sheet if approached right, about half of all the sheet gussets on out robot were made on a CNC Router(and is by far one of the least stiff machines ever). It just takes some doing. A water jet or laser would be best but some times we need a part NOW.

[protoserge]

Originally Posted by Monochron

Would smaller (say roughly 1' x 1') sheet metal parts be appropriate for a CNC mill? Something like a side support on a manipulator or shooter? I ask because our team may be building a shooter during the offseason and we were hoping to use a CNC mill to cut a structure out of sheet metal.

You won't learn anything without trying. I would focus on the best method of workholding. This is where I see the most issues. Plan out the workholding and keep it safe. What thickness material do you plan on using? You definitely want to take light cuts to avoid digging into the sheet. I think this is the most risk of a good part yield.


OP,

Your machine shop access sounds great! You will find out how to use the machines in due time. Since you are a rookie team, I would suggest starting with a KoP or Vex Drive base and focus your energy on game piece manipulation (don't forget to consider active intake of game pieces) and scoring.

A simple example I can think of is an active intake wheel for a tote. You could:

1. start with a box tube,
2. drill a hole for a bushing (drill press or mill, depending on accuracy required),
3. press the bushing in (shop press/arbor press),
4. turn down an aluminum shaft to the appropriate length,
5. mill a keyway or broach a keyway (or use a hex shaft that could be turned round to fit in the bushing),
6. mount a drive pulley with a key,
7. drill holes in the end of each end of the shaft to mount machine screws to hold it all together (lathe),
8. machine a motor mount bracket (mill),
9. drill mounting points on the box tube for the motor mount bracket (mill),
10. become amazed at what you can do with such a shop!

The surface grinder is something I don't think you'll ever use, but if you needed something flatter to within a few tenths (0.000[x] inches) that would be your tool.

[Andrew Y.]

Non technical comment/question. Are your mentors non engineering mentors?

[koreamaniac101]

Originally Posted by Andrew Y.

Non technical comment/question. Are your mentors non engineering mentors?

Yes and No. We have an engineering mentor, but he is a Civil Engineer. Our other mentor (we have 2 right now) is a Non-engineering mentor. The local university also is possibly letting a someone from their Engineering and Physics department to mentor us, but we still have to finalize the details