buying a lathe?

[RoboChair]

I know some people will be giving me flak about this, but seriously consider this one
http://www.harborfreight.com/7-inch-...the-93212.html

Now before we start a flame war here, I want to mention the pro's and con's.
The pro's
Small easy entry machine
Handles FRC shaft work just fine
Can be equipped with a dial read out on both axes for around 50 bucks
With a dial read out this lathe can hold 0.001" no problem(without pushing it)
It comes with more set up tooling than you will need
It is going to have a hard time severely maiming the operator

The con's
It is really only useful for Aluminum and plastic, steel takes some TLC to turn
It does require more basic maintenance more regularly
You are going to have a hard time doing large stock
Most of the extras it comes with are difficult to work with or will not last very long

I have used this exact model lathe to make parts for our competition robots and it is a very serviceable machine for smaller parts. If 1678 had no lathe and we could buy one of these and some choice extras on sale I would do it in a heartbeat.

[FrankJ]

Originally Posted by RoboChair

I know some people will be giving me flak about this, but seriously consider this one
http://www.harborfreight.com/7-inch-...the-93212.html

....

The 7x10 & 7x12 lathes are mostly made in a couple of factories in China. Sold under a multitude of brand names. Actually not a bad choice for small work. Active hobbyist community that offers many improvements & support. Little machine shop has repair & upgrade parts. (You will be replacing the plastic spindle gears soon after you start using the lathe) I would go with the longest bed I could afford. The 10 in bed is really too short. The 12 in one is actually about 4 in longer due to differences in the way they are measured.

Little Machine shop 7x14 on sale.

You don't need 3 phase power for the smaller mills & lathes.

Mr Forbes: Our South Bend 9 in is a mid 30s vintage. It has the single lever quick change gear box.

[pmangels17]

Also, just a general tip. For almost any FRC turning work, and especially with (sometimes impatient) students (like me) running the machine, a three-jaw self-centering (standard 3-jaws usually have this) chuck will be way better than any independent-jaw chuck you can find. Sure, they might let you turn off-center work, and can be a bit more precise, but getting everything aligned is a huge pain, especially when most of your cuts will probably be facing operations or on-center operations.

[Chak]

Thanks for everyone's response!
Our budget is $2000. We don't have a machining mentor, so I think our coach is more comfortable buying new. It looks like our choices are one of the around $1000 benchtop lathes like the ones at Harbor Freight or Little Machine Shop + tooling. Anyone have advice/warnings/experiences with these lathes?

Btw, Little Machine Shop looks like a great resource, with their tips and guides. Looks like I have a long Thanksgiving Break ahead of me for research!

[RoboChair]

Originally Posted by Chak

Thanks for everyone's response!
Our budget is $2000. We don't have a machining mentor, so I think our coach is more comfortable buying new. It looks like our choices are one of the around $1000 benchtop lathes like the ones at Harbor Freight or Little Machine Shop + tooling. Anyone have advice/warnings/experiences with these lathes?

Btw, Little Machine Shop looks like a great resource, with their tips and guides. Looks like I have a long Thanksgiving Break ahead of me for research!

Little Machine Shop is a good place to look to see most of your options. In terms of tooling up a smaller lathe like that you can PM me and I can start working with you on a list of tooling for your needs.

[protoserge]

Look at the G0602. It has a good reputation. I would get a larger lathe before the LMS variety.

Quality Machine Tools has a good reputation for service and customer support: http://www.machinetoolonline.com/PM1030.html or http://www.machinetoolonline.com/PM-1127-VF.html would be a good choice.

Don't buy a used one unless you consult someone who knows what to look for. A large number of old "good" lathes will be nothing more than a pile of headaches. I picked up a South Bend 10L and sometimes wish I hadn't since it needs about $1500 in work. That being said, when you find one in great condition that has been cared for, they will outlive you.

[Chak]

Originally Posted by protoserge

Look at the G0602. It has a good reputation. I would get a larger lathe before the LMS variety.

Quality Machine Tools has a good reputation for service and customer support: http://www.machinetoolonline.com/PM1030.html or http://www.machinetoolonline.com/PM-1127-VF.html would be a good choice.

Thanks, these machines do look better. However, the lathe itself is about $2000, and these would certainly exceed our current budget once tooling is included. Are these bigger lathes good enough to justify exceeding our budget? If they're way better than the LMS variety, I think our budget is not dead set.

[AdamHeard]

Originally Posted by Chak

Thanks, these machines do look better. However, the lathe itself is about $2000, and these would certainly exceed our current budget once tooling is included. Are these bigger lathes good enough to justify exceeding our budget? If they're way better than the LMS variety, I think our budget is not dead set.

Yes, especially in the price range you're in each additional dollar will add a lot of value.

I'd find a way to make another few grand if possible (or skimp on tooling initially) in order to get a better machine.

[protoserge]

The only tooling you really need is some 3/8" high speed steel (HSS)/Cobalt blanks, and a parting blade. A boring bar would be nice as well, but you can make one with some round stock and a small 1/8" or so HSS blank. One of the quick change tool sets should have all of the holders included. Learn how to grind and all you need will be blanks, gages (for checking tip geometry), and a bench grinder.

[R.C.]

Originally Posted by protoserge

The only tooling you really need is some 3/8" high speed steel (HSS)/Cobalt blanks, and a parting blade. A boring bar would be nice as well, but you can make one with some round stock and a small 1/8" or so HSS blank. One of the quick change tool sets should have all of the holders included. Learn how to grind and all you need will be blanks, gages (for checking tip geometry), and a bench grinder.

I recommend going indexable tooling over the HSS/Cobalt blanks any day. Indexable is way easier to maintain and you just replace the insert over regrinding or replacing the too.

[protoserge]

Originally Posted by R.C.

I recommend going indexable tooling over the HSS/Cobalt blanks any day. Indexable is way easier to maintain and you just replace the insert over regrinding or replacing the too.

While this is true, I am stating that is all they *need* since they are on a budget.

[Cory]

Originally Posted by AdamHeard

Yes, especially in the price range you're in each additional dollar will add a lot of value.

I'd find a way to make another few grand if possible (or skimp on tooling initially) in order to get a better machine.

To elaborate, to buy a new, reasonable quality lathe that will last (something in the 13x40 range), you're looking at $5,000-10,000. Ideally you'd find one that is Taiwanese made and not Chinese made (the latter will be at the lower end of that price spectrum).

[Steven Smith]

I've been quite pleased with my PM-1127 VF in my home shop. The fit/finish is significantly better than what you'd get from something of the Harbor Freight variety.

We're actually having the same discussion on our team regarding a lathe. The other mentors would like to have something in the school shop just to cut spacers to length, and maybe turn an end down now and then. We could get something to handle that for <$1000, but the next $1000-$1500 buys so much more lathe. I know the $5K+ range gives you better material removal rates and the ability to handle even longer/larger stock, but so far my $2.5K home lathe has served me well.

[LisaGinkgo]

Originally Posted by Chak

Thanks for everyone's response!
Our budget is $2000. We don't have a machining mentor, so I think our coach is more comfortable buying new. It looks like our choices are one of the around $1000 benchtop lathes like the ones at Harbor Freight or Little Machine Shop + tooling. Anyone have advice/warnings/experiences with these lathes?

I'm very far from an expert, and I'd recommend taking other people's advise when it comes to comparing the quality of different lathes. I bought a 7x12 mini lathe from Harbor Freight last year though, if you're interested in Harbor Freight lathes. I also bought a quick-change toolpost set from them for it, which has worked out fairly well. As people have mentioned, the lathe has a lot of difficulty handling steel. I used it mostly for aluminum 1/2" hex shafts during Build Season last year, and I've found it works fairly well for basic things (facing, parting, cutting grooves for retaining rings). My main issue with it is that I've had a bit of trouble parting aluminum to length--my parted shafts tend to be about 0.005"-0.01" over or under (delrin spacers are within 0.003" of their desired length). I haven't tried turning threads or anything more complex with it yet, but at least on my team, that's rarely necessary. If you do buy it, I'd recommend buying your cutting tools from someone other than Harbor Freight.
It's definitely nowhere near as good as the Monarch and Hardinge lathes I've used (it's not as powerful, of course, so I generally only take 0.05" cuts if I'm not parting), but it's worked out alright for me.

[protoserge]

Originally Posted by LisaGinkgo

I'm very far from an expert, and I'd recommend taking other people's advise when it comes to comparing the quality of different lathes. I bought a 7x12 mini lathe from Harbor Freight last year though, if you're interested in Harbor Freight lathes. I also bought a quick-change toolpost set from them for it, which has worked out fairly well. As people have mentioned, the lathe has a lot of difficulty handling steel. I used it mostly for aluminum 1/2" hex shafts during Build Season last year, and I've found it works fairly well for basic things (facing, parting, cutting grooves for retaining rings). My main issue with it is that I've had a bit of trouble parting aluminum to length--my parted shafts tend to be about 0.005"-0.01" over or under (delrin spacers are within 0.003" of their desired length). I haven't tried turning threads or anything more complex with it yet, but at least on my team, that's rarely necessary. If you do buy it, I'd recommend buying your cutting tools from someone other than Harbor Freight.
It's definitely nowhere near as good as the Monarch and Hardinge lathes I've used (it's not as powerful, of course, so I generally only take 0.05" cuts if I'm not parting), but it's worked out alright for me.

Have you indicated your parting tool for squareness as you advance it into the part? Have you checked the cross slide squareness with the spindle as it travels across the saddle?