LOOKING FOR A bigger lathe

We can go round and round on this. In the end riversidedan has to make the decision on what will meet his needs. When I get into one of these situations I find writing out a statement of requirements (SOR) really helps the decision process. The SOR will help differentiate between the must have versus the would be nice.

QCTP are great but are not the one size fits all solution to every project. If you are going to be performing the same 3 or 4 operations on a part over and over again swapping out tool holders on a QCTP will soon get to be a drag. Think about making a part that requires 4 different operations. That's 4 tool holder changes. No biggy if you are only making one or two. But what if you are making a 100. That would be 400 tool holder changes. This is where a 4 way would shine. Or maybe a 3 way or a 6 way. I am finding that I do the same 3 operations on most projects. Turning/facing/chamfer, threading and parting off. This holds true for either internal or external. So if I had two 4 ways with one set up for external work and one for internal these two tool holders would satisfy virtually all of my needs. I am currently working on redesigning the post on my QCTP to make a 4 way work on a QCTP.

Although a bigger lathe is not necessarily always better a longer bed is. I would buy the longer bed every time. Bed length can be equated to quill travel on a round column mill drill. We are always fighting trying to cram different tooling into a limited amount of space. The same thing happens on a lathe with a short bed. You run out of room and ideas pretty quickly with the short bed.
 
No one has mentioned tailstock turrets. I have 2 (MT2) if anybody needs one.

1617981134463.png
 
It is true Mickri that we can go in circles with this discussion.
However, I too purchased my first lathe because of my RC hobby. It was ok for RC projects, but quickly ran out of room for anything else. A short lathe would be fine if all the OP is going to do is turn spinners, but if he decides to bore some tubing out for scale landing gear he is now SOL.
We all have different needs and budgets. It is also not lost on me that a lot of RC guys consider a 1/4" drill bit to be huge.
 
There is no substitute for bed length. Longer is always better in my opinion. That's one of the reasons that I bought a 12x36. Not because I needed a 12" lathe. I could get by with a 6" or 7" lathe as long as it had 36" between centers. And I have no idea what size lathe works for model making. I haven't put a model together since I was in grade school. Along with bed length I would think precision is very important in model making. You are making very small precise parts. So a small lathe with the longest bed is what I would be looking for.
 
what kinda long crazy things you guys making that requires a bed that long!!????
 
Last edited:
I have two projects that require a long bed. One is threading and chambering rifle barrels. The other is modifying the axle haft shafts on my MG Midget. I have also made some truing fixtures for rifle actions that are 15" long. The easiest way to keep everything concentric is to turn between centers.
 
Last edited:
riversidedan said:
what kinda long crazy things you guys making that requires a long bed lathe?
Click to expand...
Literally ANYTHING you make that requires any sort of internal dimension is going to make you wish you had more than a 20" bed. On a 10/12" lathe, you can't drill anything since you run out of bed length. Remember that the 10" is the bed length, not the capacity! You need to fit the whole tailstock, chuck, and drill bit in that, in addition to your lathe-chuck AND material.

For me, I started with a 10x36 Logan which was about the perfect starter-size, however I immediately wanted :
1- A quick-change-gearbox. The one I had didn't have one, and I consider this vital. I ended up adapting one, but it was no picnic, and required a lot of precise mill work.

2- The ability to handle a larger swing. Note that thanks to the way chucks work, you automatically lose a couple of inches in swing as soon as you put it in the 3 jaw, unless you can hold it from the 'inside'. Rarely do I buy pipe-stock, so this was rarely an option.

3- A greater headstock spindle passthrough. Being able to have materials stick through the headstock is great, so something with a large through-hole was optimal.

4- The ability to cut more at once. Small lathes have 2 problems; Rigidity and power. When I watched youtube machinists do a cut, they always seemed to be able to do 30/40/50 thou depth of cut. On something like the logan, I was struggling at about 20-30 thou. The machine would either sieze up thanks to rigidity problems, or it would stall thanks to not enough power in the 1hp motor. This makes cutting any meaningful amount diameter a LONG day's work.

I ended up switching to a 16x36" lathe, so you can see no additional length (actually, thanks to the much bigger tailstock, significantly less length!), but the addition of the gearbox, powerfeeds, and ability to take larger cuts was awesome! I went from a 1911 guide-rod taking most of an afternoon, to it being about a 15 minute job.
 
I have a drilling operation that has a 12" stick out, and 11" flute length drill bit for a 10" depth. I used to have to drop the tail stock to mount the MT drill bit, and reassemble.
 
ErichKeane said:
Literally ANYTHING you make that requires any sort of internal dimension is going to make you wish you had more than a 20" bed. On a 10/12" lathe, you can't drill anything since you run out of bed length. Remember that the 10" is the bed length, not the capacity! You need to fit the whole tailstock, chuck, and drill bit in that, in addition to your lathe-chuck AND material.

For me, I started with a 10x36 Logan which was about the perfect starter-size, however I immediately wanted :
1- A quick-change-gearbox. The one I had didn't have one, and I consider this vital. I ended up adapting one, but it was no picnic, and required a lot of precise mill work.

2- The ability to handle a larger swing. Note that thanks to the way chucks work, you automatically lose a couple of inches in swing as soon as you put it in the 3 jaw, unless you can hold it from the 'inside'. Rarely do I buy pipe-stock, so this was rarely an option.

3- A greater headstock spindle passthrough. Being able to have materials stick through the headstock is great, so something with a large through-hole was optimal.

4- The ability to cut more at once. Small lathes have 2 problems; Rigidity and power. When I watched youtube machinists do a cut, they always seemed to be able to do 30/40/50 thou depth of cut. On something like the logan, I was struggling at about 20-30 thou. The machine would either sieze up thanks to rigidity problems, or it would stall thanks to not enough power in the 1hp motor. This makes cutting any meaningful amount diameter a LONG day's work.

I ended up switching to a 16x36" lathe, so you can see no additional length (actually, thanks to the much bigger tailstock, significantly less length!), but the addition of the gearbox, powerfeeds, and ability to take larger cuts was awesome! I went from a 1911 guide-rod taking most of an afternoon, to it being about a 15 minute job.
Click to expand...
All very good points, especially for a beginner. My situation is somewhat similar to the OP in that I started with a UniMat DB-200 waayyy back. It was cheap at the time (1969) and small enough I could keep it on a ship. Having learned the basics on the UniMat, I have usually had access to a "full sized" machine for larger work, so it wasn't an issue.

However, in the early 1990s, I had need of a larger machine and no machinist in his right mind would "loan the use" of such a machine to a (to them) hobbyist. At the time, I only had so much space and funds available. I opted for a Taiwan made 9x19. There was no mainland Chinese machinery available, and the 9x19 was the smallest available. I was, and still am, quite satisfied with such a machine.

However, once falling down the rabbit hole, I kept an eye out, but not actively looking for, a larger machine. I stumbled into a trade with a welding shop in another state for a Craftsman/Atlas 12x36 at a price(trade) I was willing to pay. I acquired it but for numerous circumstances did not commission it for several years.

When the mainland Chinese entered the small machine market, I tried several times to go smaller than the 9x19. Each machine could cut threads that the UniMat couldn't.(without rare attachments) Those machines have been literally given away. They weren't worth the effort to sell. Even the UniMat was sold with most of the attchments I had. I kept a few.

Eventually, my model building drifted into a larger scale. Model trains at 1/8th scale. (1-1/2":1Ft / 7-1/2" guage) There were parts to be made that exceeded the capacity of the Grizzly (9x19) so the Craftsman (12x36) became necessary. Once I did put the larger machine to use, I "retired" the 9x19 to secondary use.

The biggest advantage of the Craftsman was increased rigidity. While on the low end of commercial machines, it was such an improvement over the Grizzly that I kept it as the primary. There is a saying that small parts on a big machine is a lot easier tham big parts on a small machine. But as my skills advanced, I found the bed length to be the greatest advantage. Not having to dis-mount the tailstock for drilling long pieces comes to mind. Though rarely, I do occasionally spool up pieces between centers. Length pays off handsomely at that point.

Though I stay mostly with a smaller (1:87) scale in my model building, I do occasionally do full size work on my tractor and truck. There is no comparison to the smaller machines, beyond being the same basic functions. Many of my parts are too small (<1/8/3mm) to fit the larger machine. I have adapted the UniMat chucks to fit the larger machine. If the job requires exact positioning, tooling for a "normal" size machine is readily available at very reasonable prices. Such tooling is available for the smaller machines, but at horrendous prices.

Overall, I would speculate a 9x19 to be the absolute minimum size machine, even for a model builder. Larger would be better but there are the factors of size and cost. Those are decisions that only the final user can make. But to think that "it's big enough for this project" is a fallacy. Always think ahead to those areas that you wouldn't consider but exist as your skills and needs progress. A small machine works well enough for small jobs, but a full size machine opens a lot of doors that haven't yet been considered.

.
 
You must log in or register to reply here.
Back
Top