Rex Krueger patreon

Behind the Scenes: Pin Manufacturing

🕑 Added 2021-02-25 13:11:31 +0000 UTC

Comments

Robert Dennett

I have an old Fine Woodworking book with an interview with Tage Frid where he was stating his preference for bow saws for joinery. Do you share his opinion? If so, where does one get blades? Most I have seen online appear to be kind of expensive or are intended for trimming trees. That leads me to another question: do tree trimming bow saw blades have any place outside of making firewood and, perhaps, timber framing?

Mark Diaz

It's a kit, so "assembling" the washer could be left to the user.

Mike

Great video on the insight into how these things get made. Taken from the perspective of someone familiar with the material being used and the unique challenges to manufacture the item is very interesting. I'm looking forward to seeing where this goes (and to ordering a saw kit!)

Michael Ross

4140, with electroless nickel plating. You can DIY that on a hot plate. (I've not actually DIY'd Ni myself, but I have seen it done.) Eliminate any square sharp inside corners and choose a single radius for those, whatever the machinist offers - if you can. It will be a stronger part. You can get a bead blast for greater strength. tumbling and cleaning after all, before plating I think. If you hire out the plating that would get another tumble/clean. I concur, DFM conversations with good people is always a joyful experience. For me, during 25 years of design engineering, those were some of the best conversations. Lot's of learning.)

Jacob Downing

Thank you Michael. I will do that.

Michael Bennett

The way the pins are currently designed, there's a slot for normal pinned blades (like coping saw blades) and also a thru-hole for a loose pin that will hold blades with a hole on the end (like a hacksaw blade). If you wanted to use bandsaw blades, you can drill a small hole on each end and use a loose pin to hold it in place.

Joel Hollingsworth

I've done some DFM work professionally, and it's always interesting. I'm excited for you as you work toward a product!

Jacob Downing

Is there a way to make pins that can hold a band saw (like the Paul Sellers video)? That way you could change out the blade when you swap out the handles.

Rex Krueger

I'm going to let John pick the alloy, but I didn't even know leaded was out there. Must be like "free machining" brass.

Rex Krueger

Unfortunately, carving away the material is still cheaper than multiple parts plus assembly.

Rex Krueger

Well, I did NOT know that! I can add text links in the future. No problem!

Jerry Moomaw

I did have to login to Patreon to see the video(or it seemed I did). It's something I too would rather not have to do. I rarely have a flawless experience here.

Daniel Hoover

I had this very thought, 1 steel tube for the saw connection, 1 steel tube for the threading and a washer with that electroconductive welding at the end. Glad it's sorted though.

Michael Bennett

I concur with the recommendation of 4140 for the material, especially if you can get leaded 4140. I ran many miles of it thru my father's screw machine back in the day. IIRC, it has about 0.2% lead added to the alloy, but that small amount makes a HUGE difference in the machinability. If you get hexagonal stock, you can remove the step of having to mill flats for the wrench.

Derek Geer

I am wondering if the "washer" could actually be a washer that slides down to a stop, shoulder or a cotter-type pin where you want it to stop. Then you aren't carving so much material.

Coby

1) this was *awesome*, thanks for sharing! I love seeing behind the scenes process 2) I don't know if it'd cause any problems, but including the link directly in the text of the post was really nice, because it meant I didn't have to log into patreon (which is kinda fussy sometimes...) to see the video (until I came to comment). If it isn't an issue, it'd be cool if youtube links were also included in the text of the notifications for all your early-viewing-video-notifications so that I never actually have to use patreon.

Boney Boards

Thanks for sharing. I like his suggestions it would make since to have the washer a little smaller as it is not as much waste bringing the pin down to the final dimensions compared to the washer. I have had success with threaded inserts. They make them out of stainless steel and brass. Brass would be to brittle for the constant motion this would be under. These are very common in mounting electronics to electric skateboards and the skateboards inserts are under a lot more stress and forces than what a saw would generate. This would one allow for straight threading for the pin going into the handle. I think the wood threads could cause the blade and handle not to be be as straight as it can be and effect the the cutting. The threaded rod could be put in the insert with thread lock either green or blue to be removable.

Howard Tuckey

That is a fascinating look into the process of designing any product, Rex! I'm not sure who the speaker is, but he does not even begin to sound the least bit bored or disinterested in/with what he does! It's just another example of why your Patreon and Youtube channels are so interesting and informative! You have a real talent for discovering and teaching things that we'd never really get to on our own. Thank you!

Jeremy Carlsten

Awesome, thanks for sharing!

Doug

This inside look is amazing, thanks for doing this and I cant wait for the kits to be available.

Rex Krueger

Unfortunately, as soon as you take it out of one machine and add an additional process, no matter how small, costs skyrocket. Keeping it in a single machine is very cost-effective.

Jim Williams

My Boss approves of your decision! He recommends 4140 for a wide range of parts.

Jeff Stauffer

That was fun to watch. I was just wondering, last night, how this project was coming along. Projects like this are fun to work through - I used to run a small manufacturing plant and this stuff was the most fun part of that job.

Bill Smithem

Interesting. Thanks for sharing this. :)

Daniel Tickle

After watching a lot of Wintergatan, the whole philosophy of designing specifically for manufacturer is an interesting subject. Thanks for the video!

Alex Lopatka

Thanks for sharing this look into the manufacturing process! Any more of these you can share with us as the process continues would be interesting, at least for me :)

Rex Krueger

And we're going with 4140!

Rex Krueger

A bunch of reasons: That would tie us to a machine thread on the shaft rather than a coarser thread for wood, it would mean buying or making a second part and then adding a step of assembly; surprising increase in cost. We're also moving the wrench flats up to the disc and there's no off-the-shelf part configured that way. So, it's great idea...until it collides with the realities of manufacturing.

Mark Diaz

Like Ethan Chitty, I suggested the threaded washer idea on the discourse site: https://rexkrueger.discourse.group/t/re-the-road-to-a-physical-product/6352/24 The wood threaded portion would have to be a bit less radius to allow the washer to get past those threads.

Jacob Downing

Some good feedback there.

Greg Preston

I really appreciate the share. This is especially interesting to me because my Dad was a tool maker for Brockway Glass in PA. When he retired he briefly had a secondary production shop in his garage where he would put final dimension and details on small pressed metal parts. It was fun learning and watching him figure out how to build the jigs needed to process the parts, sometimes numbering in the hundreds. In looking at your design and understanding what the finished product needs to be, I wonder if turning from a single piece is necessarily the only way to approach this project. Your workaround in the video could be tweeked to a very elegant solution by simply making the shaft in such a fashion as to add the (stop washer) upon instalation. Leaving a shoulder between the screw portion and the slotted shaft would produce significantly less waist in the turning and still provide a strong and stable component. Just my 2 cents.

Martin Hartley

Inspirational to see that you are collaborating with people who are passionate about their work and decide that it would be a "fun project."

Fred Wolsey

Looks like things are moving ahead. Free advise from an Engineer: Stainless is not a good choice. Its not as strong as alloy or carbin steel and has a myriad of problems if you don't NEED rust resistance. 4140 is an excellent material for tooling. I use it all the time. You need a radius between the washer and shaft on the blade side, about 1/16-3/32". Do you think the final product will be able to be shipped to Canada? (still trying to get a t-shirt)

Ethan Chitty

All indications are that you’ve got this sorted out. My one question would be rather than machining the entirety of the pin out of a single piece of bar stock, why not create a threaded rod and then have a thick threaded washer to create the retaining disc portion?