Roto Casting parts

[asianflava]

I'm thinking about making a roto casting machine. I want to make it as simple as possible and as cheap as possible. A 2 motor 12V DC system with slip rings for the inner motor. Then cold casting with an epoxy type material.

I'm just in the initial phase of planning, just thinking about how I'll do it. I'm having a hard time finding a place for cheap motors, gears, timing belts, etc. I know that there are some home-brew CNC guys here and was wondering if they can direct me to some websites.

[PaulC]

I just Googled "roto casting forum" and came up with 10 pages! Lots of info on building them and parts. Wiki also has a page devoted to it.
Hope this helps you Mate.
Cheers
Paul

[BigAl]

Hi flava, I just saw this video of a rotocasting device made entirely from parts from a store like Home Depot and a Bicycle Parts Store.

This particular device is powered by one hand crank that you could connect to a single motor.

That motor is going to have to rotate slowly with lots of torque. So you need gears and/or a speed controller. Don't bother with stepper motors unless you have a need for that precision of control. Although they are just wonderful devices, they add a lot of complication to any project.

The first thing that pops into my mind is is to use an old electric screwdriver/drill as the drive motor.

Maybe you have one around that doesn't hold a charge any more that you could connect to a car battery? Pull the trigger with a small C-clamp or if you want to get really fancy replace the trigger with a potentiometer.

In my limited experience of bodging together CNC, robots, and other such flights of fantasy I always have a problem sourcing (for free) the correct bushing to mount my drive system to the motor I have available for the project. An old electric screwdriver doesn't have that issue, as you can mount a drive spindle of your own choice, directly into the chuck of the screwdriver.

eBay is also an excellent source of parts that are hard to find or hard to buy in non-industrial amounts.

Don't forget the old T&TTT mantra..... pictures please!!! :D

Look like a fun project, Good luck!

[Hillmann]

What size are the parts that you want to be able to make with it?

[Hillmann]

Windshield wiper motors work great for homemade projects like this, they are already geared way down, have lots of power (I know firsthand that ones from th 70's have enough power to really hurt you) have variable or multi speed and and when you shut them off they will continue until they reach there reset position so they always start and stop at the same position.

[asianflava]

What size are the parts that you want to be able to make with it?

I want to make a set of these:


They fit inside the body panel and were an option in Japan, never offered in the US. You can get a set on eBay, but they cost a pretty penny usually between $150 and $200 plus shipping from Japan. A few people have made them out of fiberglass, but I think rotocasting is a more viable option.

I found a motor on ebay with a gear reduction but I need 2 to make my simple version. If I can't find 2 slow speed motors, I'll probably have to make one like they show online.

I totally forgot about McMaster Carr. Looks like I can get the hardware there; bearing blocks, bevel gears, etc. I also found http://sdp-si.com/ which also has a nice selection.

[Hillmann]

What are they?

[Hillmann]

What are they?

[asianflava]

It's a speaker enclosure for a 20 yr old car. The speaker shown is 6.5in across so they aren't huge.

[BILLYL]

seems that your picture won't show - but I am interested in this.

I need to make a small radio cabinet and was wondering if this method could be used to make them?

keep us posted.

Thanks

Bill