Reply with QuoteOn the side of the tube are the linear rails. THK RSR12 linear bearings bolted to a 3/4 x 1/2" cold rolled flat which will be welded to the side of the tube.
My first Router / Plasma Table Buildup...
Hey Guys.
Been checking out your router tables for a few weeks now and decided to finally start building mine. I will mostly be using it for Plasma Cutting steel plate. I'll be making various tool plates for the Z axis if I want to mount a router or other tools to it.
The basic frame layout. 1.5" x 3" x .125 steel tubing.
Working area about 30" x 54" x 5"
Here's a few pics.
Similar Threads:
On the side of the tube are the linear rails. THK RSR12 linear bearings bolted to a 3/4 x 1/2" cold rolled flat which will be welded to the side of the tube.
A lot of holes to drill and tap...19 on each rail x 4 rails.
Here is one side nearly completed. I am going to use two motors for this axis. One on each side of the gantry.
Some specs:
Vextra 440 in oz steppers
Gecko drives G201
Radio Shack 30V 1000ma power supply
Nook 1/2" x 10 5 start (2 pitch) leadscrew
Delrin "home made" nuts
So far I got 374 IPM running a 800mhz PIII with MachII
I think I'll need to upgrade my computer to go faster...
Home-made Acme Tap
Close up of left side of gantry plate showing linear bearings and lead screw nut.
Keep in mind that I usually build without plansSo, if it looks alittle crude...
Nice bearings and great speed. I was wondering how did you mount the support for the motors? It looks aluminum but I saw the tackweld on the side. What size is it? I enjoyed your pictures and looking forward to more. Nice work, keep it up. chris
Cool router so far! You radio shack PS might be a little light. That's only 1 amp. What are your motors rated at?
Eric
I wish it wouldn't crash.
pach rat:
The mounts for the motors are alum. and are bolted to 1/2" steel drilled and tapped plates that are welded to the corners of the frame.
balsaman:
--BTW, I enjoyed reading your buildups, nice job on your router(s)---
Yeh, so far the 1 amp has been doing the trick. But your right, I probably will have to upgrade. I may wire two 30v tranformers together in series to get 60volts and 1 amp. I need speed more than torque since I am only dragging a torch and not a pushing a router for now.
looking at your pictures reminds me of a question i have been meaning to post.
Has anyone had any success/problems with mounting the lead screw on one side of the machine? I have been planning on putting mine underneath in the middle (x axis). I would like to mount it on one side like your picture but am worried about that possibly cocking the gantry as it moves. Doing it this way would save me the trouble of having to raise the table but it seems like pulling on one side would through off the movement. Am I nuts?
I believe he is using two lead screws for the axis.
InventIt,
If you want to use transformers, you will need to rectify it and filter it. The DC that comes out is around 1.4 times the ac voltage. Two 24 volt transformers gives you 48 volts, rectified you will get ~70 volts DC. Perhaps you mean two 30 v RS powersupplies..
What's the motor voltage and amps? I would think you need one RS powersupply for each motor...at least.
Eric
I wish it wouldn't crash.
avsfan733:
I am using 2 leadscrews for the reason you mentioned. I did run the gantry with just one motor/leadscrew hooked up. It tracks straight without any load but the unsupported end of the gantry is very weak. It could not support a router without flexing.
balsaman:
Sorry to confuse you. I did mean two RS power adapters 30V each tied in series to give 60v.
Motors Specs:
PK296-4.5
440 Oz In
2.8 Volt
3.18Amp/Phase
Motor Performance Chart
More Specs
Rob
You will need a 10 amp supply at least I would think.
Eric
I wish it wouldn't crash.
Nice home made Acme tap. Can you show me how? i don't really want to pay $50 for a tap.
It looks like you just used the leadscew and cut it right?
Last edited by ezland00; 12-03-2003 at 08:19 PM.
Update...
Got the right side lead screw completed. Now I have one step motor/lead screw combination on each side (to prevent the gantry from skew). Did some testing and it's not looking goodProblem is, during rapid moves one stepper may miss steps or completely stop altogether. Well the other side just keeps on going and next thing you know the whole gantry is twisting and flexing. I did notice there was some binding in the lead screws and after loosing that up it did work better. It's just not working like I want it to. Actually worked better with just one lead screw/motor.
Looks like I'm going to have to re-design. I need to just use one stepper/lead screw. Somehow I’ll have to tie the two sides together. I'm thinking some kind of cable arraignment like on a drafting board or maybe I'll just go with timing belt drive
Any ideas???
Rob
Hi Rob,
If you use 2 leadscrews, and one motor mounted between them with two timing belts, one going to each leadscrew, then you would have identical motion on both sides of the gantry. Before re-designing mechanically, I would try using the rated current to the motors first. For 2 motors at 3.18A per phase the maximum current draw on your power supply would be 4.24A (plus the requirements of the other axis motors) using bi-polar step drivers.
Steve.
A question regarding your homemade thread tap and lead screws.
Have you run the machine long enough to have any heat build-up problems between the screws and nuts. I'm also making a homemade tap and noticed that there is a very close tolerance between the two,good for anti-back lash, but maybe not for the amount of friction.
ezland00: Yes I just used as piece of acme rod and ground a taper on the end with flutes for the chips.
Jan: Can't really say as of right now. I have not really ran the table except for some testing. I did notice some warmth on the screws after a few rapid moves. I think the friction on my machine is a misalignment problem rather than a close tolerance in the nut.
If you guys are having a problem with friction on the leadscrews use this product. Slip Plate dry graphite lube. I thin it with enamel reducer and paint it onto the leadscrew. Let it dry and run it in. The more you run it, the smoother it gets.
drilling holes
I am in the process of building my metal frame CNC. I am also using THK linear bearings. I have one question. How did you precisely drill all the holes for your linear bearings so that each hole is exactly evenly spaced? What sort of method did you use.
Thanks,
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