View Full Version : First "strap hanger"

Rob Grant
Oct-20-2004, 7:02am
Just finished an all (almost) Oz timber f-4 in time for the local music festival this weekend...


The top is Tasmanian "King Billy" pine. The neck is three-piece Qld. "Maple"/Cooktown Ironwood. The sides "Scented Maple". The back is Qld. "Walnut." The binding and peghead veneer is New Guinea Ebony. The fretboard is Cooktown Ironwood ("Red Ebony"). None of the above timbers are true walnuts or maples, they are all local rainforest timbers. If anybody wants scientific names, hit me next week.

The bracing is a self-designed combo of X bracing and tone bar. Looks sort of like a backwards "K" from above. So far it is superior in balance across the strings, tone and volume then any of my previous mandolins. Had to pry it out of the wife's hands to refine the setup tonight!<g>

Rob Grant
Oct-20-2004, 7:08am
Here's another of the back. There is no binding on the back. Queensland Walnut, especially from the butt of the stump, will not only consume my best bandsaw blades, but also nicely mark those big belt buckles that CW players like to wear!<g> In other words, it doesn't need the protection of binding.

Rob Grant
Oct-20-2004, 7:13am
Here's a heel shot with the "strap hanger." All that work, why would anyone want to run a bloody strap through all that hard yakka!<g>

Rob Grant
Oct-20-2004, 7:21am
Here's one of the side with the N.G. ebony pickguard.

This instrument is basically my own design. The only thing I didn't make or mill are the tuners and strings. The string length is 14.25". The tuners are Schallers. The strings GHS. Basic f-4 with no frills.

Thanks for letting me share it wid' youse'.

Rob, FarOutNorthQueensland,Oz

Rob Grant
Oct-20-2004, 7:28am
One more thing... The saddle is made with a material that consists of epoxy resin with powdered graphite as the filler. Looks like ebony, but harder. I cast a block of this stuff about two years ago and I finally got around to running a test on it with this instrument. Seems like good gear so far. Got enough left over for a lifetime's worth of saddles!

Oct-20-2004, 8:29am
I see you've been busy since your USA trip!

Jim Garber
Oct-20-2004, 8:55am
That is one beauty! How does the Cooktown Ironwood board compare with std ebony in terms of wear etc.


Oct-20-2004, 9:03am
A very unique F-4! #I was admiring your "heel" photo and the oval hole, and observed that your "King Billy" pine top seemed rather thick. #How thin did you carve/graduate it? And was it's thickness a factor in deciding to go with your unorthodox "reverse K" bracing?

Regardless, good luck with her "coming out" party this weekend!

Oct-20-2004, 10:25am
Aye, and she's a sweetie for sure, Rob-O! Great work, my friend! Really intrigued by your brace pattern from the earlier pix. If it sounds half as good as it looks, then you can say goodbye right now, 'cause Mando Maria ain't going to be letting go!

Rob Grant
Oct-21-2004, 2:42am
Arthur wrote:"I see you've been busy since your USA trip!"

Arthur; It was the stimulus of seeing and hearing those fabulous instruments in Benicia that gave me a bit of incentive to push my own envelope... thanks again for the hospitality.

jgarber; Cooktown Ironwood (Erythrophleum chlorostachys) seems to be comparable in wear to std ebony. I'm not exactly sure what the mechanism is, but the boards have a waxy feel when completed. I don't believe there is actually a natural wax or oil involved as I don't find it necessary to treat the timber surface when glueing. Some local was flogging this timber on the internet as "red ebony"... it is not related to Diospyros (ebony). One problem with using it is that the dust produced when working is very toxic.

pathfinder; The thickest point viewable at the soundhole is actually 5mm (>.25"). What might
be confusing in the photograph is that you can also see part of the Red Spruce bracing just below the hole. In general the center of the top is 5.5mm - 6.0mm. This graduates down to around 2.5mm-
3.0mm at the recurve. Fully loaded, the top shows a slight deflection around the bridge feet. King Billy seems to give me the best results when I obtain that deflection.

zeke; Damn, me thinks you're right again 'ol son. Maria is watchin' this instrument like a dingo with a pup. I reckon the only time I'll see it again is when she wants to put new strings on it!

Rob Grant
Oct-24-2004, 6:18pm
Just finished a full weekend of testing out the new f-4. Maria did a two hour session of eastern european dance tunes for an acoustic circle dance gig at the local music festival. This was in conjuction with an acordian, three saxaphones, one flute and a guitar... and I could hear the f-4!

Also managed to stick the f-4 in the hands of Andrew Clermont. Andrew is one of the top musicians here in Oz.
The instrument sounded fantastic in his hands, but then again, so would anything with strings!<g> Clermont liked the f-4, but suggested refining the intonation at the saddle.

Here's a quick pix taken of Andrew in "action" with the f-4...