[ehiebert]

I scavenged motors from printer this past summer and I am finally starting to build the mechanics of the machine.

My plan is to use 3/8"-16 allthread with these 80 oz./in. steppers. I am using Bosch (like 80/20) extrusions with UHMWV insets as the linear bearing material. The extrusions have a very small 0.8mm ridge on either side of the slot in which the inserts will ride which will reduce the surface contact area and frinction (I hope!).

The base frame is welded 2"x3"x0.250" steel and an aluminum moving gantry. I can get aluminum plate for $4/lb from a local surplus dealer, which is prenty spendy for scrap if you ask me.

Machine capacity will be about 36"x33"x5" or so. Yes, I know it will be very slow but I have way more time than money right now. This a home cookin' project ala Chuck Knight who inspired me to build one.

Here is a pic of the plan as of tonight. Let me know if I am starting off in the wrong direction here on the capacity and wimpy motors.

Eldon.

[Mr.Chips]

You can always add bigger motors later.
Hager

[JOE65]

Maybe you should span the bottom of your gantry with something so it can't splay outward.

[balsaman]

Spanning the bottom will be a must. Also for a place to hook the leadscrew nut.

Eric

[mvaughn]

Do you have a design for your z-axis yet?

Pics please.


I have found that by creating the base first and then creating the z-axis to fit is difficult. It really amazes me how much planned capacity I lose.

[mvaughn]

You say you got the steppers from some old printers. What were the printer models?

If they were Laserjet I, II, or III's, they are supposedly 100oz motors (I could be wrong that is what I read here).

If there were another model printer it would benfit others to know what printers have worthy steppers.

[ehiebert]

You say you got the steppers from some old printers. What were the printer models?

If they were Laserjet I, II, or III's, they are supposedly 100oz motors (I could be wrong that is what I read here).

I got these from old Laserjet-II and DEC printers (which look identical to Laserjet-II's). And Yes..... they are supposedly 100 oz./in. but I am thinking conservatively.

The printers themselves were old behemoths. I kep the electronics assemblies from them as they have some good parts in there. I will re-use the power supply modules and the driver circuitry to reduce cost.

Do you have a design for your z-axis yet?

Pics please.

I have no "pics" of the Z-axis yet. However I will post them as I create.

I also would like to dump my entire plans into the FTP site when finished. I am going to put them there with the objective that people can use them to build more machines, and also place their plans in the archives. There really is no need for every user to start from scratch on these things as many have already been designed and tested.

Spanning the bottom will be a must. Also for a place to hook the leadscrew nut.

Eric

Yes... I will turn the extrusin rail inward to account for a drive crossbar. What can I say... it was 2:00 AM

[radio-op]

If you didn't know, McMaster-Carr carriers a linear motion system very close to your design. It may be worth a look, give you ideas on the bearings for the rails.
Looking forward to seeing more!
Bill

[DDM]

Check out 8020.net, they already have extrusions for the linear slide system that you are planning on using. For the machine I plan on building in the future I'm thinking of using Teflon (PTFE) with bronze put into it instead of UHMWV. Check out Modernplastics.com. Just a thought

[ehiebert]

If you didn't know, McMaster-Carr carriers a linear motion system very close to your design. It may be worth a look, give you ideas on the bearings for the rails.
Looking forward to seeing more!

I am using the Bosch stuff because I already have it. I am using UHMWV because I already have it. And I'm using the 2x3 steel chassis because I have that scrap laying around also.

I will look at Mcmaster though for their slides.... just because. Thanks for pointing that out.

I use UHMWV for faces of table saw fences and WW'ing jigs. Its good stuff that I am familiar with. I am willing to put of with a little flex from the softer material. I am not building a laser drill here :-)

Eldon.