Leather burnisher, blueprints anyone?

[Mocivnik]

@RockyAussie: umm..with the spike, you can get pretty close aswell...but the "cutting" speed is higher here aswell.

 

@JLSleather: Jup.

[Matt S]

I use a standard 2950RPM bench grinder motor on my Nigel Armitage/Just wood burnisher. Working diameter is about 2"/50mm. Yeah it's fast, maybe just on the high end of acceptable", but it works just fine and the price was right.

[koreric75]

21 hours ago, JLSleather said:

Blueprint only necessary if you are mass-producing something.  Stick a piece of wood in a drill chuck, and make some grooves with a gouge or file, sand it right in place.  Obviously, for mounting on a bench or pedestal grinder, you'll need an internal thread to suit the arbor.

did similar, i used my dremel and the "screw on" post for buffing pads to turn the little wooden knobs that are flat with raised edges, it takes a few seconds to swap one out for another and i can control the speed to suit the material.  I have a drill press,  and a 24" section of oak dowel "closet rod" just haven't chopped and put a gouge to it yet...the dremel takes up way less space, but i have to hold the material and the dremel .  I had an idea  awhile ago to use a variable speed router mounted in a benchtop router table with a turned groove to do belts and sand edges...you could adjust the fence and the height with the table and router adjustments, just haven't tried it out yet.

[bullmoosepaddles]

@JKHelms I hope you don't mind. What is the left disk on your grinder? It appears too be leather, if my eyes are not lying to me. Makes me curious.

Thank you

Gene  

[Mocivnik]

 

2 hours ago, Matt S said:

I use a standard 2950RPM bench grinder motor on my Nigel Armitage/Just wood burnisher. Working diameter is about 2"/50mm. Yeah it's fast, maybe just on the high end of acceptable", but it works just fine and the price was right.

Yeah, same here. All I can get, has 2950 RPMs, but I will regulate it with a dimmer (as I regulate all my resistive and inductive burdens).

I can get a benh grinder of 350W for around 45€ (40GBP or 50 usd), which I think it's reasonable price.

2 hours ago, koreric75 said:

did similar, i used my dremel and the "screw on" post for buffing pads to turn the little wooden knobs that are flat with raised edges, it takes a few seconds to swap one out for another and i can control the speed to suit the material.  I have a drill press,  and a 24" section of oak dowel "closet rod" just haven't chopped and put a gouge to it yet...the dremel takes up way less space, but i have to hold the material and the dremel .  I had an idea  awhile ago to use a variable speed router mounted in a benchtop router table with a turned groove to do belts and sand edges...you could adjust the fence and the height with the table and router adjustments, just haven't tried it out yet.

So did I, but I really dislike the dremel to use for this. I don't find it steady enough in my hand, so I'm into something more rigid.

[Matt S]

2 hours ago, Mocivnik said:

Yeah, same here. All I can get, has 2950 RPMs, but I will regulate it with a dimmer (as I regulate all my resistive and inductive burdens).

I can get a benh grinder of 350W for around 45€ (40GBP or 50 usd), which I think it's reasonable price.

So did I, but I really dislike the dremel to use for this. I don't find it steady enough in my hand, so I'm into something more rigid.

What dimmer do you use for an inductive load? My bench grinder has a brushless/induction motor, which I have read is very difficult to control the speed without powering it through a variable-frequency drive.

I have bought and built inexpensive Dremel burnishers. I don't like them because it doesn't take much of an imbalance in the wheel to cause a lot of vibration. With a bench-mounted burnisher a small amount of imbalance is counteracted by the mass of the bench it's bolted to. Further, with the cheap Dremel clones I have the speed is way too fast, and because of the simple circuitry you lose all power when turning the speed down.

[Mocivnik]

Actually, a very regular dimmer. 

The one which is for the light, but you have to be careful, that in the datasheet (or just on the packaging) it shows that its availible for R, L and RL loads. 

But sometimes, you have to change the original triac for a better one, as the m9tor at the start can draw up to10 times or more current than regulary does. 

I use the dimmera for ~5€ and switch a triac for another 1€ and e-voila

Oh, and not to forget to mention, with dimmer, its not very accurate regulation, but its a cheap one. frequency regulators cost couple of hundreds of € each and its an overkill for this application. 

And yes, I agree 100% with dremel-bench grinder point of view. 

Edited September 12, 2018 by Mocivnik

[JKHelms]

5 hours ago, bullmoosepaddles said:

@JKHelms I hope you don't mind. What is the left disk on your grinder? It appears too be leather, if my eyes are not lying to me. Makes me curious.

Thank you

Gene  

It’s a series of scrap leather discs I cut and glued together to use for stropping my cutting tools.  

Works pretty good.

[Matt S]

24 minutes ago, Mocivnik said:

Actually, a very regular dimmer. 

The one which is for the light, but you have to be careful, that in the datasheet (or just on the packaging) it shows that its availible for R, L and RL loads. 

But sometimes, you have to change the original triac for a better one, as the m9tor at the start can draw up to10 times or more current than regulary does. 

I use the dimmera for ~5€ and switch a triac for another 1€ and e-voila

Oh, and not to forget to mention, with dimmer, its not very accurate regulation, but its a cheap one. frequency regulators cost couple of hundreds of € each and its an overkill for this application. 

Interesting, I'll try a lamp dimmer. I'll look for one rated for inductive loads. I have a motor that I don't mind risking for the sake of an experiment.

I agree, a VFD is overkill for a burnishing machine but it's what an electronics engineer advised me was the only electrical option for slowing an induction motor (other than modifying the coils or adding a physical brake!).

[gigi]

I've also made a sketch for a burnisher a while ago, with different type of grooves, bought the wood but never completed this project so I don't know how good it works :