Attn: All Owners of Delta 1440VS Lathe (and possibly Jet 1236)

[Dick Strauss]

Well,
I managed to figure out a way to get slow enough speeds on my Delta 1440 (46-715) to turn off-balance 14" chunks of wood. I made a few mods to the reeves drive system after reviewing the parts diagram. Now I have a lathe that has a slowest speed of roughly 150rpms (a guesstimate) instead of 450-500rpms. Boy what a difference for turning and sanding!!! Better yet, the price was right...it didn't cost me a dime!!!

And to think I was considering running 220V/3ph+inverter to achieve a slightly better solution.

PM me if you want more details...it is quite simple to do but hard to communicate. I don't know if this mod will work for other reeves drive systems (like the Jet 1236s).


Best of luck,
Dick

[Bill Boehme]

There are numerous ways of doing this. On a Reeves system, the drive ratio is a function of center-to-center distance, belt length, and pulley sizes. It is also affected slightly by spring tension. This means that on the Delta lathe, the speed can be slowed down by putting a weaker spring on the motor shaft although this change in speed is minimal and results in belt slipping. Installing a spacer underneath the motor mounting bolts can be used to decrease the spindle speed. Also, using a shorter belt can be used to decrease the spindle speed. However, I am suspect of the 100 RPM number that you gave because that would require a pulley diameter on the motor shaft that is smaller than the motor shaft diameter itself. What method did you use to measure the speed? The best speed reduction possible on this lathe would be about 375 - 400 RPM.

You need to be extra careful about opening up the spacing too much on the motor pulley halves or closing up the spacing too much on the spindle pulley halves. Either situation can lead to problems not to mention that it will limit the overall speed range.

Bill

[Bill Boehme]

There is one other thing that I forgot to mention in my previous post that will extend the speed range slightly. The speed control lever locks into detents to maintain each speed. If you look carefully at the plastic detent ring, you will notice that there are places at the high and low ends of the ring to add one more detent notch. The outline is even conveniently marked for you. A little bit of scrollsaw work and some sanding is all that it takes to do this. You may also be able to extend the range of the rack and pinion gear by one tooth at the low end to nudge the low speed down a bit more.

If you go too far though, the belt will get trapped beneath the spokes on the motor pulley and if that happens, you will need to remove the belt shroud and pry the pulley open to dislodge the trapped belt. Then you will need to make sure that everything is rigged so that you stay away from that coffin corner of the envelope unless you like working on your lathe.

Bill