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pmangels17 24-11-2015 17:55

Re: buying a lathe?
 
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 25-11-2015 00:15

Re: buying a lathe?
 
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 25-11-2015 02:57

Re: buying a lathe?
 
Quote:

Originally Posted by Chak (Post 1507747)
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 25-11-2015 07:18

Re: buying a lathe?
 
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 25-11-2015 15:32

Re: buying a lathe?
 
Quote:

Originally Posted by protoserge (Post 1507760)
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 25-11-2015 15:34

Re: buying a lathe?
 
Quote:

Originally Posted by Chak (Post 1507824)
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 25-11-2015 15:51

Re: buying a lathe?
 
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.

sanddrag 25-11-2015 16:58

Re: buying a lathe?
 
If you're on a budget, I've recommended it before to teams in your shoes and I'll recommend it again. You might want to take look at the Harbor Freight 44859.
http://www.harborfreight.com/8-inch-...the-44859.html

It's easily twice the machine of a 7" lathe and can probably be bought for $800 using a 20% off coupon.

Mine has just about 10 years in it now and the only thing I've replaced is two bolts. It sits nicely on top of the HF 13 drawer 44" tool chest too.

Cory 25-11-2015 17:07

Re: buying a lathe?
 
Quote:

Originally Posted by AdamHeard (Post 1507825)
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).

R.C. 25-11-2015 17:19

Re: buying a lathe?
 
Quote:

Originally Posted by protoserge (Post 1507829)
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.

Steven Smith 25-11-2015 17:21

Re: buying a lathe?
 
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.

protoserge 25-11-2015 21:40

Re: buying a lathe?
 
Quote:

Originally Posted by R.C. (Post 1507842)
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. :)

LisaGinkgo 25-11-2015 22:39

Re: buying a lathe?
 
Quote:

Originally Posted by Chak (Post 1507747)
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 26-11-2015 07:53

Re: buying a lathe?
 
Quote:

Originally Posted by LisaGinkgo (Post 1507885)
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?

WoodWerkr 26-11-2015 13:50

Re: buying a lathe?
 
I have some experience with two of the bench-top lathes mentioned. I was not a metal lathe user before this so am coming from the perspective of still coming up the learning curve on lathe work.

Team 2471 has used the Grizzly 602 for 3 years. Works well for the stated objective of drive shaft ring grooves and like level work. Was and continues to be a great addition to our shop due to low cost and bench top footprint.

As team learned to use the lathe and took on more complex project projects (think swerve drive spindles and two speed shift shafts) the 602 was not a sufficiently stable tool.

I have a PM 1127 at home and with DRO added it is capable enough for these next level projects. Selected the PM 1127 as the largest and best value lathe that could be manhandled into my basement shop. Took some care in setting and tuning it and am very happy with the choice after a year of use.

I recommend the PM 1127 if you can swing the extra $1000 . Still a bench-top machine but will take your team a lot further. Otherwise the Grizzly 602 will certainly achieve your stated goals.

One warning about each system:
The Grizzly 602 tail-stock has been an ongoing item for repairs. It jams easily and has limited travel. There does not seem to be a cost effective path to get replacement or replacement parts. Be sure that all the users know how to use and take care of it.

The PM 1127 was on not in stock when I ordered. It took a long time (5 months) to arrive.


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