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Neck bolt inserts
http://luthiersforum.com/forum/viewtopic.php?f=10101&t=47314		 Page 1 of 1
Author:  Ruby50 [ Sat Feb 20, 2016 9:54 pm ]
Post subject:  Neck bolt inserts
I am making my first neck (ukulele) and am installing my first threaded inserts for neck bolts. My problem may be that I am using Osage Orange which is quite hard, but I can't seem to get the insert's threads started. Here are some shots of my set-up, and there is text below each picture.

https://www.flickr.com/photos/ruby1638/24791691049/in/album-72157664721991842/

Any ideas? Much thanks

Ed
Author:  meddlingfool [ Sat Feb 20, 2016 10:23 pm ]
Post subject:  Re: Neck bolt inserts
Try using the drill to drive them in so you can get downward pressure. That's what I do. Btw, with those inserts, the slot is supposed to go down. It's a chip clearer, not a screwdriver slot. Or so I understand. I don't like those inserts very much, I dumped them.
Author:  Ruby50 [ Sat Feb 20, 2016 10:39 pm ]
Post subject:  Re: Neck bolt inserts
MF

I did find a website that said to install with the slot down, but Rockler sells these and says to use a screwdriver in the slot, and these people:

http://www.ezlok.com/inserts-for-wood

make them and they, too, say to use a screwdriver in the slot, so I am confused. What you say makes sense, but I have installed these things in plywood for jigs a while back and they went in real easy. I have thought of the pressure you can get from a drill press, but It will take a while to jig it up to give it a try.
Author:  johnparchem [ Sat Feb 20, 2016 10:52 pm ]
Post subject:  Re: Neck bolt inserts
On the web site http://www.ezlok.com/inserts-for-wood the top brass one on the web site is too fine threaded; it is not good for end grain. There exits another brass one that has looser threads. Look at the ones on the LMI site http://www.lmii.com/products/mostly-not-wood/truss-rods/neck-parts/bolt-on-neck-inserts

I have been using the hex derive one in the middle of the szlok website.
Author:  Clay S. [ Sat Feb 20, 2016 11:23 pm ]
Post subject:  Re: Neck bolt inserts
I prefer the inserts with the broken thread - which ezlok calls knife thread. The type I use is some sort of pot metal I think.The body of the insert is slightly tapered and I use a drill bit slightly larger than the diameter of the wide end.
I don't like the inserts with the fine continuous threads like you are showing in your picture. They are made of stronger metal, but don't seem to hold as well.
Author:  Aaron O [ Sun Feb 21, 2016 2:11 am ]
Post subject:  Re: Neck bolt inserts
Agree with most of the comments, starting with you're installing it backwards. And for end grain, you may want the inserts with coarse thread (as mentioned - LMI type).

Woodcraft has a T-handle installation tool; didn't think it was necessary, and while I can do without, it works well.

One trick I started doing recently after drilling the hole for the insert is to run a step drill into the hole and open up the top 1 "step" off the step drill bit. This sets the open slot section of the insert square into the hole in the end grain.
Note: be sure to blow out the chips that are cut by the open end of the insert. As stated, it is NOT for a screwdriver.
Author:  MaxBishop [ Sun Feb 21, 2016 7:31 am ]
Post subject:  Re: Neck bolt inserts
Rockler has a driver for this type of insert. It is hex drive with the end that goes into the insert having two tabs that fit into the slots. I use a ratcheting driver and have never had a problem. But then my necks/heels are Spanish Cedar.

Max
Author:  Tom West [ Sun Feb 21, 2016 8:28 am ]
Post subject:  Re: Neck bolt inserts
Wonder if your hole is bigger then the root diameter of the thread. With wood this hard you should not need full ingagement of threads. I would try a couple of test pieces with varying size hole to find out what works. Remember most times these are installed in much softer wood.
Tom
Author:  Dave Higham [ Sun Feb 21, 2016 8:52 am ]
Post subject:  Re: Neck bolt inserts
I’ve used threaded inserts like the ones you have in all the instruments I’ve made (only about 12 though) and never had a problem with them.
My thoughts are as follows:
On the E-Z LOK brass insert you show, the slot IS meant for driving the insert in. It’s only a chip clearer or thread cutter if it goes through the threads, and the example shown doesn’t.
http://www.ezlok.com/inserts-for-wood

They even have a tool for installing the inserts that uses the slot.

If the slot cuts through the threads, you can insert it slot-down but if the wood is very hard it may jam half way in and then you can’t get it out again.

What I’ve done with very hard wood (I understand osage orange to be very hard, no wonder you’re having problems) is to turn an insert into a tap by cutting grooves lengthwise with a hack saw. Screw this in in stages, backing off now and again as you would when tapping a thread in metal and then screw in your insert. I also wick in a little thin CA around the insert once it’s in.

The other thing I would do, if at all possible, is not install the insert into end grain. Drill the biggest hole you can through the neck/heel front to back and glue in a hardwood dowel, usually beech, and make sure your insert goes through this.
Author:  printer2 [ Sun Feb 21, 2016 9:17 am ]
Post subject:  Re: Neck bolt inserts
Quote:
What I’ve done with very hard wood (I understand osage orange to be very hard, no wonder you’re having problems) is to turn an insert into a tap by cutting grooves lengthwise with a hack saw. Screw this in in stages, backing off now and again as you would when tapping a thread in metal and then screw in your insert. I also wick in a little thin CA around the insert once it’s in.


Exactly what I did.
Author:  Mike OMelia [ Sun Feb 21, 2016 10:24 am ]
Post subject:  Re: Neck bolt inserts
What I do: clamp my neck alignment jig to my drill press table. Put a threaded shaft in the chuck with two locking nuts. Screw the threaded insert onto the threaded shaft up to the nuts and lock. Lower the chuck to the pre-drilled, properly sized hole. Turn chuck by hand. Once well started, I use an open ended wrench (I said, a wrench! A wrench!) to finish. Perfectly aligned every time. Someone here on this forum suggested it. If u don't have a drill press, then this obviously won't help. If you don't have a neck alignment jig, u can make similar with two pieces of plywood joined at 90 deg, some truss slot alignment pins, and some hand clamps. The wood hardness will not matter.
Author:  kencierp [ Sun Feb 21, 2016 10:56 am ]
Post subject:  Re: Neck bolt inserts
Tower Hobbies sells the proper course thread thin wall brass insert in small quantities --- using the larger OD versions will tend to be problematic. Our fixture totally captures the tenon to eliminate the possibility of splits. We use a hand drill and an inexpensive drill alignment tool from Harbor Freight. As noted the slotted end of the insert is a self tapping feature. The installation tool is a threaded rod (cut off bolt) and two nuts that lock up to push the insert into the pilot hole. We apply CA to help prevent spin out.


http://www3.towerhobbies.com/cgi-bin/wt ... LXK034&P=6


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Author:  Mike OMelia [ Sun Feb 21, 2016 11:20 am ]
Post subject:  Re: Neck bolt inserts
That's pretty clever Ken
Author:  Ruby50 [ Sun Feb 21, 2016 1:48 pm ]
Post subject:  Re: Neck bolt inserts
Thanks all

My drill press table does not spin 90°, so I jigged it up and used a wrench with down force from the chuck to get the thing to go in. More hassle than I was hoping, and the next time I do a uke with a hard neck I might just do a french screw/hanger bolt instead of the insert.

Ed
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