Msa Millennium Deck Thickness

[Brian Henry]

Could someone tell me how thick the carbon fiber deck is on the MSA Millennium pedal steeel.

[Douglas Schuch]

Brian,

I'm not much help, but here's what I can tell you - first off, they are not a solid layup - there is a core inside. I think it is foam, but can not swear to that. Under the deck, it is flat - so the thickness varies on my D-10 as the on the top it has the typical rise up for the E9 neck. Also, it's not flocked - I think it is the heavy carpet similar to what is used on some steel cases, or PA speakers on the bottom. So just sticking a tape measure there will not be very precise, but I get about 1/2" under the C6 neck. That was not done too precisely since it would be impossible to get a precise measurement without some disassembly.

I seem to recall that Maurice Anderson wrote about experimenting with different thicknesses before deciding on what they ended up using. The variation would be in the thickness of the core material, not the layup. Carbon fiber only gets it's weight benefits if properly laid up in a thickness designed to provide the needed strength with minimal excess.

Perhaps someone who has had one disassembled could give you more specific answers.

[Brian Henry]

Thank you Doug, I am thinking of making another lap steel. This time from carbon fiber and want to be sure it doesn’t flex and is thick enough. 1/ 2 “ is what I thought. I know this stuff is expensive, but I already have all the components on my current lap steel which is made of cherry wood. I would use them. So I think I need 6” x 36” x 1/2”
Perhaps some more folk will chime in.

[Douglas Schuch]

Carbon Fiber construction, particularly of smaller items like a guitar, are almost always vacuum-bagged. This gets you a total "wet-out" with the least amount of resin and thus keeps weight low and strength high. Extra resin does not add strength - only weight. Also, they typically are not just carbon fiber - other fiber materials are used. However, the amount of carbon used must be enough to handle the full load, as it is very strong in tension.

Using a sailboat mast as an example - masts need to not bend to the side too easily to be efficient. So one can add carbon fiber along each side - long strands oriented vertically (in the finished mast). Carbon is very strong in tension, so as the mast tries to bend from wind pressure, the carbon resists this. However, the carbon has to bear the full load - other materials have more elongation - so they are stretching and bearing very little of the load - only the stiff, not-elastic carbon bears the brunt of the load. If not enough, it will fail, and then the mast bends as if there was no carbon to begin with. Carbon Fiber is weak in compression - so the carbon on the opposite side of the mast (inside the radius of the bend) does not help at all, until of course, you tack and the wind is on the other side!

Carrying the mast example one step further - to have put carbon fiber as a web in the exact center of the mast running fore and aft would help - but not nearly as much as on the outside of the mast, where the tension is the greatest. Running a carbon web side to side would help a lot more - more of the fiber is where the greatest tension is - but since the outer edge of the web gets tensioned the most, it will tend to fail, and then the next strand, then the next... and so on. Putting ALL the carbon right where the tension is greatest - at the outer skin, along the side of the mast where it is widest - will provide the greatest strength (and yes, I have built a sailboat wing mast out of wood, plywood, and carbon fiber).

Using two skins, separated by a non-structural filler (foam or plywood, for example) is much stiffer than a single lamination - the same principle as I-beams for steel construction. I did not mention it, but the aprons on the Millennium are not cored - but strength there is not essential. In fact, no carbon is probably needed there - just regular fiberglass would be adequate.

The tension on, say, a Frying Pan type guitar is mainly caused by the strings wanting to bend the neck into a U-shape. Steel guitars aggravate this problems due to the strings being further from the neck material. It seems counter-intuitive, but carbon will add more strength to that neck if used along the back of the neck than on the fretboard side, which is undergoing compression, not tension. Stronger still would be to mold it as a single piece with a foam or light wood core.

Carbon fiber is rather stiff (for the obvious reasons) so does not handle tight radius bends nearly as easily as standard E or S Fiberglass.

So, in short, figure out where the stresses are that will affect your instrument (depends a lot on the design - console? frying pan? Double neck?) and then figure out how to incorporate the carbon so that it will provide the greatest strength against those stresses. Use regular fiberglass (or wood, or ?) for the other areas.

I would say it is a rather complicated project, and I'm not sure the stresses on a lap steel (except possibly the neck) are such that there are many benefits to carbon. If the goal is very light weight, it will be an expensive and difficult project for a one-off guitar.

PS - one other thought has occurred to me. If your instrument is mostly flat planes, you can buy sheets of carbon plus other material already laid up in sheet form. So, for example, a console steel could be built out of pieces of this material just joined at the corners.

If this is discouraging - then good! It is kind of meant to be!

[Bill Fisher]

Say, Brian. Why don't you have Douglas make your guitar. That's what I would do. He's a genius at this stuff. Great to have him aboard.

Bill

[Douglas Schuch]

Thanks for the compliment, but I'm not really that good - I know just enough to know I don't want to attempt it! And to give Brian some heads-up about concerns he will face. Also, I don't built much of anything anymore - I've gotten older and joints have gotten more arthritic, and stuff that was fun 5-10 years ago is a massive chore now. I'm planning on tackling a a simple wood cabinet for a 2x10 speaker cab in the next month or so - that's about as complicated as I get these days!

[Brian Henry]

Thank you Doug.as and Bill. I have been in contact with Dragonplate and I think they have what I need. I have assembled many lap steel and am familiar with the process.

[Brian Henry]

Doug, I meant to add that MSA may have some carbon fiber left over and I may be able to secure some from them also.

[Kyle Bennett]

The deck thickness on the MSA Millennium was 1.00" on the top deck and .750" on the bottom. The body was vacuum-bagged in a pressured mold. The body was filled with a foam core. The fiber was strategically laid up to control torsion, tension, and compression cause by the design of a pedal steel. The only reason we stopped production was due to the cost of a finished carbon cabinet. The Millennium cabinet was extremely strong and precise.

[Brian Henry]

Thank you Kyle for that important information. I appreciate your willingness in providing that information. I have always admired the MSA millennium and may get one. When I can. Thank you!

[Douglas Schuch]

Cool - great info from Kyle. Building a mold is not that difficult. Neither is building a vacuum setup big enough to handle a pedal or lap steel. For pedal steel, I figure the hard part was designing it so the mechanics all fit in properly and lined up. The reality, though, is it's not very cost-effective for a one-off instrument (although there are ways). Equally difficult will be figuring out a laminate schedule that provides more than adequate strength without going overboard (which adds cost and weight).

But for a pedal steel, there is no need - MSA did all the hard work! Prices on used Millenniums are absurdly cheap, IMO, for such an advanced instrument. For a lap steel using prefab sheets? Sure - with the right design, no reason it would not work. I look forward to seeing your finished project, Brian.