I want to create the "Best Sanding Blocks Ever"

My long AFS block has two 3/16 rods and one 1/4” rod. Flex is adjusted by removing rods. All three rods makes it quite stiff.

Don
Thanks. That is what I suspected, that 3/16" alone, at that length, would not be stiff enough.
Also thinking that on the shorter blocks, 8" and 4", I would drop down to 1/8" rod, or maybe (1) 3/16' and (2) 1/8"
 
  1. What do you think of the overall design? Is this a tool you would like to have?
  2. What about the width? Should I increase it a bit, closer to the standard width of PSA sandpaper?
  3. What lengths of blocks are required for an initial set? Planning 8", 16" and 24". Are 4" and/or 35" required?
  4. Does the flexibility look adequate?
  5. What are your impressions from the logo?
The width of a durablock is 2-5/8". Personally I think 2-1/2" would be ideal. I do like that I can roll the edge of the paper over the block edge. 1/16" per side with the durablock just isn't enough.

I think the 3 lengths are great place to start. I have a full set of flat durablocks and use those three sizes. They have a 5-3/4 I also use quite a bit.

Flexibility may become considerably less once it is bonded to the polycarbonate or acrylic. I don't know if that's an issue though. If it was, possibly you could decrease the thickness of the hard plastic or the profile height of the molded rubber.

Again regarding bodywork, I am just an amateur. I am a seasoned self-employed tool designer. I wish you the best with your venture.
 
Folding the paper over the edges only works on flat blocks, when they flex it flips the paper back flat anyway.

The only time I've ever really needed paper folded over the edge was with small blocks for detail sanding, usually on a custom block with the edge rounded to match the detail I'm sanding.
 
The rods on my AFS blocks are .157" diameter and the steel plate is 2.68" wide compared to the paper I have witch is 2.78" wide. If I center the paper, there's just enough overhang that I can use the edge to sand a concave fender like on a C2 corvette.
 
The width of a durablock is 2-5/8". Personally I think 2-1/2" would be ideal. I do like that I can roll the edge of the paper over the block edge. 1/16" per side with the durablock just isn't enough.

I think the 3 lengths are great place to start. I have a full set of flat durablocks and use those three sizes. They have a 5-3/4 I also use quite a bit.

Flexibility may become considerably less once it is bonded to the polycarbonate or acrylic. I don't know if that's an issue though. If it was, possibly you could decrease the thickness of the hard plastic or the profile height of the molded rubber.

Again regarding bodywork, I am just an amateur. I am a seasoned self-employed tool designer. I wish you the best with your venture.
Thanks. The overwhelming consensus is to make the blocks 2 5/8" like every other block. Think I'm going with that, many good cases made for why that is important.
Pretty sure I will launch with 8", 16" and 24" and then add other lengths later.

Interesting that you are a tool designer, I imagine you understand what I am going through, trying to make something great and incorporating the feedback. Fun stuff!
 
Interesting that you are a tool designer, I imagine you understand what I am going through, trying to make something great and incorporating the feedback. Fun stuff!
Yes it is fun for some of us. I love to make things. Trouble is, I spend in an incredible amount of time contemplating the best approach for everything I design. One thing I have learned is it is easy to get tunnel vision and missing the obvious. Asking for feedback and having an open mind as you are doing can be quite valuable.
 
I've asked this before, but how do you control the center of a 36" block? How does the block not sand more in the areas where your hands are and less in the other areas, mainly the center?
I have a 30" durablock and am reluctant to use it for that very reason.
 
Ok I broke out my vernier calipers and here’s what I got on my ABS block

2 rods .187” diameter
1 rod .251” diameter
Width 2.685”
Steel base is .014” thick

I would estimate tolerance on above to be +/- .0015” :)

Length roughly 30”

Don
 
Update: New CAD files done for blocks 2 5/8" wide per the feedback I received. Now working on bids for tooling design and for manufacturing.
Different length blocks will have different hardness factors, and different rod diameter configurations. It is not simple.

Should have it finalized in about 2 weeks.

FYI, I am getting "schooled" on domestic vs. offshore work. My intent was always "Made in the USA."
For example, creating the injection molds for each size is ~$3K each offshore. It is $100K+, each, domestically. Seriously?

I'm seriously conflicted about this. I'm a patriot, a veteran, and I want to support the US economy and workers. But that price gap is a show stopper.

I may have to have the tooling and initial production run done offshore, and then work to bring the tools and manufacturing onshore.

I know Made in the USA is a big deal to most of you, so I wanted to be transparent about this.

The project economics have to work.

Your thoughts?
 
Update: New CAD files done for blocks 2 5/8" wide per the feedback I received. Now working on bids for tooling design and for manufacturing.
Different length blocks will have different hardness factors, and different rod diameter configurations. It is not simple.

Should have it finalized in about 2 weeks.

FYI, I am getting "schooled" on domestic vs. offshore work. My intent was always "Made in the USA."
For example, creating the injection molds for each size is ~$3K each offshore. It is $100K+, each, domestically. Seriously?

I'm seriously conflicted about this. I'm a patriot, a veteran, and I want to support the US economy and workers. But that price gap is a show stopper.

I may have to have the tooling and initial production run done offshore, and then work to bring the tools and manufacturing onshore.

I know Made in the USA is a big deal to most of you, so I wanted to be transparent about this.

The project economics have to work.

Your thoughts?
Treat the injection molded part as a component made offshore. Do the lamination to the base domestically and you have a made in USA sanding block. It’s done every day….

Over the course of my 35 year engineering career I saw injection molded parts move from North America to offshore due to cost. Tooling and component cost were the reasons.

Don
 
Treat the injection molded part as a component made offshore. Do the lamination to the base domestically and you have a made in USA sanding block. It’s done every day….

Over the course of my 35 year engineering career I saw injection molded parts move from North America to offshore due to cost. Tooling and component cost were the reasons.

Don
Thanks Don. That may end up being the way to go. Still need more information.
I've looked into the "Made in USA" criteria. It is regulated by the FTC and there are requirements to meet, which is a good thing.
There is a "made in the usa with imported materials" classification that is possible.

The whole point of my post was to be transparent about the challenges and my intent.
 
Durablocks are made in Taiwan as near as I can tell. Doesn’t seem to affect their sales volume.

Don
 
The 30x price differential between offshore and USA is something that needs to be looked into. I remember trying to buy some forged connecting rods for an Olds, the offshores were $400 and the USA ones were nonexistent. There was a guy that would whittle a set for me out of billet for 2K, which really isn't a bad deal for custom work, but man... What has happened to US?
 
Durablocks are made in Taiwan as near as I can tell. Doesn’t seem to affect their sales volume.

Don
Yep, loud and "proud."
20220802_170129.jpg
 
I don't care if the sanding blocks are made in a straw hut by barefoot workers......... START PRODUCTION!!!

I'd listen to Don, you're still selling an American made product.
 
Back in the 80's I was an independent owner operator truck driver, I hauled dozens of loads of shoes from the port in LA to TN, MO, and other parts of the midwest. that were complete except for the soles. American workers sewed the soles on with a "Made in the US" label attached to them. I'm talking about high dollar top tier dress shoes. $200+ a pair 40 something years ago. Just make some dang blocks, so I can buy a set!
 
Back
Top