Official Luthiers Forum!

I need a steel shaft, 3/4" diameter, 30-36" long. Each end needs to be turned down and tapped for a 1/2" nut. Tapping length on each end should be 2". Balance is important.

I have looked around on the net, but not found what I want yet. mcmaster is too limited in their selection here.

Mike

Try the Yellow Pages for a machine shop.

Sounds like you're building a buffer... If so, some folks buy go-cart axles (don't know where from, but Google will help out.)
I had mine turned by a machinist & it was quite a bit more expensive that the go cart axles I read about... On this forum IIRC. Try the archives, you might get lucky.

http://www.mfgsupply.com/m/c/AZ1401-36.html?id=bpMg5eIy

Todd, you are a genius!

This is EXACLTY what I need. Keyed, threaded, etc.

I have something a bit more involved than just a buffer, but a buffer is part of it!

Thanks!!!

Mike

Ya know, now that you mention it, I remember Dan talking about about the Go-Kart axle buffer. ITs amazing how expensive a part can be until someone finds a common use for it (Go-Kart axles). Then it is just a commodity.

Mike (Thanks to Dan also)

I don't want to be a downer.....but with the full length keyway these shafts are essentially 3/4" diam or less. Can you buy them without the full length keyway?

_________________
Steve Walden
Aspiring Builder,
Bartlesville, OK

Here's another source, but they have full length keys also.

http://www.northerntool.com/webapp/wcs/ ... +93+544613

_________________
Horton, MI

A buffer should have one end with right-hand threads and the other with left-hand threads. This keeps the nuts from spinning off.

Although its been mentioned that a 3/4 shaft with the ends turned to 1/2 inch threads and 36 long doesnt work all that well (or at least wobbles) .. mine doesnt seem to. I run it with a 1/5 HP motor, and single 12 inch buff from SM at each end. I also do not have the left end left hand thread, but instead used nylon lock nuts to secure the buff(s). They havent budged in a couple years of use (about 25-30 guitars or so). Maybe not good enough for some, but I did mine in the cheap and pretty much couldnt be happier with its performance. With the 1/5 hp, it also bogs down if you really lay into it, so its kind of a no-think fail safe to avoid burning thru ... you never get too much pressure.

_________________
Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

How does a key way change the diameter? It is 1".

Yes, I thought about the reverse thread thing.

Mike

he is talking about stiffness .. I can see it being less than a true 1 inch rod, but not to the point where it becomes 3/4 or less ... there is a huge difference in cross sectional area between 3/4 and 1 inch ...

_________________
Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

OK, I have thought about the strength issue. It is true the shaft is keyed on BOTH sides. Here is some additional info. The center section +/- 7 inches will be "strenghened" with a 4" diameter wooden roller (keyed) and locked to the axle with locking hubs (google steel mini-hub). At +/- 10 inches, pillow block bearings will support the shaft. Locking shaft collars will hold the shaft in place. That leaves a little less than 8" hanging outside for the buffer wheels (may be a reason for going with a 40" shaft).

All of this will be driven by a 3/4 to 1 hp motor, 1750 rpm, pully ratio 2.5:1.

When using the sander, there will be no buffer wheels on the shaft (but it may not matter).

What do you think?

Mike

I would just start with a larger or partially keyed shaft instead of trying to add a splint to one.

It is a single shaft... the roller is not a splint, but part of the overall design.

Larger diameter (>1") go-kart axles do not appear to be available.

This device will function as a thickness sander and as a buffer.

The floor (sled) of the device rises up to (adjustable) to create thinner boards.

Mike

I am looking for some 1" Diameter pillow block bearings... I found these:

http://www.amazon.com/Buyers-Hydraulic- ... 151&sr=1-1

But, I am not sure what they mean by "hydraulic". The price is right...

Mike

This whole time, that's what I was afraid you were planning.

Some people might do it, I've seen some run a giant disc sander and buffing wheel on the same shaft. Those people are %(#$ing crazy.

Here's my advice.

One very, very key feature that I think is imperative to any buffer I would use is low torque, low inertia (or is that two key features? ). If I rake in to a buffing wheel super hard with a sharp edge, I want to be able to stop it. I want it to slow down when I bear down on it real hard. Putting a motor capable of driving a drum sander, added with the inertia that the drum itself will carry, and you're looking at a serious trebuchet shot to the floor if you catch a corner on that wheel. I think 3/4hp is ample for a 12-14" buffer, but your drum sander will probably need at least 1 to 1_1/2 range. Plus I run my 6" drum sander at about 1600rpm, and my 12" buffing wheels at around 700. I just don't see any way to consolidate them on one shaft without seriously compromising the main function of either or both.

I've seen dozens (not exagerating - literally dozens) of guitars, bodies, necks, shattered by being launched from an overpowered buffing wheel. My advice - these are two totally separate machines, with very different and very opposing priorities. Not good bed mates at all in my opinion. Disc sander at the end of a drum sander shaft? - now hat's a cool space saving idea. I sure wouldn't put a buffer there though.

_________________
Eschew obfuscation, espouse elucidation.

I have decided against the design. I will make two separate fixtures.

Mike

I do apologize Mike - I hope you didn't take offense at what I said. I'm not out to bash anyone's ideas - it's just that I've worked on buffers that were way over-powered, and they really scare the crap out of me.

Keep comin' with the ideas though. I can certainly see how that one sounds so appealing as a space saver, but whenever I've already learned the hard way , I like to try and spare others the same pains. It really does seem like a disc sander at the end of a drum sander would be a perfect match though - similar needs in both power and rpm.

_________________
Eschew obfuscation, espouse elucidation.