Wow, all this information to digest. Thank you all. It is a Jet 13-R, with one belt and two four step pulley's. Really a heavy cast foot and table. Bought it from the widow across the street after her husband died of brain cancer for $100. Myself being on fixed income... it would be a hardship to sink hundreds of dollars into it now...BUT looking at the intermediate shaft has its rewards. I may lose the cover, as the plastic housing is rather long and skinny, or perhaps severely modified. Thank you for all your help.
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Gearing Down A Jet Drill
- Thread starter toolroom
- Start date
- Joined
- Dec 19, 2014
- Messages
- 167
Don't know for sure. I have seen where people complain about loosing torque and others say they are great. I suspect a lot has to do with the quality of the vfd. Good units have torque boost on them. I have a couple vfd units but mainly use them to generate 3 phase at 60 hz. My mill has a veri-drive on it. The other is on a carbide grinder.
From a cost stand point dc is cheaper. I just bought. speed control for $90. It's a Baldor/ABB unit and has regenerative breaking on it. Not sure about reverse. Treadmill motors are around 1hp. If this works out well, I'm planning on converting my 9" SB lathe to dc.
- Joined
- Jan 2, 2014
- Messages
- 9,241
Hi Daryl,
It looks like just a tube fixed to the head frame. The tube needs to be long enough to resist the bottom pin twisting out of a vertical orientation. The bottom pin on one end of the crank simple drops into the tube with no bearings on that end. The bottom pin is only a 4-5 inches long. No bearing required, as it is really only used to adjust the intermediate shaft and pulley along an arc. The tension of the two belts in opposing directions is all the holds it.
You want to be sure that the pulley steps align well. Adding simple spacer washers to the bottom pin could lift the crank arm up.
-brino
Absolutely correct.
It looks like just a tube fixed to the head frame. The tube needs to be long enough to resist the bottom pin twisting out of a vertical orientation. The bottom pin on one end of the crank simple drops into the tube with no bearings on that end. The bottom pin is only a 4-5 inches long. No bearing required, as it is really only used to adjust the intermediate shaft and pulley along an arc. The tension of the two belts in opposing directions is all the holds it.
You want to be sure that the pulley steps align well. Adding simple spacer washers to the bottom pin could lift the crank arm up.
Your welcome. I was trying to save a thousand words!
-brino
- Joined
- Jan 2, 2014
- Messages
- 9,241
one related thread:
http://www.hobby-machinist.com/threads/hf-drill-press-how-to-improve-horsepower.21781/
but it's still not the one I was thinking of......maybe it was in a magazine, or youtube video....hmmmm...
http://www.hobby-machinist.com/threads/hf-drill-press-how-to-improve-horsepower.21781/
but it's still not the one I was thinking of......maybe it was in a magazine, or youtube video....hmmmm...
- Joined
- Jan 2, 2014
- Messages
- 9,241
Yes, that's it! Thanks Frank.
I don't know how I missed it in my search, I used many of the same terms....oh well.
Here's the direct link:
http://www.hobby-machinist.com/threads/slowing-down-my-drill-press.33007/
I specifically remembered the pictures in post #12:
http://www.hobby-machinist.com/threads/slowing-down-my-drill-press.33007/#post-280592
because that machine already had a mounting hole for the intermediate shaft crank arm.
Thanks again Frank!
-brino
Thanks Brino,
I took the pulley's off the Jet and cleaned everything up the post is hollow with a cast cap, which I made a plug in which to install the center shaft when it arrives from Grizzly. Got all the parts ordered so I hope it all works out. My concern is that I have a four step pulley and I think the Grizzly is a 5 step pulley, we'll wait and see.
toolroom
I took the pulley's off the Jet and cleaned everything up the post is hollow with a cast cap, which I made a plug in which to install the center shaft when it arrives from Grizzly. Got all the parts ordered so I hope it all works out. My concern is that I have a four step pulley and I think the Grizzly is a 5 step pulley, we'll wait and see.
toolroom
brino,
The Grizzly parts arrived late evening, I'm scratching my head on this one. The schematic shows two bearings, however the pulley depth would only accept one, with lateral play. I will try, and see if it will work, but I'm skeptical at higher speeds.
toolroom
The Grizzly parts arrived late evening, I'm scratching my head on this one. The schematic shows two bearings, however the pulley depth would only accept one, with lateral play. I will try, and see if it will work, but I'm skeptical at higher speeds.
toolroom
- Joined
- Mar 16, 2016
- Messages
- 14
I swapped the 1/2 hp motor for a 3/4 hp in my drill press. I did this mod so I would not have to changes belt positions too often. I can adjust from 66 RPM's to 1677 RPM's with just the turn of a pot, that's with the belt position set for 750 RPM. It does have a torque boost setting that works great. If I intend to use at low RPM for many holes, then I will change the belt so the motor can cool itself. I should have stuck with 120v rather than going to 220v. The conversion was about 250$. It was more than I paid for the drill press. It was worth it, having very low rpm range also.