[rwskinner]

I'm designing the slide for my ATC. I had planned on using two 20mm linear rods however for this application I'm wondering if I could get away with some 3/4" Polished Rod and run 4 carriers with bronze bushings.

The setup will be sort of like Tormach's with a small air cylinder sliding it back and forth with a positive stop on the spindle end. Total Rod length 18" with a 6" wide carriage for 12" of travel.

Opinions?

RIchard

[pete from TN]

How about instead of going thru the trouble and expense of fabbing up a linear rail or otherwise, why not make a simple and sturdy pivoting mount for it that secures to the column. If you make the mount real adjustable it would make for a simple alignment of the unit once it is in place.... Also if you engineer the pivoting mechanism carefully it will not be a large heavy weight hanging out the side of the machine and it could possibly swing in a specific arc that actually gets it out of the way of chips easier... Oh and by the way, I am JEALOUS as hell that you are to the point of making one for your machine. Being the modbus and electronics master you seem to be it will probably be a SWEET setup. I cannot wait to see an RF45 with a nice changer equipped. March on my freind...haha peace

Pete

[rwskinner]

Ah, rails and bearing blocks were not that expensive. I ordered some import 20mm rail and 4 bearing blocks, stepper and driver from KelingInc. I ordered the bearings to so I will have some stuff to do soon. 20mm seems a little over kill.

I'm using the bottom forks made of 1018 steel for engaging into the slots of the TTS Holders then some 1/8" thick plastic for the grippers.

That brings me to my next question, on the plastic, which kind should I get that machines okay and also is a little springy so they grip my holders?

They will be like a U shape but come around a little further so they snap around the body. All one piece.

Richard

[rwskinner]

I forgot the attachment....

[gd.marsh]

Richard,

I can't speak for the machining capabilities, but I would think Nylon would be a good material for wear resistance & springiness at the same time.

I'm with Pete, jealous to the max .. So we'll cheer you on as you pave the way for the rest of us heading in that direction.

Gary

[pete from TN]

I would make them from Delrin, due to it's wear resistance and lubrication qualities it should last a long time. Machined from that thickness it should be also pretty springy... If it was thicker it would be pretty stiff I would imagine. Nylon would be a second choice and should work fine as well. I am also interested in hearing about how you intend to machine the toolholders for the groove. My holders actually have a sort of groove in them but I seriously doubt it was the right shape or size, I am just not that lucky....peace

Pete

[dugpits]

That brings me to my next question, on the plastic, which kind should I get that machines okay and also is a little springy so they grip my holders?


Richard

Hmm... I think Nylon is a little flexible, and HDPE (polyethylene), and Teflon (PTFE) might work....but don't breath in any teflon fumes - not good for you.

Good luck - would love to see pics when you get it started, sounds like a fun project.

-Doug

[ninefinger]

Go for nylon if you want reliable flexing, even in a small amount. Delrin (acetal) can become brittle and fracture from flexing. Look at a model airplane propeller - many are made from glass filled nylon but in this application you won't need the glass fill. Flexible yet strong. I think you'll find that nylons wear resistance will be perfectly fine.

Teflon is too much $$$ for this application, use it where sliding is a primary concern.

HDPE - I'm not sure about this one - I don't have experience with it though i have some pieces I've never used... apparently it cuts like wood...

my 2 cents.

Mike

[hoss2006]

Nylon works great on mine for the grippers, hdpe didn't hold it's shape and wouldn't hold tight.
Hoss

[jid2]

Nylon or Delrin are excellent polymer spring materials, I usually use Delrin for anything that will see springing and sliding with other parts. But, Delrin is typically not as resistant to chemicals. So for this application I think Nylon is the best fit.

[rwskinner]

Thanks for all the input, Nylon it is. Anyone have recommended sources?

I got my little Pic micro controller board up and talking to Mach via Modbus RTU. 4 Ins, 4 outs, 8 analogs. It can handle from 3 volts to 32 volts so it's nice for directly driving relays and such. I *may* use it for the air cylinders and the permissive inputs on the ATC.

Richard

[jid2]

Mcmaster of course:

Nylon 6/12 would be a good choice: McMaster-Carr

[Starleper1]

Richard, good to see your moving right along. Nylon is a good choice for this application, should work great.

[endo47]

Richard, you might consider Kydex. It is very rigid even in thin dimensions, but should flex enough to allow the holders in.

KYDEX, LLC - Products

[rwskinner]

I did a few of the holders to see how well they machined. Once I got the feed and speed nailed they weren't *too* bad to cut.

Also, here is a pic of one of my Multi-IO cards I designed and built up.
I have several hundred of these running on natural gas compressors for a telemetry system so they are proven in very noisy environments. Up and talking with Mach via MB RTU. Probably my expansion card and ATC controller.

Features:
16 analogs 12 bits
1 frequency input
8 isolated digital inputs
8 digital outputs

Communicates with Raw USB HID, or Modbus RTU or ASCII over USB CDC, RS485 or RS232. The breakout board normally has a DC/DC converter but I sawed it off to reduce space.

Non related, but I added another saw to the shop. Enco 7x12 band saw. Cuts much faster than my old 5x7 HF.

[pete from TN]

Two words my friend.....KICK ASS!! Peace

Pete

[cjdavis618]

I did a few of the holders to see how well they machined. Once I got the feed and speed nailed they weren't *too* bad to cut.

Also, here is a pic of one of my Multi-IO cards I designed and built up.
I have several hundred of these running on natural gas compressors for a telemetry system so they are proven in very noisy environments. Up and talking with Mach via MB RTU. Probably my expansion card and ATC controller.

Features:
16 analogs 12 bits
1 frequency input
8 isolated digital inputs
8 digital outputs

Communicates with Raw USB HID, or Modbus RTU or ASCII over USB CDC, RS485 or RS232. The breakout board normally has a DC/DC converter but I sawed it off to reduce space.

Non related, but I added another saw to the shop. Enco 7x12 band saw. Cuts much faster than my old 5x7 HF.

Man that is awesome work.. Congrats on the saw too. Those are nice. I have a Grizzly 6x10 and it is great.

That is cool stuff you are working on..

[Starleper1]

We have the Vectrax version of that saw, and I have to say it's worth every penny. I've cut everything from plastic to stainless with that saw. Good choice, you won't be disappointed.

[jid2]

Nice - I have that same Enco saw, just a bit older and dirtier. Got it for $350 bucks from a guy I work with and it has been great so far.

[rwskinner]

I'm working on the gear ratios of the ATC. I was hoping to go direct drive but because of resolution, spacing requirements, and durability I decided to offset the stepper and use a belt/pulley system.

My Carousel is 10.540" OD (Centerline of the TTS Holders).
So 10.540 x Pi = 33.113" circumference.

Direct drive
Using a G201X with 10 microsteps = 2000 steps per revolution.
33.113" / 2000 = 0.01655" per step

I'm not sure how close I need to be with tapers on the top of the holders but I would guess at least within a few thousands?

With 4.1 pulley I can get within 0.004" and should be able to adjust my forks to account for the resolution difference.

Opinions, suggestions?

Richard