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Topic: Half Stop That Works |
Dennis Detweiler
From:
Solon, Iowa, US
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Posted 17 Jan 2020 10:22 am |
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This is the half stop that I wangled and installed on my msa. The tuner is a Peavey amp knob. I drilled the center and pressed a tuning nut into it. The rod is notched to fall into a roller. The 1/2 tone is tuned when the rod notch is setting in the roller.
To tune the whole tone, continue to push the knee lever which brings the notch out of the roller and tune the whole tone from the end plate. The tuners are independent of each other, so one doesn't effect the other. The spring pulls down on the rod and drops the rod notch into the roller. You can adjust the feel by installing a lighter or heavier spring. I used a 1/4 inch roller and a 1/4 inch rat tail file to make the notch fit nicely onto the roller.
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Bill C. Buntin
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Posted 17 Jan 2020 10:40 am
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Dennis
That’s a great idea. I installed one similar on a d10 dekley several years back. I like the knob. Mine was essentially the same only with a knurled nut. I think mr Franklin sr used a similar setup for half stops. I’ve been wanting to make the 1/2 stop on my vertical a bit more positive than it is presently. I can think of two more places on mine where I could use this. Example, The 2nd string lower is conventional where the 1/2 stop is felt when string nine engaged, but it’s kind of wimpy. This just might do the trick. Thanks for sharing.
Bill |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 17 Jan 2020 11:31 am
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This eliminates most of the traditional "feel" to get a definite stop. The traditional spring system always had a spongy feel which created a little guess work to accuracy. Nothing spongy here. Plus, once pushing past the notch (half stop) the continued travel feel to the whole tone is the same as the beginning travel feel to the half tone. The traditional spring system created a stronger resistance as you continued to the whole tone.
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 1 Feb 2020 10:01 am
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I have a 30 second video of the half stop, but it won't load onto the post. It evidently is the wrong format. I can send it to my own email, but not to private messages?
It says, datatype avi not supported.
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Richard Sinkler
From:
aka: Rusty Strings -- Missoula, Montana
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Posted 1 Feb 2020 12:15 pm
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If you have a half stop on a guitar that uses another string activation for the feel stop, like lowering string 9 to get the feel stop at D on string 2, you can cut 1 loop off the return string on string 9 to create more tension (or adjust the spring tighter if you have adjustable return springs). But, I think a physical, tunable feel stop is best. Good job on this.
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Carter D10 8p/8k, Dekley S10 3p/4k C6 setup,Regal RD40 Dobro, NV400, NV112 . Playing for 54 years and still counting. |
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Richard Sinkler
From:
aka: Rusty Strings -- Missoula, Montana
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Posted 1 Feb 2020 12:17 pm
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| Dennis Detweiler wrote: |
I have a 30 second video of the half stop, but it won't load onto the post. It evidently is the wrong format. I can send it to my own email, but not to private messages?
It says, datatype avi not supported. |
You have to upload the video to a video hosting site, like YouTube, and provide a link to it in your post. The forum doesn't support uploading audio or video directly.
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Carter D10 8p/8k, Dekley S10 3p/4k C6 setup,Regal RD40 Dobro, NV400, NV112 . Playing for 54 years and still counting. |
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Dick Sexton
From:
Greenville, Ohio
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Posted 1 Feb 2020 2:13 pm Diagram
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I was having a hard time understanding just how it worked. Thought two overlaying rods were welded to one another. Diagrammed it out. Easier for me.
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 1 Feb 2020 8:00 pm
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Dick, your diagram is correct. You can also use a flat washer in place of the floating collar where the cross shaft moves against the sleeve.
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Tom Campbell
From:
Houston, Texas, USA
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Posted 2 Feb 2020 11:41 am
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Dick,
Would you happen to have copy of your diagram that doesn't have the dark back ground...I would like to print off a copy if that is OK. |
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Dick Sexton
From:
Greenville, Ohio
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Posted 2 Feb 2020 1:44 pm Diagram
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| Tom, email me. |
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Tom Campbell
From:
Houston, Texas, USA
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Posted 2 Feb 2020 4:22 pm
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Hi Dick
Email sent via the Forum. |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 5 Feb 2020 8:16 am
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Since the half stop rod works independently from the changer pull rod and the pulling lever, the slight angle of the spring from it's anchor to the notched pull rod causes the half stop rod to slide back and into the notch when the knee lever is released. Since the half stop rod is riding on a roller, the half stop rod floats freely with little friction. It doesn't take much spring angle to make it roll backwards into the notched half stop rod. I used a roller that I salvaged from a Magnavox radio tuner. I have some spare rollers if needed. They already have a 1/8 inch axle hole in them. A chunk of 1/8 inch pull rod works for the axle. The detent mount is from an extra MSA vertical knee lever mount, but it wouldn't be difficult to make a detent mount from a piece of aluminum stock.
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 5 Feb 2020 8:30 am
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A better picture:
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Tom Campbell
From:
Houston, Texas, USA
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Posted 5 Feb 2020 9:07 am
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| Is there enough return pull from the changer to prevent the notched rod from hanging up on the half-stop roller, if the bell crank in engaged in a full throw to the lever's stop? |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 5 Feb 2020 12:44 pm
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The half stop rod is independent from the pull rod and changer when the knee lever is released from the
full tone. The half stop rod is not linked to the pull rod and changer with a locking screw. If you were to move the half stop rod by hand the pull rod and changer would not move. The half stop rod moves forward only when you engage the knee lever. When you release the knee lever, the half stop rod will not move backwards when the knee lever moves backwards. The only device that moves the half stop rod back to the half stop (notch position) is the coil spring that pulls down and back on the half stop rod. I put 3 grooves on top of the half stop rod to hang the downward pulling spring onto. It is pulling at enough of a slight angle to pull the half stop rod back until it drops onto the roller notch. The roller basically doesn't create enough drag on the rod to be noticeable when engaging to the full tone. I'm guessing that even if the roller didn't roll it would probably create a miniscule amount of drag. When you engage to the half stop feel, you're actually feeling the half stop notch already setting in the roller. Then you push it out of the notch to the kneelever's normal factory built full tone stop. Release the knee lever from the full tone stop and the knee lever, factory pull rod and changer returns to rest postion. The half stop rod is on it's own to return to the half stop notch position by way of the downward and slight backward angle of the spring. Hope I'm making sense? 
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Tom Campbell
From:
Houston, Texas, USA
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Posted 5 Feb 2020 2:32 pm
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Thanks Dennis...I understand the concept.
The distances the half-stop rod must travel is fairly small...not multiple numbers-of-inches. So, the spring, at a slight angel, should be enough to return it to it's starting position.
Nice design! |
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Dennis Detweiler
From:
Solon, Iowa, US
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Posted 5 Feb 2020 6:46 pm
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The distance from the half stop to full tone is so short that the notch barely gets up and out of the roller. So, the little spring doesn't move much.
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1976 Birdseye U-12 MSA with Telonics 427 pickup, 1975 Birdseye U-12 MSA with Telonics X-12 pickup, Boss 59 Fender pedal for preamp, NDR-5 Atlantic Delay & Reverb, two Quilter 201 amps, 2- 12" Eminence EPS-12C speakers, ShoBud Pedal, 1949 Epiphone D-8. Revelation preamp into a Crown XLS 1002 power amp. |
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Ian Rae
From:
Redditch, England
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Posted 22 Oct 2021 8:15 am
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Just what I've been trying to design for ages.
Dennis, you're a genius
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Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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