>
    > Some time ago there was some discussion on producing slide throttle
    > parts or complete units, I don't remember which, maybe both. Is that
    > going forward?
    >
    > If not, there is a machine shop owner who is also a member of our
    > EAA
    > chapter who might be persuaded to make the parts. He has a NC mill
    > and
    > lathe. Looking at the parts, could they be more economically
    > produced by
    > a NC punch press? Would punch press made parts be acceptable? I
    > asked
    > him about transferring the design info to his NC machines. He said
    > he
    > could use a dfx file. IGES would also be acceptable, but he prefers
    > dfx.
    > Since Rhino could produce both, it looks like a match to me.
    >
    > I don't want to step on anybodies toes, and at the same time I don't
    > want this effort to just languish. I have hopes that the slide
    > throttle
    > would be more acceptable to builders if they could buy parts, or the
    > whole assembly. So, I might be willing to up-front the materials
    > cost
    > and initial production run if it doesn't prove too expensive.
    > Provided
    > nobody else wants to do it.
    >
    > Doc Custer
    > Retired software engineer and sometime Audiologist
    > Building RV9-A. Fuselage
    >
    > Feel free Doc. Do us all a favor and put it into production.
    > Yes our first ones were NC punch press. Front and back plates
    > were 3/16th 6061T6 about the limits of the punch press.
    > Very cheap to make. On the order of $15 each.
    >
    > Here are some pictures.
    >
    > 3/16th thick square flanges could also be punch pressed.
    >
    > The 3/8th inch thick  Teflon slide needs to be milled, laser cut
    > or water jet. Whatever works best with Teflon.
    >
    > The 3/8th thick aluminum spacer between the plates also needs
    > to be milled or water jet cut. Too thick for the punch.
    >
    >
    > Paul Lamar ...No rotor no motor.
    >
    >
    > If made available this would be a big step in helping me and others
    > with
    > future implementation.  I hate to be so proletariat, but, what kind
    > of end
    > cost might we be looking at?
    >
    > Love the idea, I am much more of an "off the shelf" type of guy (ask
    > Mistral, since we bought their intake).  This would be great for
    > future
    > endeavors.  FWIW.
    >
    > All the best,
    >
    > Chris
    >
    > Christopher Barber
    >

   Cost is a difficult question. My formula is to take the per unit cost
   (materials, direct labor, i.e., machine shop cost, etc.) plus
   amortization for the set-up plus overhead. Amortization and overhead
   are the big questions. Overhead in this case means essentially storage
   costs (see below) as it dominates whatever else is included. The
   machine shop owner said for onsey-twosye NC doesn't make much sense as
   the set-up is labor intensive and you can do as well with a manual
   Bridgeport or equivalent. At the level of 10, NC begins to make sense;
   at the level of 25 NC is a clear winner. If there is enough demand you
   can schedule periodic (6 or 12 month) production runs ala Tracy's
   redrives and there is no storage costs because everything is sold in
   advance. If you have to make a production run and store the parts for
   several years things get more difficult. The bean counters say storing
   something for a year costs 25% to 40%. So if you have to make 25 sets
   that won't sell out for four years, you have a considerable storage
   cost in addition to the other costs. And the producer (me) might be
   stuck with a lot of unsold inventory, a considerable risk which I will
   have to evaluate at some point. Might be cheaper to not do NC which is
   a shame because NC makes consistently good, nearly identical, parts.

   So, to help me estimate costs, an expression of interest from the
   potential buyers would be helpful. No commitment, just a statement
   that if the price were right, I would buy one. Given this data I can
   come up with a projected price, which I will share with the group.
   This might generate more interest or conversely cause some to say no.
   It might take several iterations to arrive at a firm price.

   What should be included? I am assuming a slide throttle for a two
   rotor 13B or equivalent with the egg shaped holes in the slide. If
   memory serves, this would include the two aluminum side pieces, the
   Teflon slide, some sort of attachment gadget to control the slide
   (help needed here), the spacers, and the four(?) tube-to-sheet metal
   turnings. Is this list correct? Anything that I left out or should not
   be included, i.e., additions or deletions? The "kit" would also
   include drawings, photos and directions. Some fit and finish work may
   be needed ala Van's matched hole kits, especially if some of the parts
   are made on a punch press. Where the installation is specific for a
   given aircraft it will be for an RV 9 including the A version because
   that is what is available to me; the RV 6 and 7 have the same firewall
   and so the documents could be expected to apply to them also. If
   someone wishes to contribute photos and directions for different
   aircraft, I would be willing to duplicate the documents and distribute
   them with the understanding that I would have complete editorial
   freedom. At the present time I doubt that aircraft specifics will be
   required, but one never knows what will turn up. I **hate** unpleasant
   surprises! As you can see, I am approaching this as a group exercise.

   My next step is to try to get a good **estimate** of the per unit and
   set-up costs from the machine shop. With that in hand I will look at
   the response and come up with a first price iteration.

   My goal is not to make a bundle on this; "overhead" does not include
   profit or a living for myself. I am retired which means I no longer
   have to make a living.

   Why would I do this? Like Paul, it is much better than staring at the
   TV glop. Or gambling. Or ... well, you get the idea. Having said that
   my resources are limited and this effort will have to pay its own way.

   My major motivation is based on the conviction that the rotary is the
   best engine for aircraft use and the best way to promote the rotary
   engine for aircraft use is to make the process of installing the
   engine in the aircraft as painless and as free of Fear, Uncertainty
   and Doubt (FUD) as possible. The slide throttle effort is one piece of
   the larger solution; here is an off-the-shelf solution to the throttle
   problem.

   Well, this got a lot longer than I intended. AND it is important for
   everyone to know where I stand and what you can expect from me.

   Doc Custer
   Retired software engineer and sometime Audiologist
   Building RV9-A. Fuselage

Doc,

Please put me down for one of the 2 inch,

Regards,
Joe Graham

--------------------------------------------------------------
Doc the same plates will work for two inch or three inch
all you need change is the slide. Your CDs are on the way.

Paul Lamar

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