So sorry to hear of David's passing. He was a fine luthier, and his student model dulcimer helped hundreds of people learn the dulcimer without breaking the bank. I still have one as does one of my students.
Sincere condolences to you and your family, @folkfan. It's nice to hear from you but I wish it were for a different reason.
As a general rule, we might assume that VSL independent of other variables has some effect on volume and sustain, but the other aspects of design weigh heavier, I'm sure. It was probably once the case that baritones in general had longer VSLs, but there are several luthiers now (New Harmony, Folkcraft . . . ) making baritones with a 25" VSL. (After all, if Taylor can offer their GS Mini as an acoustic bass, then anything is possible.)
As a chord player, I find shorter VSLs much more comfortable. Yes, I can stretch to that 1-2-4 A chord on a dulcimer with a 28" VSL, but it feels like I'm stretching. That same chord on a dulcimer with a 25" VSL is just plain comfortable.
There are a few luthiers (Folkcraft, Terry McCafferty) who use the same design and make dulcimers with varying VSLs by moving the placement of the bridge (McSpadden moves the nut for the same purpose, but I'm a little skeptical of that approach). You might ask them what they've noticed about the effect of VSL on the volume, sustain, and tone. I have a 25" McCafferty, and I suspect that had I opted for the 25.8" or 27" model, I would have a wee bit more sustain, but I doubt the tone and volume would change much.
A harmonica my other I’ve made two Cigarbox guitars but found a long box in Hobby Lobby and made me think “Dulcimer”.
I’m really new to music,and not really sure what a key is,but I play on happily in ignorance!
Scale length is always a matter of personal preference. Three of my guitars have vsls of 25.5 inches and of course all those fret boards are chromatic. My banjos are 26.25 inch vsl. The length I prefer for the dulcimer at vsl of 27 although I have some shorter than that and longer than that. As to strings, I don't buy dulcimer string sets. I buy strings in bulk for the gauges I prefer, both ball and loop end strings. I also make custom strings from spools of piano wire. Prepackaged dulcimer strings are just plain steel strings and wound strings packaged for dulcimer builders (Folkcraft andMcSpadden, etc.) by string manufacturers who make strings for guitars, banjos, mandolins, balalaikas, hammered dulcimers, etc. So, I don't think there is really any benefit to a longer VSL. If you like the sound and feel of a longer VSL, go for it. If not, choose one that appeals to you.
Ken
"The dulcimer sings a sweet song.
To me, scale length has been hugely important dependent on what tunings and keys I want to play in. If you're a singer it is critical. This matters less when you plan to play by yourself, but becomes super important if you plan to play with other people, especially if the other folks are not only playing dulcimers.
My dulcimers and banjos have a certain narrow range of scale lengths because I have always played them with other people on other instruments, or have sung with them. On the other hand, my custom langspil I was able to have made in a longer scale to tune a key or two lower, because i knew i would only be playing it by myself and wanted a lower key 'mournful' sounding instrument.
That said, learning to be able to play in more than 1 or 2 tunings, or using a capo, will enable one to play in more keys on an instrument of any scale.
Sorry, to answer the question, personal preference. If'in you like that sort of sound go for it!
Hey, @salt-springs ! I have not yet reached out to Terry Pattison. I will probably do that this week. I appreciate the tip on the CGC. This weekend has been a blur, so I won't get it re-strung until later in the week. I'll definitely keep you posted. Thanks!
@hugssandi , so good to see you post again here on fotmd! 
Robin and KenL both said it so well.
I hope David is at peace, and that he will be remembered in the beautiful sound of hundreds of people playing his dulcimers for years to come. My wishes for comfort go out to his loved ones.
Sorry, to answer the question, personal preference. If'in you like that sort of sound go for it!
The "36" inch is at least a fifth lower. I.D. slacked it a note or two below that so no issue with string tension. (Long neck banjo strings) And another tune on a "36" inch...
Folkfan, you have my deepest sympathy. Dave was a friend to so many dulcimer players. His student dulcimer got so many folks started on our beloved instrument. His "travel" dulcimer was a unique innovation. He will be missed by so many people. I consider myself fortunate to have known him in this life.
Ken
"The dulcimer sings a sweet song."
Nate, listen to I. D. Stamper's long dulcimer for a possibility:
@hugssandi I'll be looking for a video from you on International Appalachian Dulcimer Day! 
Hey folks just wondering what reasons people might have for preferring a longer scale length. I started off building dulcimers around 28-30" VSL, having heard that longer dulcimers are louder. Over time I've gradually made them shorter to make long stretches more comfortable, the most recent one being 23.5"
To me the tone of a longer scale seems a little fuller, but maybe I'm just convincing myself of that one.
I also appreciate the ever so tiny bit of extra space that you get between the frets in the second octave. A big downside to long dulcimers that I've noticed is that the packs of strings designed for dulcimers will be at a much higher tension than typical when brought up to Dad tuning.
So anyway just wondering what some benefits are for long dulcimers compared to short ones. Whether it be in the sound characteristics, practical reasons, play-ability, just anything that you tend to prefer on longer dulcimers. More perspective would help me to figure out what VSL I want to build at going forward.
Thanks
Nate
@folkfan Keigh, my heart is with you and your dear ones. Dave was, truly, a good guy! I was fortunate to have had our paths cross a couple times. Your brother's beautiful instruments sing now for so many and will sing for years to come! Rest in peace, Harpmaker.
I wanted to let Dave's friends here at FOTMD know that Dave passed away at our sister, Barbara's home. He had been suffering from stage 4 lung cancer. Now he is no longer in pain. Keigh/folkfan
I would so love for folks to friend me on fb and flood my page with vids of you playing on that day! --Sandi Lowery
I'm curious, did you ever get in touch with Terry Pattison? Let us know how your re-string goes..if you take your time it should go just fine. BTW, if you want you can also tune down to CGG and reduce string tension and play DAA tab. If I remember there are a few video's on youtube that will help you a great deal until you get the hang of it. Give us a yell and we'll do what we can to give you a hand.
It seems John Henry has stabilized and may get to go home before the week's over. 
Mark & I love John and our hearts are with him and all of his dear ones.
John Henry is a truly wonderful and amazing person. He and his family are in my thoughts and loving wishes right now.
John's son Paul says that John is in hospital and is asking prayers for him at this time.
Ken
"The dulcimer sings a sweet song."
Thank you, Strumelia! I will keep that in mind. Gonna try to re-string it this weekend.
That's a sweet video, @alegre1. Thank you.
Thank you Dusty for the kind words! Linda 
really terrific @alegre1 . One of my absolute favorite things about the dulcimer, that a couple people brought up in this video, is the low barrier of entry. So many people who don't consider themselves to be musically inclined find joy in making music with a dulcimer. Many times folks have expressed to me that they don't consider themselves musical and as soon as they learn to put enough pressure on the fret to get a clean note, they're enjoying playing music. It's cool to have an ambassador such as yourself for our lovely instrument.
-Nate
That is mighty kind, Nate, but I'd call myself like the person you describe rather than an ambassador. I had given up hope of ever being able to play an instrument until I found the dulcimer in my late fifties and then it was love at first sound. I like that it will challenge me for the rest of my life but, as it does so, I still get to play songs! Best regards, Linda
Wonderful video, alegre1. Thank you for creating and sharing it.
Ken
"The dulcimer sings a sweet song."
Aw shucks, thank you! I had fun making it with these friends and for the new Tn. club
Wonderful video, alegre1. Thank you for creating and sharing it.
Ken
"The dulcimer sings a sweet song."
really terrific @alegre1 . One of my absolute favorite things about the dulcimer, that a couple people brought up in this video, is the low barrier of entry. So many people who don't consider themselves to be musically inclined find joy in making music with a dulcimer. Many times folks have expressed to me that they don't consider themselves musical and as soon as they learn to put enough pressure on the fret to get a clean note, they're enjoying playing music. It's cool to have an ambassador such as yourself for our lovely instrument.
-Nate
That's a sweet video, @alegre1. Thank you.
@alegre1 I enjoyed your "Why Play the Dulcimer" very much! I imagine it will help attract new people to mountain dulcimer because of the joys of doing so expressed by the folks in the video.
If you mean tabs for guitar chords, you can go to a website like ultimate-guitar.com then find a song you like. For example here is a link to 'Leaving on a Jet Plane by John Denver"
https://tabs.ultimate-guitar.com/tab/john-denver/leaving-on-a-jet-plane-chords-32979
at the bottom of the screen you will see a white box that reads
"FONT -1+1 CHORDS AUTOSCROLL TRANSPOSE -1 +1"
you can transpose the tabs to a key that is better suited to your dulcimer by clicking on the +1 to transpose it up a half step or the -1 to transpose it down a half step. For example if you found tabs in the key of E, but your dulcimer is tuned to D, you could click the '-1' button twice.
This chart might then help to translate the chords into dulcimer chords https://everythingdulcimer.com/tab/chord_chart_dad_major.pdf
I don't know of a way to directly convert the kind of tabs which show all 6 strings, other than to just convert those tabs into their notes, then convert those notes into dulcimer tabs. This can be quicker than you might think with a chart like this
As Lisa mentioned, your biggest obstacle at that point is the chromatic frets, which might not be a problem at all if your dulcimer has a lot of frets. Quite a lot of pop music is mostly diatonic so if you are willing to put in the time to translate the guitar tabs into their notes, then transpose those notes into a key you can play on your dulcimer, a lot of times its very rewarding, but sometimes it can be fruitless if you dont have the frets you need.
Hope this helps
-Nate
It will be a delight to see how you all celebrate the day! @dusty-turtle will be with a group and, perhaps, other friends will be, too. I'll be at my usual playing location (home) with my usual playing partner (Mark). 
Hi Robin and everyone who might be interested for International Dulcimer Day,
Hi Everyone, In case anyone might be interested in a "Why Play the Dulcimer" promo for your club, I've attached a link to a five minute video I made for a friend who is launching a new club in Middle Tennessee to help her attract new members. The file is too big to attach here, but here's a link from her library's Facebook page, and so I think you can save the video that way if you'd like to use it.
Happy Playing!
(Looks like you might have to cut and paste it into the URL space)
https://drive.google.com/file/d/1iiSRd9TtCUnwz5y2AwnEGp5j7MiTWpv6/view?fbclid=IwAR2qO49okapHt1G_C8pq6foVvjKYUUByAgSpQ_Xaknm5SBwleXxbrJr3qQU
I much prefer classic ukulele tab chords such as here: https://www.ukulele-tabs.com/ukulele-tabs-chords.html call be old fashioned but it just reads easier for me.
Those strings should work ok, but if the .012 strings for the melody course feel too stiff or are hard for you to press down, try using .010 melody strings, especially since your scale length is almost 28".
