3D Printed Balsa Tools

[Joker 53150]

As 3D printers keep coming down in price, more and more hobbyists are buying them. After looking through some of the offerings on Thingiverse I found a number of different tools that looked promising for working with balsa. I think it would be useful for the community to put together a list of designs we've printed and tested, and will start with my favorite, a Balsa Stripper.

https://www.thingiverse.com/thing:1892640

Can a 3D printed version be better than a commercially available product?

Instead of simply printing and testing the product, I'm going to compare it against the "gold standard" of balsa strippers, the Master Airscrew Balsa Stripper. I've owned one of these for years, and it works very well. Plus, it's cheap and uses standard #11 blades. My only (minimal) complaints about it are that it's a little awkward to hold with big hands and that the adjusting dial is easy to bump and change the setting. With minimal care these little issues are easy to avoid and this tool makes the task of cutting strips of balsa from a larger sheet a breeze. In the pics you'll notice I've got two blades mounted in the tool. Well, most of two blades... I broke the tip off an old blade and mounted it with the good blade to help stiffen the cutting blade so it doesn't wander and follow the balsa grain as much. It can cut fairly thick balsa (in a couple passes) and this was an issue. Thin balsa doesn't seem to have that problem.








Now it's time to compare against the 3D printed balsa stripper.

First, the good points. It prints well and gives you two options for the bolts - either use wingnuts or the knurled pieces I used. It's much wider, and more stable as well. Adjustments are very secure and it's not likely you're going to accidentally change the setting. You could also run a couple screws down through it and use it as a bench-mounted tool if you cut a lot of strips.

Now, the bad points. Adjusting the cutting width is a little fiddly. It also doesn't handle sheets as thick as the Master Airscrew product, but it'll still do just about any thickness sheet I need. Those are the ONLY complaints I've got on it so far!








With a side-by-side pic you can see the size difference between the tools. I find the 3D printed version easier to use, but for a quick one or two cuts I'll still grab the Master Airscrew stripper for the quick adjustments.

 

[Joker 53150]

I've been a big fan of the Master Airscrew Razor Plane for years. Like their Balsa Stripper it's inexpensive and very effective. Can a 3D printed version compete?

First, a tour of the original. Notice it's got one screw to hold the blade and the blade cover down securely, plus two more screws to fine-tune the cutting depth on each side of the blade. It uses a proprietary blade sold by Master Airscrew (and others), not razor blades. My only issue with the design is that there is no real grip on the sides and it can be a little slippery. I guess some stick-on sand paper would solve that problem...! Once it's set up it just keeps working without any adjustments.





I found a similar version of Thingiverse, https://www.thingiverse.com/thing:1941030 , and decided to give it a shot. The design looked good, but I couldn't tell if it uses razor blades or the original blade from the Master Airscrew product. After printing and testing I found it works with the original Master Airscrew blades, but to make them fit you need to do a little trimming where the blade exits the bottom of the plane. A regular razor blade is way too narrow to work properly, although it looks like it would work in a pinch.

So I took the blade out of my Master Airscrew plane and set it up in the 3D printed version. Getting the right cut depth set was pretty tricky, as the blade holder and blade want to move as you tighten the screw down. In action I ran into more problems, as the blade would catch and twist in the holder, causing it to cut even deeper into the wood. The single screw wasn't enough to stop this from happening, and quite honestly it just wasn't worth the effort trying to make it work further, so I threw it all away as a failed experiment. I'd say stick with the original from Master Airscrew, although I'm still looking for another design that works even better!

 

[willsonman]

Informative!

 

[Joker 53150]

Informative!

Don't get used to it, I had a brief moment of clarity.

 

[Joker 53150]

How about a new handle for X-acto blades? There are a lot of options on Thingiverse, some better than others. The first one I printed was the "Inexacto Hobby Knife", which is similar to the regular pencil-size X-acto handle. It worked, but the weak point is where the blade holder screwed into the handle. For light work it wouldn't be an issue, but it just didn't hold up for me and I printed it twice at different fill rates to see if I could get better results. No such luck, I looked elsewhere for a stronger design and tossed these pieces away.

The next one I tried, FOUND HERE, certainly looked stronger, as there was much more material surrounding the blade. The design allowed you to use it with or without the handle. Without the handle you simply have a stout barrel shape (in red below) around the blade. Before committing to printing the entire thing I printed the main blade holder first, and later did the handle. There is also a blade cover which I also printed, but it didn't stay on very well so I tossed it.

The main blade holder is made from two parts that twist together. The design also has some recesses and bumps to give you better grip. I found the threads super tight so I had to work it on & off a bunch of times to get it to wear-in a bit. Now it's just about perfect, and the extra handle I printed (in dark gray) & glued on makes the entire knife easier to work with and more stable. This is a design that I'd print again.

 

[rockyboy]

I like this thread! Thank you Joker!

 

[Joker 53150]

I'm glad you like it, hopefully it helps people find tools that work and avoid ones that don't!

Speaking of tools that work, I found another balsa plane to try, HERE is the link. I wasn't too optimistic on this one, as again it uses only one screw to hold the blade, but this time it's a standard razor blade. As with the other plane, getting the blade even left & right is important and not too easy to do. My first cuts with it were way too deep, so I backed the blade back a bit and tried again. Surprisingly, it works pretty well! I won't expect the blade to last as long as the Master Airscrew blade, but a standard razor blade is certainly cheaper and this allows somebody who doesn't do much balsa work to try the tool out cheaply.

I think what I'll do with this one is set the blade very shallow, and use it for fine-tuning before I break out the sandpaper. This one will also NOT replace my original Master Airscrew razor plane, but I'm still looking!

 

[Joker 53150]

I've got more yellow PLA filament just begging to be used up, so the printer has been going much of the day just churning out various tools. Next up are a couple sanding blocks, found HERE. These are actually customizable, so you can pick the style, length, height, and width. For the first two pieces I went with a stock size (the smaller block) and for the other I increased the size by about 2.5x original size. I wanted to see how well they worked before getting crazy on different styles and sizes.

It looks like they'll both work pretty well, although I think I'll get more use out of the smaller block since I already have sanding bars closer to the bigger block's size. However, I'll still end up making a couple custom larger pieces that will better fit in tight areas. It remains to be seen how well the printed bolts hold everything together, or if they start to come loose during use - time will tell, but for now they look promising.

Also note, to help make sure the paper is gripped well by the hold-down plate I folded it once or twice before installing the plate and bolts. That makes the paper thicker and gives you the grit on both sides, which should hopefully help.

My tentative plan is to find a design or two that work well, and then print a few of each in different colors, and then use different grits in each. Yellow = 220 grit, blue = 180, etc.

 

[SlingShot]

My dad had a razor plane that looked like this one. It was loaded with double edge "blue blades". I shaved a little balsa with it. It makes you feel like you are a craftsman when the shavings started coming off.

 

[YooperJon]

I don't have a 3D printer, but I would like a balsa stripper and I need one too! Any idea how I may obtain a "printed " one?

 

[Joker 53150]

I don't have a 3D printer, but I would like a balsa stripper and I need one too! Any idea how I may obtain a "printed " one?

$8.39 for an original Master Airscrew stripper from Tower Hobbies, and cheap shipping is hard to beat if you don't have access to a 3D printer. Or maybe a local friend with a printer can make one for you, the design is available for free.

 

[willsonman]

So for the needs of my current project I decided I needed a planer so I tried this one. It uses three screws. I did not have screws short enough that had a head to support the blade on the back end but a couple of washers solved that. I found that using these two screws is important to set first and then secure it with the center screw. I'm able to plane hard and soft balsa with ease and just a few tweaking. I'll let the pictures speak for themselves.

 

[Joker 53150]

Nice find, not sure how I didn't catch that one on Thingiverse when looking for them... That design fixes the only issue I found with the last one I printed, by incorporating the two additional screws to keep the blade depth secure. On the original Thingiverse page it also shows a big washer/brace through the main razor blade mounting hole. Again, a good idea as it'll work well to keep the blade as flat as possible, another change I'll make with mine.

 

[roversgonemad]

That is a good looking little planer! I think I'll print one of those.

 

[rockyboy]

Nice find! I was about to order in the Master Airscrew one, but will run a print of this tonight instead!

Thanks Josh!

 

[Joker 53150]

Nice find! I was about to order in the Master Airscrew one, but will run a print of this tonight instead!

Thanks Josh!

Of the 3 designs I've seen, this is the only one that looks like it has the potential to replace the Master Airscrew planer. It'll be interesting to see how long a regular razor blade lasts compared to the Master Airscrew blades, as the MA ones last way longer than you'd expect them to. One advantage the printed version has over the original from MA is that there is no "keeper" or brace on top of the blade. I've had issues with the wood shavings getting caught between the blade and that brace, effectively clogging the tool.

 

[willsonman]

Yeah, I'm curious about that too. I've not been able to use it just yet other than for testing but those blades are stupid cheap and I have a whole box of them laying around anyway.

I'm on the lookout for a CG machine. This one looks ok to make by myself but I would prefer to not have that point but a swiveling pad to spread the load out for heavier models. I may just have to design one myself.

 

[Joker 53150]

The base and general design of that CG machine is solid, but you're right about the point being a problem. If that area of the design was re-drawn in a design similar to a teeter-totter, with a simple pivot at the top and a wider piece to set the plane on it would be a big improvement. I've got one from Great Planes (I think?), but the issue with it is that the pieces the plane rests on aren't secured to the vertical posts, so as soon as you take the plane off those rests fall off the posts. It works, but is a pain to use. I'd love to see one that could handle a 1/4 scale plane without risk of putting a hole in the wing!

 

[rockyboy]

I've been having great luck with a Vanessa Balancing Rig ala this thread & design;

http://www.rcuniverse.com/forum/tips-techniques-180/708060-vanessa-c-g-rig-how.html

http://creswellrcflyers.org/Text/Vanessa_CG_Machine.pdf

Sure it looks like my airplane is 'in traction' hanging from strings - but it works really well.

 

[willsonman]

Vanessa rigs are great and are one step short of the "big guns." The Xicoy CG meter is fantastic but OMG expensive.