What is the Name of this Spur Gear Assembly - Page 1
Forum section: electronics / general

author: bostonman
author_rank: Super Contributor
timestamp: November 13, 2022, 04:01:44 pm
content: I have a project in mind that would require something similar in the attached. I could 3D print it (which is where I got the picture from), but I'd rather buy something more sturdy.Does anyone know the name of this setup so I can search for them?

author: jpanhalt
author_rank: Super Contributor
timestamp: November 13, 2022, 04:05:54 pm
content: Generically, it converts rotary motion to linear or visa versa. I would call it a rack and pinion drive/leveler/adjuster/etc. Older steering in cars was one common example. Too many applications to list.

author: bostonman
author_rank: Super Contributor
timestamp: November 13, 2022, 04:10:04 pm
content: I'll try searching for that.Makes sense, because you're correct, that is the same as rack and pinion in older car steering.Basically I want to do the same setup as in the picture, but want to try getting some high temp suction device to pull IC off boards should I use a hot air pencil.

author: jpanhalt
author_rank: Super Contributor
timestamp: November 13, 2022, 04:22:18 pm
content: Check out used microscopes for parts. You may find something with an X/Y rack and pinion stage + the up and down for very cheap.

author: Ian.M
author_rank: Super Contributor
timestamp: November 13, 2022, 04:28:09 pm
content: Even if you find something suitable, you won't be happy with it for a vertical axis moving anything of significant mass, without either a counterweight or a near constant force spring mechanism (e.g. a clockspring) to take most of the weight off the rack & pinion. As-is, I'd bet it has to have very high friction just to stay put, which you have to fight against for every upwards movement.

author: jpanhalt
author_rank: Super Contributor
timestamp: November 13, 2022, 05:07:00 pm
content: Since the TS is using vacuum to pull IC's off a board, the maximum lift force will the limited to atmospheric pressure at the location -- about 14.7 #/in^2 A 6mm square IC would be limited to less than 1#.That should not be terribly difficult to overcome with any rack and pinion and fitted gibs, particularly like the ones used in a microscope.

author: totalnoob
author_rank: Regular Contributor
timestamp: November 14, 2022, 12:58:11 pm
content: That is called a "rack and pinion". They are standard and you can buy them "raw" (i.e. I believe you can get it in different lengths and sizes and cut it down to the length you need) from industrial suppliers.I see that you're in the US, probably the cheapest option would be to buy a HF 1 Ton Press and strip it for parts, because buying rack stock is pretty expensive (see McMaster Carr's website). Alternatively, you might be able to find it less expensive on Ebay as a metal lathe feed rack and cut it to the size you need. Not sure what else you can look under to find it, on Ebay.But, as someone else pointed out, a different strategy may be better. Using an ACME threaded rod and nut (again, standard sized stocks are available from industrial suppliers) should make it easier for overcoming the pressure, although at the cost of taking additional time to move.

author: thm_w
author_rank: Super Contributor
timestamp: November 15, 2022, 12:49:41 am
content: Search for linear motion guide, you have various options:- ball screw- timing belt- threaded rod (mentioned above)But I can't see how its a suitable option really, unless its a VERY large IC.SDG did a review recently, might give some ideas:

author: Smokey
author_rank: Super Contributor
timestamp: November 15, 2022, 01:01:00 am
content: Quote from: thm_w on November 15, 2022, 12:49:41 am"How to suck off your ICs professionally..." ... heh ...Focus rack is, I think, what that rack and pinion on a microscope is usually called.

author: bostonman
author_rank: Super Contributor
timestamp: November 15, 2022, 01:56:02 am
content: I like that tripod, and, in fact, that looks like a better and cheaper solution than my idea.My only concern would be whether one (or a few) legs remain soldered, the vacuum may pull the IC chip and a pad will lift off the board as a result of pre-mature lifting.

author: Smokey
author_rank: Super Contributor
timestamp: November 15, 2022, 04:13:57 am
content: Quote from: bostonman on November 15, 2022, 01:56:02 amI have the hand piece vacuum picker on my hot air rework station. I've never pulled a pad off. I'm not sure it has enough suction. The part just doesn't stick if it's not ready to come up.

author: bostonman
author_rank: Super Contributor
timestamp: November 15, 2022, 04:36:18 pm
content: The more I thought about this, I realized maybe a way to mount either, a vacuum or a hot air pencil.When I went to solder a new chip, I needed my hands free to keep the IC in place and couldn’t keep the hot air steady.

author: thm_w
author_rank: Super Contributor
timestamp: November 15, 2022, 10:10:44 pm
content: Quote from: bostonman on November 15, 2022, 01:56:02 amThe spring is providing the force. Spring doesn't look too strong, but, you could design in a weaker one if needed.