Home Grown Burnisher

[Mechanic]

On 8/26/2017 at 6:12 PM, dikman said:

Not a cheap-skate (a term usually applied by people who are incapable of making their own "stuff" and are probably just jealous anyhow). I take a great deal of pleasure in fabricating my own gear, when possible. Guess it's how I was brought up.

I will spend several hours and buy a gob of tooling to build a "whatever", even if I could buy one for 30 bucks.

In this case, i wanted a burnisher, "right now".

Chucked up a chunk of oak closet rod, drilled & tapped for a 7/16" bolt.

Had to grind a couple of tool bits to cut the radius.

 

I just chuck it up in the vertical mill.

Nice having speed control with it.

 

It runs just a smidgee bit out of concentric. I consider it the "orbital action".

I should have through drilled and put a nut on both ends, but I was working with what I picked up on the work bench.

Edited August 31, 2017 by Mechanic

[dikman]

Good one. That's what it's all about . As for the "orbital action" I'm sure the leather won't care!

[Dwight]

When I built mine, . . . it went on the shaft first (after drilling all the way through of course), . . . and then went into the drill press.

Got a big cup of coffee, . . . hand full of files, . . . turned the old press on, . . . chopped, channeled, and filed until I got what I wanted.

Then took it to the shop, . . . little bit of smoother sand paper, . . . then finished it off with a coating of true to life virgin bees wax from my hive up in the corner of the yard.

Took some nasty old hard leather scraps, . . . and heated up the burnisher by pressing really hard on it, . . . and she slicked up really good.

May God bless,

Dwight

[DrmCa]

Hoping this helps someone!

If you are looking for a motor with very high RPMs, you can find one in a vacuum cleaner. Many of them usually run 10,000 RPMs. But they are low power, keep that in mind.

And if you are looking for a variable RPM motor, then you might find a combination of a variac with a lawnmower PMDC motor might be a good choice. The variac will provide variable voltage, the bridge rectifier will rectify it, and the PMDC will respond well to variable DC. Going between 20V and 150V on the variac gives a full range of PMDC motor RPMs and slightly above.

Do not use a variac with a powerful AC motor, as at low RPMs they will overheat: both the variac and motor. The variac will overheat as it uses same diameter wire along the entire range of coil, and the motor will overheat, as its impeller will not provide enough air flow at low RPMs, where current increases.

Edited August 31, 2017 by DrmCa

[bikermutt07]

It's the shopsmith for me, as soon as I can get it set up. This oneachine could be complete Overkill for what a leather crafter needs. Variable speed, lathe, disc sander, belt, strip or drum sander and all with a ⅝" collet. What more could you ask for?

[480volt]

8 hours ago, DrmCa said:

Hoping this helps someone!

If you are looking for a motor with very high RPMs, you can find one in a vacuum cleaner. Many of them usually run 10,000 RPMs. But they are low power, keep that in mind.

And if you are looking for a variable RPM motor, then you might find a combination of a variac with a lawnmower PMDC motor might be a good choice. The variac will provide variable voltage, the bridge rectifier will rectify it, and the PMDC will respond well to variable DC. Going between 20V and 150V on the variac gives a full range of PMDC motor RPMs and slightly above.

Do not use a variac with a powerful AC motor, as at low RPMs they will overheat: both the variac and motor. The variac will overheat as it uses same diameter wire along the entire range of coil, and the motor will overheat, as its impeller will not provide enough air flow at low RPMs, where current increases.

I can't speak to lawnmower motors, but a variac cannot be used to control AC single phase motors. The speed of AC motors is a function of frequency and the number of poles. As you lower the voltage, the motor speed will try and remain constant and the current will increase proportionally till eventually the windings fail. A big enough variac won't care, it'll just keep feeding the load till the motor burns up. Lower airflow may contribute, but the main cause is excessive current.

A variac should feed a rectified DC motor with no problems, but it would be cheaper to go find a used treadmill and take the motor and controls off of it.

You should have a good understanding of motor nameplate ratings, wire ampacity, grounding, and overcurrent protection if you're going to build something up from scratch. 

[480volt]

On 8/30/2017 at 7:44 PM, Mechanic said:

It runs just a smidgee bit out of concentric. I consider it the "orbital action".

Just out of curiosity, since you turned it on a lathe, how is it not concentric with the shaft that was in the chuck?

[dikman]

I would hazard a guess that tapping into the wood was slightly askew? At least, that's what's happened to me when I've used a similar process.

[DrmCa]

I too made a burnishing cylinder on a lathe, but I drilled and glued the wood onto the steel shaft first, then turned the wood dowel on the shaft, so it's perfectly concentric.

[JD62]

On ‎9‎/‎1‎/‎2017 at 1:11 AM, 480volt said:

 a variac cannot be used to control AC single phase motors. The speed of AC motors is a function of frequency and the number of poles. As you lower the voltage, the motor speed will try and remain constant and the current will increase proportional

You should have a good understanding of motor nameplate ratings, wire ampacity, grounding, and overcurrent protection if you're going to build something up from scratch. 

 You explained this perfectly