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PT-18 MRP F 4th Valve Slides
Posted: Wed Apr 01, 2015 7:17 pm
by apsapienza
The 4th valve slides on my MRP F are too long (I think?) Neither end can be pushed in all the way without pushing the other end out by about 3/4 of an inch.
My question is, is this the way it was supposed to be designed, or is it a mis-cut on the tube's lengths?
Yes - I have tried reversing the tubes, they don't fit at all this way.
No - This is not an April Fool's Day related question.
Thanks

Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 7:41 am
by michael_glenn
Is it the slide pushing the other slide, or is it pressure? On my previous CC, my third slides would move each other due to pressure. Just had to hold the valve down.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 10:42 am
by apsapienza
No, the slides are definitely pushing each other. Double-checked just now.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 10:48 am
by TubaZac2012
I owned one of these for nearly 3 years, and I couldn't figure out why. I just figured it was a design flaw.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 10:52 am
by bort
Take the slide out, and hold it in front of the receiving tubing. Then you can see very easily if the ends of the slide tubing go too far down.
I know that some tubas are made with very long pulls for the 4th valve slides, but something sounds a bit unusual here.
Dumb question that might not even make sense -- are you sure you have the 4th valve slide in the 4th valve tubing? Not like you have the 3rd and 4th slides reversed or something?
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 11:11 am
by Tom
It's not supposed to be like that.
Just look at this photo. All of the slides can be pushed all the way in, at least as far as I can tell...
Ref:
http://www.b-and-s.com/download-brasswi ... -MRP-F.pdf
I agree with those that think you accidentally have some of the slides switched around incorrectly.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 11:18 am
by apsapienza
Bort, Bloke, Tom,
I tried every other side, including 5th, and they're all too wide or too narrow, none of them fit the 4th slide's tube width.
Switching the 4th top slide with the 4th bottom slide, the top slide sticks out about three inches when on the bottom.
I think the tube's too long.
TubaZac, I was wondering if you had the same problem on yours.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 11:19 am
by bort
Come to think of it, I think an old PT-3 I used to use had interchangeable 3rd and 4th slides... with the difference being the length of the slide.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 11:22 am
by apsapienza
bort wrote:Come to think of it, I think an old PT-3 I used to use had interchangeable 3rd and 4th slides... with the difference being the length of the slide.
My top 3rd valve slide is too narrow to fit, my bottom 3rd valve slide is too wide to fit :/
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 12:00 pm
by TubaZac2012
apsapienza wrote:Bort, Bloke, Tom,
I tried every other side, including 5th, and they're all too wide or too narrow, none of them fit the 4th slide's tube width.
Switching the 4th top slide with the 4th bottom slide, the top slide sticks out about three inches when on the bottom.
I think the tube's too long.
TubaZac, I was wondering if you had the same problem on yours.
That's not why I sold the horn at all. Great playing horn, just didn't use it, probably will regret it down the road, but I just didn't need the horn. It plays great, regardless, FYI Mr. P's is like this as well.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 1:47 pm
by jsmn4vu
apsapienza wrote:The 4th valve slides on my MRP F are too long (I think?) Neither end can be pushed in all the way without pushing the other end out by about 3/4 of an inch.
Modification by a previous owner, perchance?
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 2:21 pm
by apsapienza
jsmn4vu wrote:apsapienza wrote:The 4th valve slides on my MRP F are too long (I think?) Neither end can be pushed in all the way without pushing the other end out by about 3/4 of an inch.
Modification by a previous owner, perchance?
Nay, I bought the horn new.
I'll check again, Bloke, but all the slides only fit one spot on the horn. Every other slide is either too narrow, or too wide to fit in any other tube.
Re: PT-18 MRP F 4th Valve Slides
Posted: Thu Apr 02, 2015 5:52 pm
by apsapienza
Yup, first thing I tried fixed it. Top slide was in backwards.
Thanks!
Angelo "I should read the suggestion right the first time"
