Re: [Harp-L] for hohner 270 deluxe owners, probably a small crew at most

[Vern <jevern@xxxxxxx>]

Because I have bought and used many 270s (but no Deluxes) in Hands-Free-Chromatics, I claim to know them fairly well.  I think that the slide-clearance problem was not addressed in the Deluxe design.

Hohner has never controlled the slide clearance very accurately.  I have measured this clearance on several harps with a depth micrometer.
It appears that they punch the "U-channel" blank accurately.  The next operation is to bend up the flanges.  The results of this operation are not very accurate.  IMO, they need another machining operation on the flanges to accurately set their height.

Without consistency of flange height, they had to allow enough flange height for sufficient clearance (.002" - .003") at the lowest flange height.  However, at the high end of the range, (as much as .010" of clearance), this resulted in a very leaky harp.  Depending on the luck of the draw, the buyer could get anything from a fairly tight to a fairly leaky harp.

Trying to grout under the reed plate and slide of a 270 with a factory slide is like weatherstripping the windows of a room with an open door.
Take the covers off a 270 and blow one note while standing in front of a mirror. Leakage through the slide will cause the valves on either side of the blown reed to lift.

I made a tool for scraping the excess height from the flanges to produce a consistent  clearance of .002" to .003".   I scraped the flanges of a number of U-channels that were un-needed to make HFCs.  I and everyone who used them said that they produced a good-playing harp.

Both Schackner and Tate addressed the problem in their books.  Because the operation they described is tricky and can ruin a harp if overdone, I doubt that many 270s were fixed.

There were two problems with 270 combs:
!. Nailed-on reed plates were a pain to work on.  This led to horrors such as bending the reed through the slot to make tuning excavations on the bottom surface..
2. Wood, especially on old harps, would swell, shrink, warp, split, and peel.  Use of a plastic comb in the Deluxe model should have remedied these problems.

Hohner 270 reed plates  from an old harp but placed on an aftermarket plastic comb with a doctored U-channel will make an excellent harp. Aftermarket valves can also be an improvement.

Vern








On Oct 20, 2013, at 2:10 PM, Joseph Leone <3n037@xxxxxxxxxxx> wrote:

> 
> On Oct 20, 2013, at 3:44 PM, JON KIP wrote:
> 
>> If there are any dissatisfied owners of Hohner Deluxe 270's out there, and it's admittedly a small group who even forked up the money to buy one.... It's my favorite, but there have been some mysteries involved over the years.... I think that, between dick gardner and me, we've figured out what to blame for the majority of the issues. 
>> 
>> In a word "the comb".....
> 
> It doen't have to be. If one were to use a piece of wood that is nearly vertical grain, the piece would be more stable. Trees are like people. No two are the same and therefore growth patterns differ from tree to tree. BUT, vertical grain from a straight part of a tree with NO limb bud roots interfering, is a fairly stable piece. One way to choose a good comb would be to remove a reed plate (something a store is NOT going to allow) and study the grain. 
> 
> I have never seen a 270 comb separate. Hairline cracks? maybe? but these are usually sealable. The more likely is to find 280 combs separate. That's because I have seen  them in two and even three pieces. There were no lock joints. The pieces were merely slapped together, glued, and pressed. The grains were 'book' matched. In other words the grains ran in OPPOSITE directions. This was done to prevent the combs FROM twisting, bowing, warping. Much like modern closet shelving. But if the glue fails, you have a split comb.
> 
> I prefer wood combs but I like them to be laminated. This way, like plywood, the individual slabs work against each other, none of them wins the battle, and the piece stays the same shape. OR you could seal the combs. Many solutions could be used. Some would fly directly in the faces of those whom have a klepto for 'toxic shock' possibilities. lol
>> 
>> ok, in two words, but you get it... (At this point I'd think that nobody on harp-L has much interest in this, being mostly diatonic folk, but I'll go ahead, since about two (2) people in the past have expressed interest in that particular instrument, if I remembered who they were, i'd have just emailed them)
> 
> You could, but I'm leaving for the gig at 5:30. 
>> 
>> IF anyone has an interest in how to make these instruments into really good three octave chromatics, feel free to email me and I'll pass on what I've learned, with Dick's help recently.
> 
> Three possibilities. 1... seal the comb (I used to use mineral oil or shellac). I no longer have to as I use laminated combs. 2... change the comb. I have one made from porous bronze (electric motor bearing). But brass or alum. would also be a candidate. 3... use laminated comb.  
>> 
>> the wooden comb. nature's time bomb.
> 
> No, only a percentage of them fail. Maybe 8.77%. A lot has to do with maint. 1.. NEVER leave them in a hot car or other hot locale. 2.. NEVER totally wet the comb. This includes living in Fla. where the humidity can get to 67.......thousand percent. 3.. NEVER let the comb get ultra cold. While Circassian Walnut and Pear trees DO grow in extreme climates, the trees were probably alive at the time and were able to hold their own moisture content regardless. 4.. NEVER let them completely dry out...and THIS  I Z  the number one cause of failure. 5.. NEVER remove both reed plates at any one time.  
>> 
>> mind you, this is NOT the explanation of why I TWICE killed perfectly good reeds by having them get caught on my shirt cuffs....
> 
> Ha ha, snagging reeds IS a danger. When working on chromatics you have any where from 10 to 16 reeds..on EACH side just looking to D I V E at any protuberance handy. It's like they have chosen that as their main job. I hardly ever take off more than one cover at a time. This way the side I am working on is always facing up and towards my face. And then I notice that Kinya Pollard always wears a short sleeved, impeccably clean, pressed khaki shirt. I'm sorry but I don't have shirts that fine. So I don't wear one. 
> 
>> I finally solved that issue, after my wife suggested that I don't really have to wear a full tux to tweak my instruments.... who knew?
> 
> Ah yes, French cuffs DO protrude. 
> smo-joe
>> 
>> jk
>> 
>> http://jonkip.com
> 
>