The vertical spool holder I created for the RapMan spools worked very well. But, it was a pain to go from one color to another. Plus, I'd begun to experiment with various sources of filament and each of them seems to have a different spool type and size.
I needed a different solution. And, it seemed to me that a horizontal spool holder was my best bet for easy interchangeability. Here is what I came up with.
First the base unit.
The base unit is built so that it can be clamped to a table. There are recessed to take 3 bearings upon which the spools can rest. However, they are optional since a nut on the bolt or threaded rod can be used to support the bottom bearing of each spool.
It is designed to be a quick change system, allowing different spool hubs to be easily interchanged.
Here is the base and three different spool holders.
In this photo the base is at the left and is surrounded by 3 different spool hubs. Each hub has bearings pressed into the top and bottom. The bearings make for very smooth filament feed. And the small hook to the left, that attached to the bottom of the RapMan helps to feed the filament extremely smoothly.
Here is a close up of the filament guide. It's very simple. But, hugely effective.
I'm using commonly available 8mm x 22mm x 5mm skateboard bearings that cost about $10.00 per set of eight. Here is the drawing for the most unusual hub that fits an offset hub.
And, the largest hub for the system. The Spool for Bits and Bytes materials.
The system really works well and I will be putting up the STL files into free download sites.