New Project Idea: 3D Print a Brush Handle!

[peterno3]

I saw some great deals on silver badger hair knots over at Whipped Dog, and wanted to try to make a handle. I haven't used a lathe in a while, so I wasnt sure how good of I job I would be able to do, but then I remembered that I have access to a 3D printer through my University! For those of you who aren't familiar with 3D printers, they work essentially like an inkjet printer, but instead of ink they put down ABS plastic (the stuff legos are made of), and instead of just doing one pass they do hundreds to thousands. This allows them to build almost anything in 3D, 1 layer at a time. Using a brush I currently have as a model, I built a handle on my computer.



The only thing I have left to consider before I can print it is the hole for the knot to fit into. Since the hole is being printed and not crafted, I need to get it as close as possible to the right size from the start; I can't just craft it to fit. I guess I could try to drill it out, or widen it with a knife after the fact, but it would look nicer if it was printed correctly. I was wondering, how precise are the knot sizes? If I get a 22mm knot, how close will it actually be? Would I be safe making a 23mm hole for it to fit into, or do I want to try to get it tighter? I'm guessing the best way to go would be to buy the knot first, and fit the hole to it, right? Also, how deep is generally good for the hole? Any input is always appreciated!

 

[taco8slo]

Looks interesting, wonder how well the epoxy will hold the knot in the ABS, if it works out then that will be awesome to make whatever style you like. What color does it come out as, black?

 

[peterno3]

I know there are certain epoxies that work well with ABS, although I'm not sure if they all do (is there a standard epoxy used for brushes, or is whatever fine as long as it doesn't need a lot of UV or air to dry?). In any case, things that are 3D printed are generally not smooth, they have tiny grooves (only about 0.005 inches thick I think) from where each layer was put down. Hopefully the epoxy will seep into these grooves, giving it some extra stength.

Im actually trying to look into the color of the plastic now. I know they have a wide variety of colors (I've seen stuff in red, various colors of gray, and white), but I need to find out what my school actually has, and if I get to choose the color, or if I just get whatever is in the machine at the time. If I got to choose though, I'd probably go with either black or a blue color

 

[LarryAndro]

I ordered some resin handles some time back, and they had a slick texture. I was worried about the Loctite epoxy I used to glue knots into handles. So, I placed some glue to the outside of a handle, and let it dry. It melted into the resin before bonding, which gave it a lot of strength. I couldn't peel the glue off without ripping off some of the resin also.

When you glue PVC plastic pipe together, you use a solution that softens first, followed by the glue which similarly seems to melt the PVC plastic together.

But, lego plastic? I just now glued a badger hair knot on top of a Lego. (Don't tell my wife, or the kids the visit.) An interesting experiement...

 

[StuMcB]

Techno-knot

 

[taco8slo]

Whether it works or not it is definitely worth a shot, and it is relatively inexpensive too.

 

[LarryAndro]

I have been reading about 3D printers now for some years, and am very interested. Their prices are definitely coming down. Wired magazine recently said something about entry level prices are approaching $1000 (as I recall.)

Here's the Wikipedia article...

http://en.wikipedia.org/wiki/3D_printing

 

[hig789]

Very interesting. We had one of these in my machine shop class at vocational school. They got it as I was graduating so I didn't get to use it but I have seen some of the stuff you can make on one and it seems pretty amazing. Can't wait to see it done.

 

[peterno3]

Thanks everyone for the interest! I'm going to be using a 22mm knot, which is being provided by whippeddog.com (thanks!). Is there a way to figure out what depth the hole for the knot should be? I've been searching online, and i've found that it depends on the desired loft, but haven't found an actual recommended depth. I'd prefer to be able to print it to the perfect size, but I could always drill it deeper/add some pennies if i need to.

 

[hig789]

Usual range is 45-50mm based on your preference. I have been setting mine at 48mm it seems to be a good all around loft.

 

[MeanGene]

One of my buddies is an artist and he has one, a 3D printer, in his art gallery. Him and the artists there make cool stuff with it. The most joy they have, also being computer geeks, is creating spare parts for the printer in the event one of them breaks. They are awesome. That would be so much fun to create handles, print them, rinse and repeat. I can't wait to see your progress.

 

[peterno3]

I finished modeling the handle and submitted it for printing. Theres unfortunately a bit of a queue already though, so it may take some time. I don't know if this means days or weeks, but I'm going to try to check back in next week to find out

 

[Neep]

Thanks everyone for the interest! I'm going to be using a 22mm knot, which is being provided by whippeddog.com (thanks!). Is there a way to figure out what depth the hole for the knot should be? I've been searching online, and i've found that it depends on the desired loft, but haven't found an actual recommended depth. I'd prefer to be able to print it to the perfect size, but I could always drill it deeper/add some pennies if i need to.

OK... folks are saying to set the loft of your 22mm knot at 45mm to 50mm.
I am going to show you that there is a problem.

#1 rule : Always make the hole for the knot size and loft that you want to end up with.
In other words, start with the particular knot you are using, and make the hole fit IT

#2 rule: All 22mm knots are different. Which is why we obey rule #1

I am going to provide you with an illustration.
Here we have two "22mm" brush knots. (from different sources)
Both have the same total height (66mm), both have the same plug depth (8mm).

One (A) has a plug diameter of 22.5mm - that isn't going to even fit into your 22mm bored hole in the handle
The other (B) has a plug diameter of 21.5mm - that will fit into your 22mm bored hole.

BUT
(see, that is a very big BUT, and its in red too)

If you want to end up with a loft of 50mm, then your hole needs to be 16mm deep.
And THAT is where you will run into trouble.

I measured the diameter of those two knots at the 16mm depth, with the hairs squashed in the digital calipers as tight as they would go.
In other words.... the diameter that your hole would need to be.

Brush A: 25mm
Brush B: 22.9mm (let's say 23mm)

Now, the total height of your 22mm knot may be different. But the same principles apply!

The only solution.... see rule #1 above.

Cheers
Rod

Edit: A stepped and tapered hole overcomes this problem.

 

[Shmu]

Edit: Accidentally drilling the hole bigger than you meant to overcomes this problem.

FTFY

 

[peterno3]

Great, thanks for the information Neep. My time with the 3D printer is unfortunately limited, so I had to submit it before my brush actually showed up. I also have access to a drill press though, so I can always adjust the hole after the fact. 3D printed holes aren't perfectly round anyways, so it might be for the best anyways

 

[peterno3]

The handle finished printing this morning! It ended up printing in white which wouldn't have been my first choice, but its not too bad. I'm just waiting on the knot, which should hopefully be in in a couple days

 

[Neep]

Cool concept
How hard is the material?
Will it polish up?

Cheers
Rod

 

[MeanGene]

Sweet! That was much faster than expected. Can't wait to see it with a knot.

 

[mblakele]

I kind of like the micro-knurled look from the printed material. It looks grippy.

What printer hardware did you use?

 

[peterno3]

It's actually quite hard. It prints with high density ABS plastic I believe, which is Lego plastic but much harder. It would probably take a little more work than polishing, probably either some sanding or possibly melting it somehow. As mblakele mentioned though, the ridges actually make it nice and grippy. If it were smooth, it could get kind of slippery when soapy and wet. One of my friends suggested coating it in PlastiDip, but I don't know if i want to cover it up

I don't know the exact model number, but its one of the newer Dimension printers. Its a pretty fancy industrial one which is nice