Question about casting

[Bill Weiler]

I wanted to make more Nanosumo robots but I need wheels. The 3D printer at Techshop can't make the 0.5mm features. I thought I would try casting. Before I do, does anyone know if it works for features that small, and is it cost effective? The wheel is 11mm in diameter and 4.1mm deep.

Bill W.

[Dave Curtis]

I've done a little resin casting. 0.5mm features are OK in some circumstances. Talk to me tonight about what you want to do. You will need to learn to get a good pour without bubbles.

-dave

On Apr 24, 2013, at 2:50 PM, Bill Weiler wrote:

> I wanted to make more Nanosumo robots but I need wheels. The 3D printer at Techshop can't make the 0.5mm features. I thought I would try casting. Before I do, does anyone know if it works for features that small, and is it cost effective? The wheel is 11mm in diameter and 4.1mm deep.
>
> Bill W.
>
>

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[Preston Monroe]

Casting can re-create super small details so half a millimeter will be no problem. As for cost efficiency I can't Speak on that compared to 3-D printing.

Sent from my iPhone

On Apr 24, 2013, at 2:50 PM, Bill Weiler <bill...@gmail.com> wrote:

I wanted to make more Nanosumo robots but I need wheels. The 3D printer at Techshop can't make the 0.5mm features. I thought I would try casting. Before I do, does anyone know if it works for features that small, and is it cost effective? The wheel is 11mm in diameter and 4.1mm deep.

Bill W.

[Butokim]

Bill,

 

 

You might want to take a look at Alumilite.  You can cast with tremendous detail with this stuff.

 

http://www.alumilite.com/Applications/Hobby.cfm

 

James M. Geidl, K6JMG
D.B. Cooper, you have  a message.
 

---

From: hbrob...@googlegroups.com [mailto:hbrob...@googlegroups.com] On Behalf Of Bill Weiler
Sent: Wednesday, April 24, 2013 2:51 PM
To: hbrob...@googlegroups.com
Subject: [HBRobotics] Question about casting

[James Nugen]

You might want to check out this site:

"Guerrilla guide to CNC machining, mold making, and resin casting"

http://lcamtuf.coredump.cx/gcnc/

-James Nugen

On Wed, Apr 24, 2013 at 2:50 PM, Bill Weiler <bill...@gmail.com> wrote:

I wanted to make more Nanosumo robots but I need wheels. The 3D printer at Techshop can't make the 0.5mm features. I thought I would try casting. Before I do, does anyone know if it works for features that small, and is it cost effective? The wheel is 11mm in diameter and 4.1mm deep.

Bill W.

[Dave Curtis]

MicroMark has casting supplies. Not necessarily the cheapest, but good variety.

http://www.micromark.com/complete-resin-casting-starter-set,8174.html

Also a good source for very small screws, small tools, etc.

-dave

On Apr 24, 2013, at 2:50 PM, Bill Weiler wrote:

> I wanted to make more Nanosumo robots but I need wheels. The 3D printer at Techshop can't make the 0.5mm features. I thought I would try casting. Before I do, does anyone know if it works for features that small, and is it cost effective? The wheel is 11mm in diameter and 4.1mm deep.
>
> Bill W.
>
>

[robotMaker]

The 11 mm diameter that you want to make is close to 7/16" diameter. It could be a wooden (or plastic) dowel, and cut the wheels to your desired thickness. You're in No. CA and I use to live in the area, and there are so many resources there that you can use. I use to get my casting supplies from TAP plastics. There was nothing to order just drive there and get the supplies needed. I now live in Austin TX and those places do not exist here and I have to order everything, which I avoid. There is no OSH here, which was the best place to get parts for my bots.

If you must cast your parts and keep it clean and cheap, I would recommend getting your mold making supplies and casting resins from a hobby shop.  My son uses a mold making putty that's clean and easy to use, it's called Easy Mold (easy mold silicone putty), you can see it on youtube.com. When I use it I prepare my master and everything first, then mix the putty and press it on to my part. It's ready to use in less than an hour.  I cast gears and pulleys with this. But mostly I use Silicone Caulking, from the local HomeDepot. I treat it with dishwashing soap and warm water to get it to be friendly act the same as the Easy Mold.

For a casting resin I avoid the usual casting resins for casting, and instead I use something like Envirotex Lite resin, it's clean and easy to work with, it's a one to one ratio mix. Or I will most often use Epoxy Resin, they come in various time curing times, from 5 Minutes to an hour, I usually use the 20 Minute, it's ready to demold and use in about an hour. It's a good time for curing and letting the air bubbles rise and it also picks up the same detail as Alumilite and it's cheaper.

If you do find a better way to make the wheels please let us know.

Cesar

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From: Bill Weiler <bill...@gmail.com>
To: hbrob...@googlegroups.com
Sent: Wednesday, April 24, 2013 4:50 PM

Subject: [HBRobotics] Question about casting

I wanted to make more Nanosumo robots but I need wheels. The 3D printer at Techshop can't make the 0.5mm features. I thought I would try casting. Before I do, does anyone know if it works for features that small, and is it cost effective? The wheel is 11mm in diameter and 4.1mm deep.

Bill W.