Engine-Turning Aluminum

[Straightliner59]

I've been experimenting with different ways of creating an engine-turned finish for aluminum sheet. I have an X/Y table for my Dremel Work Station, so, the pattern isn't the issue. Rather it was the cutting medium that was the bugaboo. While re-reading Scott Colmer's thread/how-to/article on his technique, it dawned on me to use the sheets from my old MSC polishing kit, and replace those with new Micro Mesh sheets. I didn't seem to have any 1/8" dowels (although I swear I did!), so I turned down a cuticle stick, until it fit the 1/8" collet for the Dremel. I then cut and smoothed the other end, and attached a disc of 1800 grit polishing cloth to it with a dab of super glue (Loctite gel). Using a light touch, I was able to achieve these results. I just free-handed on this sheet, as an experiment. It's the most consistent swirls I've been able to create, as well as most hassle-free. I'm going to try it with plastic rod, but, I suspect that will melt, from generated heat, even given the light touch. I don't think any kind of metal would have enough "give". Anyway, I thought I would share the results, in case anybody else finds it useful!

[CabDriver]

Great results!  Looks like you nailed that effect! 

[Straightliner59]

2 hours ago, CabDriver said:

Great results!  Looks like you nailed that effect! 

I think the Micro Mesh makes it work--it has that nice, cushiony backing. Now, I need to pick up some 1/8" and 1/16" dowels! Thanks, Jim!

[89AKurt]

I've tried various things, this came out looking very convincing.

[Straightliner59]

On 5/31/2022 at 12:39 AM, 89AKurt said:

I've tried various things, this came out looking very convincing.

I know, Kurt, I'm really happy with it! Nothing I'd tried ever looked quite right. I really do think the backing on the Micro Mesh cloths is what makes the difference. It has a nice amount of "give", to it.

[Scott Colmer]

Nice upgrade, Kurt. Your test looks pretty good. 

For me the key to a really engine turned look is keeping the pattern straight and consistent. The guide I made was pretty involved. I've been hoping someone will come with a simpler method that gets the same pattern. Can you post a pic of the X/Y table you mentioned.

 

Scott

[Straightliner59]

1 hour ago, Scott Colmer said:

Nice upgrade, Kurt. Your test looks pretty good. 

For me the key to a really engine turned look is keeping the pattern straight and consistent. The guide I made was pretty involved. I've been hoping someone will come with a simpler method that gets the same pattern. Can you post a pic of the X/Y table you mentioned.

 

Scott

Here's the one I have. It's an inexpensive one, since I can use the mill for more precise work. It works well, for this. Sorry I can't seem to find better photos!

[Straightliner59]

1 hour ago, Scott Colmer said:

Can you post a pic of the X/Y table you mentioned.

Here's another shot of the table. Here, it's set up to punch louvers.

Edited July 9, 2022 by Straightliner59

[peteski]

Actually that XY table is not bad at all (for light jobs).  It is quite precise.

[Straightliner59]

2 hours ago, peteski said:

Actually that XY table is not bad at all (for light jobs).  It is quite precise.

It's worked well, to be sure. Especially for the price! 

 

[Bugatti Fan]

Small diameter slot drills or end mills are very good for this type of work.

Engineering suppliers should have them in stock.

[peteski]

1 hour ago, Bugatti Fan said:

Small diameter slot drills or end mills are very good for this type of work.

Engineering suppliers should have them in stock.

Drills and mills for producing machine-turned surface finish on thin sheet of metal!?  The tool needs to be something lightly abrasive that will gently scuff/scratch the surface (not drill a hole in it).

[Scott Colmer]

That's pretty interesting. I'm out of bench room, but what space opens up, that could be pretty handy.

[Bugatti Fan]

End mill and slot drill bits have a squared off end unlike a normal drill bit.

Lightly bringing them just to touch down gently onto  aluminium sheet does work ok having done this a few times. It does take a bit of practice to get a feel for the very slight pressure that needs to be applied for consistency. An X Y table is very good to use for this type of work for consistent spacing of the marks made.

[Straightliner59]

6 hours ago, Scott Colmer said:

That's pretty interesting. I'm out of bench room, but what space opens up, that could be pretty handy.

Yessir! It's proven to be very handy! It does have a fair-sized footprint, but I managed to get it into my tiny shop (about 7'x9')! I would certainly recommend it, if you can find the space.

[Scott Colmer]

Last night I had the occasion to break out the old prototype Engine Turning Guide to make a dash panel for my current project. I found a strip of soft back polishing cloth in with the guide. I guess I made the switch to that medium as well.

I had to figure out how to get the vertical spacing consistent. I used styrene spacers (seen on the left)  for the second and third rows and then trimmed the flashing sheet the same depth as the spacers for the 4th and final row. The horizontal spacing is determined by the strip of tape with guide points marked on it. 

Anyway, in about 20 minutes I had a decent dash panel. It might have been better to go with a smaller diameter turn, but that would have added time.

Scott

[NOBLNG]

It looks good Scott. Is that some thin aluminum or foil duct tape?

[Scott Colmer]

Foil duct tape. One roll lasts a lifetime.

[Straightliner59]

On 8/14/2022 at 8:57 AM, Scott Colmer said:

Last night I had the occasion to break out the old prototype Engine Turning Guide to make a dash panel for my current project. I found a strip of soft back polishing cloth in with the guide. I guess I made the switch to that medium as well.

I had to figure out how to get the vertical spacing consistent. I used styrene spacers (seen on the left)  for the second and third rows and then trimmed the flashing sheet the same depth as the spacers for the 4th and final row. The horizontal spacing is determined by the strip of tape with guide points marked on it. 

Anyway, in about 20 minutes I had a decent dash panel. It might have been better to go with a smaller diameter turn, but that would have added time.

Scott

I recall seeing your setup in the magazine. It seems to work pretty well! you're right about the foil tape. A roll will last forever, and, it's super-versatile! I just got a new assortment of Micro Mesh sheets, so, I can use the old ones, freely!

[Jurva]

Thanks Scott for the idea for this jig. Just made mine and I love the results. I used toothpicks with 1000 grit sandpaper for my polishing medium.

Sorry about the big pictures.

[Rick L]

On 7/10/2022 at 4:01 PM, peteski said:

Drills and mills for producing machine-turned surface finish on thin sheet of metal!?  The tool needs to be something lightly abrasive that will gently scuff/scratch the surface (not drill a hole in it).

Not if you have a z stop.

[Bugatti Fan]

Rick, to those readers on here who are not engineers you might have needed to explain what a Z stop is.

Basically there are three axes.   X axis is Horizontal Left to Right motion. Y axis is Horizontal Front to Back motion and the Z axis that Rick refers to is Vertical Up and Down motion. The Z stop would be to limit the down motion so that the tool makes very light but consistent marks on the material.

Edited April 22, 2024 by Bugatti Fan

[Big John]

Came across a great article on how to make and use one of the hand held engine turning guides in the January 2010 Model Cars magazine.  Very similar to the ones shown above. Turn and Burn as we'd said in the Nav!

[Straightliner59]

1 hour ago, Big John said:

Came across a great article on how to make and use one of the hand held engine turning guides in the January 2010 Model Cars magazine.  Very similar to the ones shown above. Turn and Burn as we'd said in the Nav!

That's Scott Colmer's! It is posted above!?