Endpin Reamer

[360guy]

The suggestion that if you mess up the the endpin hole you need to replace the end block isn't so. I bought from my teacher about a 100 endpin blanks that you glue in place then start from square one.

What brought me to this link was my search to find anyone who might have tried one of the Chinese ebay bass reamers. I am usually suspicious of the quality in such tools but lately I've been installing endpins that are just in-between my other reamers and I thought this would finish off the job nicely.

Otherwise I think I'm looking at about 250. It's stretching the budget. The ebay one is 65 + 15 shipping.

Also anyone have any experience in spiral cut vs. straight ( in regard to the flutes)

[1st Bass]

If the taper is correct you almost can't go wrong. The reamer only has to cut wood, so if it is smooth and relatively sharp, it will work. Mine is of 4140 round bar, custom made by a machinist friend. After machining I had a metallurgical lab heat-treat it for me. Works like a dream. (Straight-flute, BTW)

I used the new reamer to make a shaper, so that the new endpin assemblies can be made to match the taper of the reamer, before reaming the hole to fit the endpin assembly.

All in all, it was an enjoyable project.

[eh_train]

Hey 360 guy,

I bought one of the $65 reamers. It works well enough, but might be a little shy of the diameter I need for my latest project.

I didn't read over all of the old posts to see if this was discussed, but I reduced an endpin plug previously using a lathe. I used the endpin rod, well tightened, in the lathe and had no trouble making the plug a little narrower while still retaining the shape.

Cheers,

Paul (eh_train)

[Cody Sisk]

Originally Posted by 1st Bass

If the taper is correct you almost can't go wrong. The reamer only has to cut wood, so if it is smooth and relatively sharp, it will work. Mine is of 4140 round bar, custom made by a machinist friend. After machining I had a metallurgical lab heat-treat it for me. Works like a dream. (Straight-flute, BTW)

I used the new reamer to make a shaper, so that the new endpin assemblies can be made to match the taper of the reamer, before reaming the hole to fit the endpin assembly.

All in all, it was an enjoyable project.

Jealous!

I'm still looking to network a good machinist friend, but I swear they're all hermits!

[vejesse]

How hard did that 4140 get? Usually that material gets no harder than Rockwell 50 c.

[james condino]

An alternative to buying the endpin reamer if you will only use it occaisionally is to befriend a local luthier who has one. I'll be the first to admit that I don't own one, and was actually thinking about it last night. For the once or twice a year that I need it, I go over to a friend's place that has one and drop a $20 bill to twist it for a minute or two. Nobody likes to loan out tools for free, but $20 for two minutes- sure, most agree to that, and showing up with their favorite malt beverage has proven a 100% success rate since I was old enough to legally purchase it...

For the more common light touch up jobs, I took a nice piece of hard maple, turned it to 17:1 on the lathe (at a public shop that cost $1 for a day's use) and then use double stick tape to hold some fine sandpaper to it. It works great and is a very accurate low tech solution.

For oddball one-off jobs, I've been known to buy a fancy tool , use it once, and then resell it up on Epay for what I have into it. Avoid cheap imported tools at any cost.

j.

[1st Bass]

Originally Posted by vejesse

How hard did that 4140 get? Usually that material gets no harder than Rockwell 50 c.

Sorry-- I don't recall-- they told me at the time.

You can get it pretty hard in thinner sections, but this was a 2" diameter round bar on one end, tapering to an inch on the other, so the cooling rate dictates what can be done...but as I mentioned earlier, even relatively soft steel would work fine, as you are cutting spruce, or willow, or whatever, parallel to the grain-- it doesn't take much.

Steel has to have alloying ingredients that broaden the temperature range within which martensitic grain formation can occur, if you want them to get really hard in thicker sections. Usually vanadium and niobium are the choices for that. I used 4140 because it was available for free, and I knew it would work.

The tool cost me nothing, looks and works great, and I am more pleased with it than I would be with one I purchased for $250. So...no regrets, here. My soundpost setter is 5160 spring steel--also home-made. Working on a curved sole scrub plane now, with a 316 stainless sole, and ASTM A36 carbon steel sides. Blade will likely be A6--just because I have some.

Haven't decided what to use for handles.

Fun stuff. :-)

[vejesse]

I would think if you search around you could get a round piece of A2 1.5" dia. and 12" long for $25 or so. Way less prone to thin cross section cracks, through hardened rc 62. 4140 might want to warp a bit, you'd want to leave some stock and grind it between centers after milling and hardening.

[1st Bass]

I'm sure you are correct. I don't need two reamers, but I imagine it would be worth doing otherwise. I had actually contemplated a hardwood reamer with a steel insert. But when my co-worker agreed to make the reamer of 4140, it was certainly good enough. I'm not a machinist, nor a toolmaker, by trade.

I simply had a bass that needed a new endpin assembly, and no reamer, so...

[vejesse]

I've messed around with making some wood cutting tools. Drill rod is cheap and you can simply use casenite and a torch to harden, then temper in your oven in the house. These 'quickie' tools will cut wood but a bass endpin reamer is a different story. You need a lathe, horizontal mill with indexer, an oven designed for use with air quenched steel, cylindrical grinder, etc. And experience. Any shop capable of making this tool would charge double what the Herdim tool costs. These tools need to be really hard to hold an edge in spruce end grain, rc 60 or more. Junk steel aint going to cut it.

With all that in mind I don't think $250 is too bad.