Jet 1024P - Construction and Build

Friday, February 1, 2013

You might remember from my last post that I’ve acquired an old Jet 1024P metal lathe. The machine is solid but appears to be poorly [if at all] maintained and extremely dirty. In process of removing what looks like three decades worth of chips and grease, I was finally able to closely inspect the lathe, and even run the spindle for a few minutes. I will reserve the final judgement on the condition and quality until the overhaul is done. On the other hand, I have a good idea of the features and the construction. Since I’m upgrading from a 920 lathe, this will be somewhat of a side-by-side comparison of features that I’ve found to be important for my particular needs.

Size and Construction

Jet 1024P Carriage Next to 920's

While doing some basic [and hectic] research before buying this lathe I found some old magazine ads. In those ads Jet calls their 1024P machine “Heavy Duty Bench Lathe”, boasting 1.125” spindle bore, hardened and ground V-ways, helical gears and tapered roller bearings. I can definitely appreciate the larger spindle and the hardened ways, but I was skeptical about the “heavy duty” part. To be honest, going from 9x20 to 10x24 I didn’t expect a huge step, but Jet 1024P appears to be a completely different animal. Out of curiosity I drove by one of the highway scales with the late in the truck, and later without it. According to the scales the machine weighs in the neighborhood of 700 pounds, or at least 2.5 as much as the 920. The increase in weight comes from wider bed, heavier headstock, larger carriage, more substantial cross slide and compound rest, and overall more robust machine that doesn’t use any sheet metal.

Some number for comparison

Jet 1024P Harbor Freight 920
Bed (ways only) 7.25” x 34” 4.5” x 29”
Carriage 12.5” x 11.75” 7.25” x 6.75”
Cross Slide 11” x 4.5” 9.75” x 4”
Compound Slide 7.5” x 3” 4.25” x 2.25”
Jet 1024's Cross Feed Handle

In addition to the sheer weight and size advantage, 1024P has a few more design features that improve it’s rigidity. By using a wider table, Jet’s engineers [or whoever designed this lathe] avoided sharing the ways between the carriage and the tailstock, so the carriage is as wide in the back as it is in the front. The narrower carriage on the smaller lathe is only a part of the problem. By far the biggest issues plaguing Harbor Freight’s (and other’s) 920 lathes are the flimsy compound rest press plate and the cross slide screw bracket. Jet’s screw bracket is shorter and much more robust, so I don’t see it having this problem. When it comes to the cross slide, it avoid the issue by completely omitting the screw bracket, and bolting the compound base directly to the cross slide. Once the two bolts are tightened, cross slide and the compound base turn into an almost monolithic structure.

Noteworthy Fetures

Probably the most welcome feature found on 1024P is the powered crossfeed. The power feed lever has three indexable position: neutral, power feed and cross feed. Surprisingly, unlike most modern small lathes, engaging the power feed doesn’t lock out the half nut engagement and vice versa. I have already taken the apron apart and it appears that there are no provision for such lockout. Power feeds are mutually exclusive, though. In fact, cross feed handle is blocked when the longitudinal power feed is engaged.

When it comes to the 920 lathe, probably the most common upgrade after the cross slide and compound clamp is a reversing lever. As you probably guessed, 1024P comes with a lead/feed reversing mechanism out of the box. The lathe has a three-position lever (forward-neutral-reverse) that enables the machinist to cut left-hand threads or feed from the headstock.

As far as the threading is concerned, Jet’s 1024 lathe can cut a good range of metric and inch tread sizes. The manual states that using two change leavers, one can select one of the 40 inch treads ranging from 4 to 112 TPI. With installed metric gears, the lathe offers metric threads from 0.35 to 4.5 per mm in 24 steps. In comparison, 9x20 can cut 27 inch and 11 metric threads, 8-56 TPI and 0.5-3.0 mm respectively. Furthermore, cutting those threads should be a lot less exciting, since the lathe offers 70 RPM in the lowest “gear”.

My favorite convenience feature is the tailstock cam lock. I was planning to do this mod on my 920 lathe, so having one out of the box saves me some trouble.

Finally, the thing that put a wide grin on my face was the spindle and belt drive design. For me personally the 5mm drive belt has been the biggest pet peeve with my Harbor Freight lathe. After breaking $100 worth of those belts I pretty much gave up parting on the lathe. Even that didn’t save me from forking out $25 every few months. In contrast, Jet uses standard V-belts with a beefy countershaft and proper backgears. Looking at the two lathes side-by-side I can’t help but wonder if 920 “designers” had LSD in their water supply.

Conclusion

You might’ve noticed that I’m pretty excited about the lathe. Frankly, for the vast majority of my projects my 920 lathe was almost adequate. I wouldn’t take too much effort to turn 920 into a very capable machine. On the other hand, having all those upgrades out of the box, in conjunction with more mass and rigidity should give me more flexibility.

To be fair, though, we should keep in mind that those two lathes aren’t in the same league. Jet sold 1024P for $1700 in late 70’s. Adjusted for inflation, this is over $7200 in todays money, or almost 10 times what Harbor Freight 9x20 can be had for with their perpetual “limited time” 20% off coupon.

2 comments :

  1. Get yourself a real lathe. Both are toys. HF 920 is a complete POS, Jet is a better POS. Both are only good for making fish habitat.

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  2. What an arrogant ass. This lathe will outperform many "modern" small shop (Harbor Freight) lathes. Built like a tank with many fine features now found in only larger industrial machines. Yes, to a professional machinist this might be a "toy" in comparison but for for a home hobbyist this is a beautiful machine and will last generations.

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