- Joined
- Jan 8, 2020
- Messages
- 177
Edit:
I just realized that this thread started in 2014 and was just recently revived. For anyone else reading, be aware that the endorsements of "JT" support may no longer be valid. The company has been renamed a couple of times and is now known as "Chicago Lathe". They do seem to have some manuals and such under the "Technical Files" tab.
End-of-Edit
I have a 1720 purchased new in 1998 or so. You have to go into these machines with your eyes open. I bought it because it had the motor mounts for a LinuxCNC conversion, which I finally did in 2007. I like the CNC capabilities, but as a manual machine it definitely has limitations.
Of the 3 functions in "3-in-1"":
Lathe: not bad. The large swing is nice for some things. Dovetail instead of flat-and-vee ways means that the saddle will skew sideways a little when you change feed direction from right-to-left vs left-to-right. Especially when using a boring bar that will change your size. Just have to keep it in mind and make allowances. No half-nuts, so manual threading is a PITA. I think they've addressed that over the years, I solved the problem by going CNC with a spindle encoder. The tailstock travel on mine is very short (about 1.5"). Again, I think they've improved that over the years. The lathe drivetrain leaves a bit to be desired, the vee-belt on mine slips whenever I try anything approaching a heavy cut. I could probably improve that by trying to get the belts a bit tighter, but the basic design makes speed changes a multi-minute job requiring wrenches. I find it very frustrating. One of these days I intend to install an oversized three-phase motor, VFD, and some sort of toothed-belt drive train with a high range and a low range.
Mill: very limited. The quill travel is about 3.5 inches and there is no knee. So you are forever figuring out ways to block your work up from the table. Invest in a set of screw-machine length drill bits; it is just about impossible to mill (with a short holder for rigidity) and drill (with a chuck and a longer drill bit) on the same workpiece without re-setting the part. You'll also want to buy or make some risers for your vise, and have some 1-2-3 and 2-4-6 blocks handy, as well as lots of all-thread, tee-nuts, etc, for building setups. Rigidity is very poor compared to a bridgeport or other real machine due to the long and fairly narrow millhead casting, and the fact that your parts are often perched on top of some kind of risers. Again, CNC makes a difference, because you can take many light cuts without getting too frustrated, and CNC in general lets you do things that would be much more complicated otherwise. Over the years the company has tried to address the problem with a variety of design changes: raising and lowering the head, braces at the tailstock end, the "bridgemill" version, etc. I have no experience with those versions so I can't comment on whether they have improved things.
Drill Press: forget about it. The short quill travel and no knee will drive you insane. On a real drill press where the table can be easily raised and lowered you can switch from a short center drill, to a long drill for the hole, then to a short countersink, etc. On this machine that will drive you nuts. I have a nice floor-standing Clausing drill press that I got less than a year after I bought the Shoptask and sits right next to it. For most projects, I use a short center drill or spotting drill in an endmill holder (to roughly match the length of end mills). I spot the holes at the proper location on the Shoptask (using CNC), then I pull the part off the shoptask and take it to the drill press to actually drill/countersink/counterbore/tap the holes. This is another place where CNC is a win - I can be drilling one part on the drill press (and then deburr it with files, etc) while the CNC is milling and spotting the next part. Of course that only helps when making several copies of some part.
I just realized that this thread started in 2014 and was just recently revived. For anyone else reading, be aware that the endorsements of "JT" support may no longer be valid. The company has been renamed a couple of times and is now known as "Chicago Lathe". They do seem to have some manuals and such under the "Technical Files" tab.
End-of-Edit
I have a 1720 purchased new in 1998 or so. You have to go into these machines with your eyes open. I bought it because it had the motor mounts for a LinuxCNC conversion, which I finally did in 2007. I like the CNC capabilities, but as a manual machine it definitely has limitations.
Of the 3 functions in "3-in-1"":
Lathe: not bad. The large swing is nice for some things. Dovetail instead of flat-and-vee ways means that the saddle will skew sideways a little when you change feed direction from right-to-left vs left-to-right. Especially when using a boring bar that will change your size. Just have to keep it in mind and make allowances. No half-nuts, so manual threading is a PITA. I think they've addressed that over the years, I solved the problem by going CNC with a spindle encoder. The tailstock travel on mine is very short (about 1.5"). Again, I think they've improved that over the years. The lathe drivetrain leaves a bit to be desired, the vee-belt on mine slips whenever I try anything approaching a heavy cut. I could probably improve that by trying to get the belts a bit tighter, but the basic design makes speed changes a multi-minute job requiring wrenches. I find it very frustrating. One of these days I intend to install an oversized three-phase motor, VFD, and some sort of toothed-belt drive train with a high range and a low range.
Mill: very limited. The quill travel is about 3.5 inches and there is no knee. So you are forever figuring out ways to block your work up from the table. Invest in a set of screw-machine length drill bits; it is just about impossible to mill (with a short holder for rigidity) and drill (with a chuck and a longer drill bit) on the same workpiece without re-setting the part. You'll also want to buy or make some risers for your vise, and have some 1-2-3 and 2-4-6 blocks handy, as well as lots of all-thread, tee-nuts, etc, for building setups. Rigidity is very poor compared to a bridgeport or other real machine due to the long and fairly narrow millhead casting, and the fact that your parts are often perched on top of some kind of risers. Again, CNC makes a difference, because you can take many light cuts without getting too frustrated, and CNC in general lets you do things that would be much more complicated otherwise. Over the years the company has tried to address the problem with a variety of design changes: raising and lowering the head, braces at the tailstock end, the "bridgemill" version, etc. I have no experience with those versions so I can't comment on whether they have improved things.
Drill Press: forget about it. The short quill travel and no knee will drive you insane. On a real drill press where the table can be easily raised and lowered you can switch from a short center drill, to a long drill for the hole, then to a short countersink, etc. On this machine that will drive you nuts. I have a nice floor-standing Clausing drill press that I got less than a year after I bought the Shoptask and sits right next to it. For most projects, I use a short center drill or spotting drill in an endmill holder (to roughly match the length of end mills). I spot the holes at the proper location on the Shoptask (using CNC), then I pull the part off the shoptask and take it to the drill press to actually drill/countersink/counterbore/tap the holes. This is another place where CNC is a win - I can be drilling one part on the drill press (and then deburr it with files, etc) while the CNC is milling and spotting the next part. Of course that only helps when making several copies of some part.
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