Author Topic: Tips for working with aluminum (Read 57024 times)

rvieceli · « **Reply #120 on:** May 28, 2023, 11:42 AM »

@festal Feeler gauges are wonderful things to have around. Shim stock is expensive. Feeler gauges are usually between $5-$10. Most closer to $5. Readily available at most outlets from Harbor Freight, Walmart, NAPA, Autozone.

Take the things apart and you have a bunch of shim stock. Can be stacked when you need an in between size etc.

https://www.harborfreight.com/feeler-gauge-32-piece-63665.html

Ron

Richard/RMW · « **Reply #121 on:** May 28, 2023, 12:08 PM »

Quote from: festal on May 28, 2023, 10:39 AM

Quote from: Richard/RMW on May 28, 2023, 10:05 AM
Quote from: Cheese on May 28, 2023, 09:50 AM
Hey Richard...what diameter O-flute cutter and at what rpm?

@Cheese there is a major bout of yapping about Origin and AL over on the SO forum, short answer is:

3/16" O-Flute bit
Plunge 100
Auto speed 125
Speed ~3
(Auto) passes between 1.5 & 1.7 DOC

This is a place where AutoPass really shines, ramping into the cut mostly eliminates the tendency for the cutter to grab and jerk Origin around.

Quote from: Cheese on May 28, 2023, 09:50 AM
The beautiful thing about that jig is you really don't have to worry about it moving precisely parallel to the disc because you're going to continue to grind until the hard stop contacts the front edge of the table which IS parallel to the disc.

Exactly. Combined with setting the fence from the disk using a gage block it ensures a precise, parallel result. More and more I need to idiot-proof everything I do, lest I figure out a new & innovative way to dumb something.

RMW
1.5 thou doc?
What gage blocks are you using?

Sent from my iPhone using Tapatalk

Sorry, Depth of Cut, but in mm not thou, so ~1.5mm per pass. AutoPass ramps into each depth consecutively until you hit the target. It's a fantastic time-saver in general and IMO indispensable when cutting AL.

I got several sets of cheap gage blocks in metric on Bangood or AliExpress, don't recall which. Augmented those with @rvieceli brilliant suggestion elsewhere to use feeler gages for <1mm shims.

Really bad video making its way to the cloud now, should have it cobbled together shortly. The hand model had the day off so remember, you asked for it...

RMW

festal · « **Reply #122 on:** May 28, 2023, 12:11 PM »

Quote from: Richard/RMW on May 28, 2023, 12:08 PM

Quote from: festal on May 28, 2023, 10:39 AM
Quote from: Richard/RMW on May 28, 2023, 10:05 AM
Quote from: Cheese on May 28, 2023, 09:50 AM
Hey Richard...what diameter O-flute cutter and at what rpm?

@Cheese there is a major bout of yapping about Origin and AL over on the SO forum, short answer is:

3/16" O-Flute bit
Plunge 100
Auto speed 125
Speed ~3
(Auto) passes between 1.5 & 1.7 DOC

This is a place where AutoPass really shines, ramping into the cut mostly eliminates the tendency for the cutter to grab and jerk Origin around.

Quote from: Cheese on May 28, 2023, 09:50 AM
The beautiful thing about that jig is you really don't have to worry about it moving precisely parallel to the disc because you're going to continue to grind until the hard stop contacts the front edge of the table which IS parallel to the disc.

Exactly. Combined with setting the fence from the disk using a gage block it ensures a precise, parallel result. More and more I need to idiot-proof everything I do, lest I figure out a new & innovative way to dumb something.

RMW
1.5 thou doc?
What gage blocks are you using?

Sent from my iPhone using Tapatalk

Sorry, Depth of Cut, but in mm not thou, so ~1.5mm per pass. AutoPass ramps into each depth consecutively until you hit the target. It's a fantastic time-saver in general and IMO indispensable when cutting AL.

I got several sets of cheap gage blocks in metric on Bangood or AliExpress, don't recall which. Augmented those with @rvieceli brilliant suggestion elsewhere to use feeler gages for <1mm shims.

Really bad video making its way to the cloud now, should have it cobbled together shortly. The hand model had the day off so remember, you asked for it...

RMW

Yep I remember reading about the feeler gauges as shim stock. Used it too

So you are using 0.03mm doc with auto pass?

Sent from my iPhone using Tapatalk

Richard/RMW · « **Reply #123 on:** May 28, 2023, 12:29 PM »

Quote from: festal on May 28, 2023, 12:11 PM

Quote from: Richard/RMW on May 28, 2023, 12:08 PM
Quote from: festal on May 28, 2023, 10:39 AM
Quote from: Richard/RMW on May 28, 2023, 10:05 AM
Quote from: Cheese on May 28, 2023, 09:50 AM
Hey Richard...what diameter O-flute cutter and at what rpm?

@Cheese there is a major bout of yapping about Origin and AL over on the SO forum, short answer is:

3/16" O-Flute bit
Plunge 100
Auto speed 125
Speed ~3
(Auto) passes between 1.5 & 1.7 DOC

This is a place where AutoPass really shines, ramping into the cut mostly eliminates the tendency for the cutter to grab and jerk Origin around.

Quote from: Cheese on May 28, 2023, 09:50 AM
The beautiful thing about that jig is you really don't have to worry about it moving precisely parallel to the disc because you're going to continue to grind until the hard stop contacts the front edge of the table which IS parallel to the disc.

Exactly. Combined with setting the fence from the disk using a gage block it ensures a precise, parallel result. More and more I need to idiot-proof everything I do, lest I figure out a new & innovative way to dumb something.

RMW
1.5 thou doc?
What gage blocks are you using?

Sent from my iPhone using Tapatalk

Sorry, Depth of Cut, but in mm not thou, so ~1.5mm per pass. AutoPass ramps into each depth consecutively until you hit the target. It's a fantastic time-saver in general and IMO indispensable when cutting AL.

I got several sets of cheap gage blocks in metric on Bangood or AliExpress, don't recall which. Augmented those with @rvieceli brilliant suggestion elsewhere to use feeler gages for <1mm shims.

Really bad video making its way to the cloud now, should have it cobbled together shortly. The hand model had the day off so remember, you asked for it...

RMW
Yep I remember reading about the feeler gauges as shim stock. Used it too

So you are using 0.03mm doc with auto pass?

Sent from my iPhone using Tapatalk

Nope, each pass is around 1.5mm. Depends on the final depth as AutoPass lets you set the # of passes, so if the final depth is 6mm and I select 4 passes, each one is 1.5mm.

RMW

Cheese · « **Reply #124 on:** May 28, 2023, 12:40 PM »

Quote from: Richard/RMW on May 28, 2023, 07:14 AM

@Cheese does the Festool angle grinder offer any benefit that justify the cost premium over a yellow or red one?

The handle orientation looks good for cutting but then it's sideways for most grinding, the opposite of common right-angle grinders.

None of my grinders have variable speed, but I'm not sure I miss/need it.

The first thing I noticed is how smooth it runs, it doesn't have that hand numbing vibration like the Milwaukee. The second was noise level. The Milwaukees have a lot more noise, difficult to describe but a combination of gear noise, a higher level of noise and at both higher & lower frequencies.

One thing to watch though is to thoroughly tighten whatever disc/item you put on the AGC because the brake is much more effective. I've had both a cut off disc and a Scotch-Brite disc come loose because the Festool comes to a halt in 1-1.5 seconds while the Milwaukee slowly takes 4-5 seconds to wind down.

The handle orientation can be easily changed because the head rotates 180º by removing 4 screws.

The reduction in rpm does make a big difference for battery life. On speed level 1 (4500 rpm) the AGC is rotating faster than a RAS 115 at maximum 4000 rpm.

I was removing mineral stains on stainless using Scotch-Brite discs. With a 4.0 battery I was getting about 30 min of run time. Lowering the rpm to level 1, the run time improved to almost double that.

For heavy grinding or cutting I'd set the speed back to max but would install a 5.2 battery instead. The 4.0 battery balances the AGC nicely and that's my favorite combination.

Richard/RMW · « **Reply #125 on:** May 28, 2023, 12:47 PM »

You were warned. The full process is:

Rough cut stock 1+mm oversized
Tighten the miter bar with the hard stop against the grinder face
Using gage blocks, set the fence to the final dimension (40mm in this case), plus 0.5mm shim, loosen the miter bar screws
Secure stock and grind the first edge, knock off the burrs
Rotate stock and secure using the 0.25mm shim to offset the second edge
Grind and deburr, which leaves you with the final dimension plus +/- 0.25mm
Lap to final dimension using 120G wet/dry and a surface plate

Last chance...
Really bad video alert

Stock prep:

Gage blocks & shims:

Rough stock:

Stock after < 4 minutes setting up & grinding:

Stock after 60 seconds of lapping:

I needed a 40mm gage block, thanks for providing the nudge to finally make it.

RMW

Richard/RMW · « **Reply #126 on:** May 28, 2023, 01:01 PM »

Quote from: Cheese on May 28, 2023, 12:40 PM

Quote from: Richard/RMW on May 28, 2023, 07:14 AM

@Cheese does the Festool angle grinder offer any benefit that justify the cost premium over a yellow or red one?

The handle orientation looks good for cutting but then it's sideways for most grinding, the opposite of common right-angle grinders.

None of my grinders have variable speed, but I'm not sure I miss/need it.

The first thing I noticed is how smooth it runs, it doesn't have that hand numbing vibration like the Milwaukee. The second was noise level. The Milwaukees have a lot more noise, difficult to describe but a combination of gear noise, a higher level of noise and at both higher & lower frequencies.

One thing to watch though is to thoroughly tighten whatever disc/item you put on the AGC because the brake is much more effective. I've had both a cut off disc and a Scotch-Brite disc come loose because the Festool comes to a halt in 1-1.5 seconds while the Milwaukee slowly takes 4-5 seconds to wind down.

The handle orientation can be easily changed because the head rotates 180º by removing 4 screws.

The reduction in rpm does make a big difference for battery life. On speed level 1 (4500 rpm) the AGC is rotating faster than a RAS 115 at maximum 4000 rpm.

I was removing mineral stains on stainless using Scotch-Brite discs. With a 4.0 battery I was getting about 30 min of run time. Lowering the rpm to level 1, the run time improved to almost double that. For heavy grinding or cutting I'd set the speed back to max but would install a 5.2 battery instead. The 4.0 battery balances the AGC nicely and that's my favorite combination.

(Attachment Link)

Thanks. I have the DeWalt 20V and know what you mean about the noise, it has a definite grinding-gearbox sound.

Funny you mention the effect of the brake, as my first thought when you mentioned the locking nut earlier is that I never use a wrench on the DW anyway, just the friction of the nut against the disk, which I grab and tighten or loosen by hand. Never occurred to me it could loosen itself that way.

Just idle curiosity anyways, I have so many 4-1/2" grinders that 2-3 are stored in the house. A guy can dream, right?

RMW

festal · « **Reply #127 on:** May 28, 2023, 01:04 PM »

Quote from: Richard/RMW on May 28, 2023, 12:29 PM

Quote from: festal on May 28, 2023, 12:11 PM
Quote from: Richard/RMW on May 28, 2023, 12:08 PM
Quote from: festal on May 28, 2023, 10:39 AM
Quote from: Richard/RMW on May 28, 2023, 10:05 AM
Quote from: Cheese on May 28, 2023, 09:50 AM
Hey Richard...what diameter O-flute cutter and at what rpm?

@Cheese there is a major bout of yapping about Origin and AL over on the SO forum, short answer is:

3/16" O-Flute bit
Plunge 100
Auto speed 125
Speed ~3
(Auto) passes between 1.5 & 1.7 DOC

This is a place where AutoPass really shines, ramping into the cut mostly eliminates the tendency for the cutter to grab and jerk Origin around.

Quote from: Cheese on May 28, 2023, 09:50 AM
The beautiful thing about that jig is you really don't have to worry about it moving precisely parallel to the disc because you're going to continue to grind until the hard stop contacts the front edge of the table which IS parallel to the disc.

Exactly. Combined with setting the fence from the disk using a gage block it ensures a precise, parallel result. More and more I need to idiot-proof everything I do, lest I figure out a new & innovative way to dumb something.

RMW
1.5 thou doc?
What gage blocks are you using?

Sent from my iPhone using Tapatalk

Sorry, Depth of Cut, but in mm not thou, so ~1.5mm per pass. AutoPass ramps into each depth consecutively until you hit the target. It's a fantastic time-saver in general and IMO indispensable when cutting AL.

I got several sets of cheap gage blocks in metric on Bangood or AliExpress, don't recall which. Augmented those with @rvieceli brilliant suggestion elsewhere to use feeler gages for <1mm shims.

Really bad video making its way to the cloud now, should have it cobbled together shortly. The hand model had the day off so remember, you asked for it...

RMW
Yep I remember reading about the feeler gauges as shim stock. Used it too

So you are using 0.03mm doc with auto pass?

Sent from my iPhone using Tapatalk

Nope, each pass is around 1.5mm. Depends on the final depth as AutoPass lets you set the # of passes, so if the final depth is 6mm and I select 4 passes, each one is 1.5mm.

RMW

Oh didn’t know you can do that deep per pass with shaper

Sent from my iPhone using Tapatalk

tsmi243 · « **Reply #128 on:** May 28, 2023, 02:00 PM »

Quote from: Richard/RMW on May 28, 2023, 12:47 PM

Tighten the miter bar with the hard stop against the grinder face
Using gage blocks, set the fence to the final dimension (40mm in this case), plus 0.5mm shim, loosen the miter bar screws

I get it now- it's not there for the actual cut. It's just a 3rd hand for setting the fence. That's a really good system.

How does that machine do on mild steel?

Richard/RMW · « **Reply #129 on:** May 28, 2023, 02:34 PM »

Quote from: tsmi243 on May 28, 2023, 02:00 PM

Quote from: Richard/RMW on May 28, 2023, 12:47 PM

Tighten the miter bar with the hard stop against the grinder face
Using gage blocks, set the fence to the final dimension (40mm in this case), plus 0.5mm shim, loosen the miter bar screws

I get it now- it's not there for the actual cut. It's just a 3rd hand for setting the fence. That's a really good system.

How does that machine do on mild steel?

The grinder is great on steel also. The disk is pretty well done, needs to be replaced which is the downside since it involves peeling it of and then cleaning adhesive using lacquer thinner. PITA.

Side note, did lacquer thinner get "improved" recently? My most recent gallon smells different.

RMW

festal · « **Reply #130 on:** May 28, 2023, 03:08 PM »

Quote from: Richard/RMW on May 28, 2023, 02:34 PM

Quote from: tsmi243 on May 28, 2023, 02:00 PM
Quote from: Richard/RMW on May 28, 2023, 12:47 PM

Tighten the miter bar with the hard stop against the grinder face
Using gage blocks, set the fence to the final dimension (40mm in this case), plus 0.5mm shim, loosen the miter bar screws

I get it now- it's not there for the actual cut. It's just a 3rd hand for setting the fence. That's a really good system.

How does that machine do on mild steel?

The grinder is great on steel also. The disk is pretty well done, needs to be replaced which is the downside since it involves peeling it of and then cleaning adhesive using lacquer thinner. PITA.

Side note, did lacquer thinner get "improved" recently? My most recent gallon smells different.

RMW

One more question lol. How close to the wheel is the base of the jig? Hard to tell in the video but it’s not touching the wheel?
Do you have any drawings and measurements of the jig?

Sent from my iPhone using Tapatalk

Cheese · « **Reply #131 on:** May 28, 2023, 03:25 PM »

Quote from: festal on May 28, 2023, 03:08 PM

One more question lol. How close to the wheel is the base of the jig? Hard to tell in the video but it’s not touching the wheel?
Do you have any drawings and measurements of the jig?

Richard mentioned a couple of thousandths.

festal · « **Reply #132 on:** May 28, 2023, 03:33 PM »

Quote from: Cheese on May 28, 2023, 03:25 PM

Quote from: festal on May 28, 2023, 03:08 PM

One more question lol. How close to the wheel is the base of the jig? Hard to tell in the video but it’s not touching the wheel?
Do you have any drawings and measurements of the jig?

Richard mentioned a couple of thousandths.

oops. missed it. appologies

festal · « **Reply #133 on:** May 28, 2023, 04:21 PM »

@Cheese does festool grinder work with 5" wheels or only 4-1/2?

Cheese · « **Reply #134 on:** May 28, 2023, 04:34 PM »

Quote from: festal on May 28, 2023, 04:21 PM

@Cheese does festool grinder work with 5" wheels or only 4-1/2?

Yup...check out this post for purchasing proper 5" guards.

https://www.festoolownersgroup.com/ask-festool/does-the-north-american-agc-18-ship-with-a-5-guard-or-a-4-12-guard/msg694048/#msg694048

Coen · « **Reply #135 on:** May 28, 2023, 04:35 PM »

Quote from: festal on May 28, 2023, 04:21 PM

@Cheese does festool grinder work with 5" wheels or only 4-1/2?

Haha, you gotta be kidding me Festool...

In Europe they have the AGC 18-125.... so guess what; for 125mm wheels.
On FestoolUSA they have the AGC 18-115... so that is 115mm

Same machine if you ask me

5" is ofcourse 127mm. I have no clue if you guys get 2mm less than what your wheels are sold as or that we get 2mm more

festal · « **Reply #136 on:** May 28, 2023, 04:41 PM »

Quote from: Cheese on May 28, 2023, 04:34 PM

Quote from: festal on May 28, 2023, 04:21 PM
@Cheese does festool grinder work with 5" wheels or only 4-1/2?

Yup...check out this post for purchasing proper 5" guards.

https://www.festoolownersgroup.com/ask-festool/does-the-north-american-agc-18-ship-with-a-5-guard-or-a-4-12-guard/msg694048/#msg694048

Perfect. Thank you. i guess i'll be getting festool grinder lol after i figure out the model numbers

Coen · « **Reply #137 on:** May 28, 2023, 04:58 PM »

Quote from: Cheese on May 28, 2023, 04:34 PM

Quote from: festal on May 28, 2023, 04:21 PM
@Cheese does festool grinder work with 5" wheels or only 4-1/2?

Yup...check out this post for purchasing proper 5" guards.

https://www.festoolownersgroup.com/ask-festool/does-the-north-american-agc-18-ship-with-a-5-guard-or-a-4-12-guard/msg694048/#msg694048

Lol, I should have not ignored the warning "there was a new post ..." warning.

Richard/RMW · « **Reply #138 on:** May 28, 2023, 05:41 PM »

Quote from: festal on May 28, 2023, 03:08 PM

Quote from: Richard/RMW on May 28, 2023, 02:34 PM
Quote from: tsmi243 on May 28, 2023, 02:00 PM
Quote from: Richard/RMW on May 28, 2023, 12:47 PM

Tighten the miter bar with the hard stop against the grinder face
Using gage blocks, set the fence to the final dimension (40mm in this case), plus 0.5mm shim, loosen the miter bar screws

I get it now- it's not there for the actual cut. It's just a 3rd hand for setting the fence. That's a really good system.

How does that machine do on mild steel?

The grinder is great on steel also. The disk is pretty well done, needs to be replaced which is the downside since it involves peeling it of and then cleaning adhesive using lacquer thinner. PITA.

Side note, did lacquer thinner get "improved" recently? My most recent gallon smells different.

RMW
One more question lol. How close to the wheel is the base of the jig? Hard to tell in the video but it’s not touching the wheel?
Do you have any drawings and measurements of the jig?

Sent from my iPhone using Tapatalk

Cheese nailed it.

No drawings, everything was made up on the fl. The stock is 1/4" by 4", the 12" disk can't handle anything much wider. Length is based on the table depth plus another 20mm or so. Slots start around 25mm in from the disk.

RMW

rvieceli · « **Reply #139 on:** May 28, 2023, 06:31 PM »

Before anyone asks, the reason the 12 inch sanding disk won’t handle more than 4-5.5 inches or so is control. Since the disk is spinning rather quickly, rotating around the arbor. On one side of the arbor the rotation is up away from the table. On the other side it rotates into the table. The rotation away from the table wants to pull the workpiece up as well. On the other side the rotation pins the workpiece to the table and makes it easier to control the interface with the sander and the piece.

That’s why you would see big disk sanders in pattern shops because of the increased workpiece size. Not uncommon to see 20 and 30 inch disks.

I’m running two 12s one for metal and one for wood. By I rarely work with bigger pieces.

These disk sanders come up fairly frequently on Facebook marketplace, they seem to have fallen out of favor for people using the belt ones instead.

If you have the space and the extra budget, I’d suggest at least a 20 in you want work with 6-9.5 inch stuff.

Ron

festal · « **Reply #140 on:** May 28, 2023, 06:55 PM »

ha i actually knew that lol

Richard/RMW · « **Reply #141 on:** May 28, 2023, 07:10 PM »

Quote from: rvieceli on May 28, 2023, 06:31 PM

Before anyone asks, the reason the 12 inch sanding disk won’t handle more than 4-5.5 inches or so is control. Since the disk is spinning rather quickly, rotating around the arbor. On one side of the arbor the rotation is up away from the table. On the other side it rotates into the table. The rotation away from the table wants to pull the workpiece up as well. On the other side the rotation pins the workpiece to the table and makes it easier to control the interface with the sander and the piece.

That’s why you would see big disk sanders in pattern shops because of the increased workpiece size. Not uncommon to see 20 and 30 inch disks.

I’m running two 12s one for metal and one for wood. By I rarely work with bigger pieces.

These disk sanders come up fairly frequently on Facebook marketplace, they seem to have fallen out of favor for people using the belt ones instead.

If you have the space and the extra budget, I’d suggest at least a 20 in you want work with 6-9.5 inch stuff.

Ron

Gets exciting quick if you slip across the center line...

I'd love a larger machine, even a second 12" for a different grit would be awesome. Just realized that, except for perhaps a couple routers, this is my oldest power tool.

RMW

Cheese · « **Reply #142 on:** May 28, 2023, 09:46 PM »

Quote from: Richard/RMW on May 28, 2023, 07:10 PM

Gets exciting quick if you slip across the center line...

I'd love a larger machine, even a second 12" for a different grit would be awesome. Just realized that, except for perhaps a couple routers, this is my oldest power tool.

Ya it does get exciting when traveling over the center line...you have a 1"-2" overtravel and then hold on. It gets worse the larger you go because of the moment arm.

I'd also like to have the space where I could have a pair of 12" discs and a pair of 4" x 48" belt sanders. I'd keep different grits on both machines and the process would be so much faster.

Richard/RMW · « **Reply #143 on:** May 29, 2023, 12:00 PM »

Just a final thought on this grinder. I recalled that the original purpose of truing up the front edge was more straightforward, quick & dirty 90 & 45 degree true ups.

Here's the finished 40mm by 100mm gage block. The import sets are great but it's nice to not need to stack up several blocks for common sizes like 1.5" & 40mm.

RMW

rvieceli · « **Reply #144 on:** May 29, 2023, 12:11 PM »

Richard I put a sled on mine that runs in the miter slot and has a stop that can be adjusted slightly to get it 90 degrees to the platter.

Ron

Cheese · « **Reply #145 on:** May 30, 2023, 09:25 AM »

Quote from: Coen on May 28, 2023, 04:35 PM

Haha, you gotta be kidding me Festool...

In Europe they have the AGC 18-125.... so guess what; for 125mm wheels.
On FestoolUSA they have the AGC 18-115... so that is 115mm

Same machine if you ask me

5" is ofcourse 127mm. I have no clue if you guys get 2mm less than what your wheels are sold as or that we get 2mm more

I purchased this US 576824 AGC 18-125 EB RA grinder but now realize it came with 115 mm guards. So @Coen do the AGC 18-125 grinders in Europe come with 125 mm or 115 mm guards?

Coen · « **Reply #146 on:** May 30, 2023, 09:47 AM »

125 as far as I know. My brother has one.

115 is exotic size here. It's all 125 or 230

Cheese · « **Reply #147 on:** May 30, 2023, 11:51 PM »

Quote from: Cheese on May 25, 2023, 10:10 PM

I received 3 Scotch-Brite™ 36 grit discs today. I tried out the glass fiber backed version which has a molded in 5/8-11 screw thread. It's very nice and very solid however, it is also very aggressive. That's not a big deal for steel items that will be powder coated, but it may be an issue for stainless issues left naked or for aluminum substrates. I'd like to see this item offered in a 60-80 grit version.

(Attachment Link)

All of these discs are 36 grit, 2 with the TN designation (Tinnerman nut) and one with the molded in 5/8-11 screw threads. The differences between the discs is they are manufactured from either Aluminum Oxide or Silicon Carbide abrasives.

The non-Tinnerman nut disc was initially my favorite because there is no tangential run-out of the disc. The Tinnerman nut version produces a tangential runout because of the way it's manufactured. There is a pricing difference of 50 cents between the different styles which could be an issue if thousands of these discs were used per year...think automotive body shops.

The molded thread version is really nice, it glides along the surface and it would be my go-to disc. I plan on trying the Tinnerman nut version tomorrow and see how that goes. I expect the Tinnerman nut version to produce a weird machining pattern because of its constantly changing depth dimension. These photos may help.

In order of viewing...the fiberglass backer version with molded in 5/8"-11 threads, the TN versions which obviously have a serious offset...we'll find out how that affects the performance.

(Attachment Link)

(Attachment Link)

(Attachment Link)

I know I earlier expressed some doubt with the way these discs would function because they do not align perpendicular to the grinder shaft axis. Happy to report I could not feel any unusual vibration or notice any aberration in the grind surface patterns. This disc performed exactly like the non-Tinnerman nut version and they are about 50 cents cheaper...could be a big deal for large quantity users.

I also noticed that these 3M Scotch-Brite discs put very little heat into stainless. That was a surprise. I used them at #1 speed on an AGC which is 4500 RPM. It enhanced battery life and produced a nice clean surface with little heat.

They are also very resistant to loading up. I used them to remove PL 400 and Dow Corning Silicone applied to stainless steel. They removed the residue with no drama...easy peasy. Maybe it was the lower RPM that made the difference because the stuff didn't melt and spread itself over the entire surface.

I'm very happy with their performance, just wish they made something in higher than a 36 grit compound. Think 60-80 grit...

rvieceli · « **Reply #148 on:** June 03, 2023, 12:42 PM »

@Cheese did you get those hook and loop 3M scotchbrite disks? Had a chance to use them yet? Curious about how they perform. Thanks Ron

Cheese · « **Reply #149 on:** June 03, 2023, 01:06 PM »

Quote from: rvieceli on June 03, 2023, 12:42 PM

@Cheese did you get those hook and loop 3M scotchbrite disks? Had a chance to use them yet? Curious about how they perform. Thanks Ron

Hey Ron, I received the Scotch-Brite discs, I'm just waiting for the back-up pad to arrive.

I tried placing a disc on the AGC grinder which lasted for about 5 seconds before the disc released itself and sailed under some lilac bushes.

I'm hoping the pad arrives today, if not, I just may dig out the RAS and see how that goes just to get a feeling of the kind of finish these discs will leave. The small area that was subjected to 5 seconds of the medium disc, produced a real nice blended surface.