Budget alternative to fancy linear slide

I have been checking out nice 1D linear slides such as this and this and this.

Especially the first one is really nice since it has a built in encoder and a controller with RS232 interface. However, the downside is that these have a starting price around $1,700. The specs should be something like: • 100 mm travel • 1 mm precision • Encoder • RS232 / USB interface • Speed is not critical • The load will not be large (<5N) Does anyone have any suggestion how you could do this on a budget of say$500? Or does anyone have a suggestion for something completely different with the same function?

• Some of the possible key requirements you should consider are backlash (slop between thread engagement on one side or the other in a screw system), number of cycles (potentially an issue if you use tighter or polymer nuts to limit backlash), stiffness (particularly if you use a belt system instead of a screw), environment (dirt contamination) and consequences of positioning failure. Two pieces of round shafting and a screw driven by a stepper is pretty cheap, but not always the right answer. But then neither is a cast iron way, ballscrew, and brushless servo controller. – Chris Stratton Dec 13 '10 at 19:22
• what about footprint / formfactor? And quantities? Have you considered looking for a small local US shop to design one for you? – Dave Dec 14 '10 at 14:34

You could possibly salvage the mechanism from an old printer. The print head is normally carried using a toothed belt and small motor with some type of encoder feedback.

• Yeah, I thought about that too, but I figured it might be too much work.. Since I am not paying, I'm rather looking for someting "off the shelf". – Theodor Dec 13 '10 at 15:02

Take apart an old inkjet printer and use the slide that controls the printer head. Just remove the print head and install a plate.

A lot of the folks making 'open source' 3D printers are using this approach, you can probably even find some drivers for the stepper motors in particular models if you look around on their sites. There are several projects doing this so I'd just google "open source 3D printer" for more information.

If you want a more off the shelf solution, the MakerBot folks use a moving platform and i believe they sell the parts individually.

• Yeah, I checked out the MakerBot store, but unfortunately they are not selling the linear drive units as individual parts. Good suggestion though. And, yes, I am looking to find something that is as off the shelf as possible. – Theodor Dec 13 '10 at 15:06
• @theodor In that case i think your best bet is a used part from ebay or similar. – Mark Dec 13 '10 at 15:12
• @Theodor As a MakerBot owner and one that also uses high quality linear slides for work, I don't think want their mechanism anyway because there is a fair amount of roll and pitch. Although the resolution in the general direction of the axis is good (better than the 1mm you want), the amount of deflection under loads will be pretty unaccceptable. – Dave Dec 14 '10 at 14:29

1 mm precision (±0.5-mm) is not very precise for this type of tool. As you can see the linked examples are ±12-µm and ±15.29-µm.

This means you can go with something cheap: alibaba.com. I found this: Precision Motorized Translation Stages, from Beijing Shinhe Optical And Electrical Equipment Co., Ltd.. It looks like the DYT102 is the smallest that fits your requirements (100mm). They claim 8.12-µm resolution, 127-µm repeatability, and 15-kg maximum load.

It is $650: Tyler Lucas: Hello. How much is the DYT102 Motorized Translation Stage? (2010-12-13 13:34:51) Jason Zhang: the unit price of DYT102:$650/p, for your reference (2010-12-13 21:00:44)

• Well, thank you! I wonder if they have an european supplier? – Theodor Dec 13 '10 at 22:19
• @Theodor, I doubt they have a Euro supplier. The price is $650. – tyblu Dec 14 '10 at 5:05 • Thats pretty fair, given that it has similar specs to the$1700 Zaber slide. Cheers! – Theodor Dec 14 '10 at 8:53
• nice find! – Dave Dec 14 '10 at 14:30