- Joined
- Aug 7, 2013
- Messages
- 22
Having owned a used CX701 for a little, wasn't sure if I had the complete set of gears that was supposed to have come with the lathe. Also, was very disappointed to see that if you have the 8tpi leadscrew machine, you only get 13 change gears (vs 14 change gears sold with competitors 11x27 lathe), no change gear setup for 13tpi threading and the metric threading chart only shows 8 possible mm threads..
Well, here's a few discoveries that I made that I wanted to share:
1) CX701 comes with 13 gears (5 installed/8 spares); Here's what the list of change gears you're supposed to get with the CX701 (in teeth): 20, 25, 30, 40, 45, 50, 55, 60, 63, 70, 75, 80, 80
2) there is an OPTIONAL 65-tooth gear that you can order from Busy Bee ($30 - part # PCX70165T) that will allow you to cut true 13tpi threads. You CAN cut a 12.99TPI thread with the OEM change gears but Busy Bee doesn't publish what that gearing combination is and would rather sell you an extra gear. Consider that some of their other threading options aren't 100% accurate also, some people may feel its not worth buying the extra gear. One thing I will say is that the 65T gear does increase accuracy on some other gearing changes so if you're wanting to increase precision/have a few more threading options, it's something that is available.
3) this lathe apparently is manufactured in 2 configurations: SAE model with 8tpi leadscrew w/13 OR 14 change gears and a metric leadscrew version (unsure of the rod pitch) w/14 change gears. Have only seen the BusyBee-branded lathe in the SAE version/13 gear and the change gear plate on the machine refers solely to that. However, in the manual, it shows BOTH Metric and SAE leadscrew model charts. One thing that becomes quickly apparent is that, if you bought the SAE/CX machine, it shows only half of the metric threading combinations vs Metric leadscrew model and you say to yourself 'geez...wished they would have provided the metric leadscrew model instead'. Fear not...the SAE model chart is simply missing what the gearing combinations are...you CAN make most of the Metric thread pitches you see on the metric-rodded machine (except the ones that require the 65T gear). I assembled some change gear programming software and configured it to suit the CX701 and it claims I can make 16 of the most-common metric threads with OEM/13 gears and up to 24 metric threads (some also using the 65T) with <1% error. Unsure why Busy Bee or their supplier makes the SAE model look so limited on the metric threading side...will have to manually fit some of these gearing combinations to double-check but the math says its possible to make many more Metric threads than what the chart shows.
Speaking of the change gear software, it is adjustable e.g. can be used for other lathes with different number of change gears, different pitched threaded rod, etc and works better than any of the software/change gear web pages I could currently find on the Internet. Most change gear web pages only work for smaller lathes and dont have the same gear layout possibilities as the CX701/PM1127 . I'm willing to help people figure out gearing combinations but am not ready to share the program at this time (spending my time unemployed, handing out software, isn't something I can live on).
If anyone is curious if there is a change gear combo for an unlisted pitch on their machine (TPI or mm), shoot me a message with: 1) list of change gears you have 2) number of gear teeth on the spindle (e.g. CX701 has 40) 3) the pitch of the leadscrew on their machine and I'll see if I can calculate a useful change gear combo; note: the combination may not produce 100% accurate thread but I'll tell you what the actual calculated thread is and you can decide for yourself if it's accurate enough....most of them I can get down to the sub-1% error range as long as you have a complete set of gears.
Well, here's a few discoveries that I made that I wanted to share:
1) CX701 comes with 13 gears (5 installed/8 spares); Here's what the list of change gears you're supposed to get with the CX701 (in teeth): 20, 25, 30, 40, 45, 50, 55, 60, 63, 70, 75, 80, 80
2) there is an OPTIONAL 65-tooth gear that you can order from Busy Bee ($30 - part # PCX70165T) that will allow you to cut true 13tpi threads. You CAN cut a 12.99TPI thread with the OEM change gears but Busy Bee doesn't publish what that gearing combination is and would rather sell you an extra gear. Consider that some of their other threading options aren't 100% accurate also, some people may feel its not worth buying the extra gear. One thing I will say is that the 65T gear does increase accuracy on some other gearing changes so if you're wanting to increase precision/have a few more threading options, it's something that is available.
3) this lathe apparently is manufactured in 2 configurations: SAE model with 8tpi leadscrew w/13 OR 14 change gears and a metric leadscrew version (unsure of the rod pitch) w/14 change gears. Have only seen the BusyBee-branded lathe in the SAE version/13 gear and the change gear plate on the machine refers solely to that. However, in the manual, it shows BOTH Metric and SAE leadscrew model charts. One thing that becomes quickly apparent is that, if you bought the SAE/CX machine, it shows only half of the metric threading combinations vs Metric leadscrew model and you say to yourself 'geez...wished they would have provided the metric leadscrew model instead'. Fear not...the SAE model chart is simply missing what the gearing combinations are...you CAN make most of the Metric thread pitches you see on the metric-rodded machine (except the ones that require the 65T gear). I assembled some change gear programming software and configured it to suit the CX701 and it claims I can make 16 of the most-common metric threads with OEM/13 gears and up to 24 metric threads (some also using the 65T) with <1% error. Unsure why Busy Bee or their supplier makes the SAE model look so limited on the metric threading side...will have to manually fit some of these gearing combinations to double-check but the math says its possible to make many more Metric threads than what the chart shows.
Speaking of the change gear software, it is adjustable e.g. can be used for other lathes with different number of change gears, different pitched threaded rod, etc and works better than any of the software/change gear web pages I could currently find on the Internet. Most change gear web pages only work for smaller lathes and dont have the same gear layout possibilities as the CX701/PM1127 . I'm willing to help people figure out gearing combinations but am not ready to share the program at this time (spending my time unemployed, handing out software, isn't something I can live on).
If anyone is curious if there is a change gear combo for an unlisted pitch on their machine (TPI or mm), shoot me a message with: 1) list of change gears you have 2) number of gear teeth on the spindle (e.g. CX701 has 40) 3) the pitch of the leadscrew on their machine and I'll see if I can calculate a useful change gear combo; note: the combination may not produce 100% accurate thread but I'll tell you what the actual calculated thread is and you can decide for yourself if it's accurate enough....most of them I can get down to the sub-1% error range as long as you have a complete set of gears.
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