Finished boring the hub to take the 1.5" shaft. Hub is cast iron. First time turning with cast iron. Need to re cut the hub's internal 1/4" keyway. Should also cut a new keyway in the shaft so as to not use the one cut with an angle grinder. Need to finish up the power supply for the master mi cut these. Should have the material to make the bush for the internal broach.
Found a 1/2 HP 1725 RPM motor to use. Quite possible its too small but I don't want to fight with a 1.5HP during construction. Maybe make sure I have holes to mount both.
| belt | motor | 1st shaft | 2nd shaft | spindle | ratio |
| V | 2" | 10" | 5:1 | ||
| V | 2.6" | 9.75"* | 3.75:1 | ||
| flat tooth | 2" | 8.5" | 4:1 | ||
| overall | 75:1 |
Should have shafts and bearings from the fitness tables. If I replace the 2.6" pulley with a 2.5 the RPM will not change much. 22 instead of 23. Will look for a 2.5.
* If I replace the 9.75" with a 6" the overall ratio becomes 46:1. 1725/46 is 37.5 RPM. This is starting to seem more reasonable. But may take the 1.5 HP motor to run it so I will try starting with the 9.75". EDIT: Or maybe replace the 2.6 with a larger one because I found the 2.5" I have will not fit the shaft. a 3" results in 3.25:1 or 65:1 overall for 26.5 RPM.
* If I replace the 9.75" with a 6" the overall ratio becomes 46:1. 1725/46 is 37.5 RPM. This is starting to seem more reasonable. But may take the 1.5 HP motor to run it so I will try starting with the 9.75". EDIT: Or maybe replace the 2.6 with a larger one because I found the 2.5" I have will not fit the shaft. a 3" results in 3.25:1 or 65:1 overall for 26.5 RPM.
Later EDIT: if the small pulleys on the motor and shaft 1 are replaced with 2.5" pulleys we
get a reduction of 4 x 3.9 x 4 = 62.5. The 1.5 HP motor is listed as 1740 RPM so 1740/62.4 = ~ 28 RPM. I am thinking there is too much torque to us a 2 in pulleys.
get a reduction of 4 x 3.9 x 4 = 62.5. The 1.5 HP motor is listed as 1740 RPM so 1740/62.4 = ~ 28 RPM. I am thinking there is too much torque to us a 2 in pulleys.
Its 100F. So thinking is better than working. :)
July 9
The heat seems to have gotten to me. Or maybe just too many hours. So I am inside in the cool for a while. Last night I played with the pulleys inside the base. Was thinking about the support structure for the jack shafts. The idea of making slots for adjustment without a milling machine is putting me off.
I have a sheet of decent 1/2" plywood. I think I will double that up and mount the two jack shafts to it. Will be a lot easier to make adjustment slots even if I have to make a slot to run the center belt. Still need to think on this but the tables I am getting most of the pulleys from used plywood for motor mounts. May work here too especially if it laminate 2 sheets. Hopefully it will be good enough to keep. If not it will serve as a prototype.
I have a sheet of decent 1/2" plywood. I think I will double that up and mount the two jack shafts to it. Will be a lot easier to make adjustment slots even if I have to make a slot to run the center belt. Still need to think on this but the tables I am getting most of the pulleys from used plywood for motor mounts. May work here too especially if it laminate 2 sheets. Hopefully it will be good enough to keep. If not it will serve as a prototype.
The wood shop aka garage is cooler than the metal shop so maybe I can work on this in there this afternoon.
Based on the above table
Top will have slots to support the 2nd shaft top bearing and a cutout for the 2" tooth pulley.
In the middle will be slots for the bottom bearing of the 2nd shaft and top bearing of the 1st shaft and a cutout for the center belt.
The bottom will have slots for the 1st shaft bottom bearing and a cutout for the 2" pulley.
To tighten the belts.
Adjust 2nd shaft to tighten top belt.Adjust 1st shaft to tighten middle belt.Adjust motor to tighten bottom belt.
Not 100% sure about the location of the pulley on the bottom of the drum. So maybe leave an extra inch of plywood on top.
July 10
Its too humid for life as we know it. Humidity actually. Installed the window AC unit into the bedroom and closed the door. Swamp cooler was not cutting it.
Found a scrap of plywood that should work. 5/8 or 3/4".
Yaking with Chripy on discord today I realized I could replace they keyway on the hub and main shaft with a shear pin. Thinking I may put copper slugs under the existing set screws to help keep the hub aligned even with the shear pin.
I have also been toying with monitoring the current used by the motor and use a uC to compare that with what I set. Have it trip on over current. That would beat any shear pin because there is nothing mechanical to replace.
Thinking about his the jack shafts are only 1/2" So more suitable for the 3/4 HP motor. These can always be upgraded. Would need to get 4 larger pillow block bearings. Of buy the bearings and cast the blocks.
I have also been toying with monitoring the current used by the motor and use a uC to compare that with what I set. Have it trip on over current. That would beat any shear pin because there is nothing mechanical to replace.
Thinking about his the jack shafts are only 1/2" So more suitable for the 3/4 HP motor. These can always be upgraded. Would need to get 4 larger pillow block bearings. Of buy the bearings and cast the blocks.
July 11
Still thinking about the belts setup but there is something I know I need to do Machine a V groove the cast aluminum pulley. It might have been easy if I had machined a register on the inside of the rim. Maybe a rookie mistake or maybe it would not have been wide enough to serve. Anyway the only way I can see to machine the groove is to mount the pulley to the 14" face plate on the Sidney lathe. The grooves in the plate are 1/2" wide. Rather then use 1/2" bolts I am machining stepped bushings that I will use like T nuts. Turn on the Atlas then file 2 flat spots to fit the face plate slot. This is a stouter way then turning the small end to 1/2". Bolts will go through the bushing/nuts and through plates on face of the pulley. 4 of these should be enough to keep the pulley in place.
Hmm well with the pulley centered only two slots line up. Either have to drill holes or make do. I have fairly heavy plates on the pulley side so maybe it will be good enough.
Hmm well with the pulley centered only two slots line up. Either have to drill holes or make do. I have fairly heavy plates on the pulley side so maybe it will be good enough.
Playing tinker toys with the pulleys axles and bearings to find a solution I like.
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