Saturn 2 4x4 - Nema 23

[difalkner]

I ditched the glass and business card shims but this is the only photo I have from when I installed my tramming plate and did the calibration. I recall that I ended up with about a 9" span or diameter for the dial indicator so it was sampling a fairly decent sized area.



David

[GME]

I forgot to mention something about tramming. Tram front to back first! For front to back, you need to shim behind the top or bottom of the tramming plate, (or behind the top or bottom of the router mount), depending on the direction indicated by the dial indicator. I went with, and recommend, shimming the tramming plate. Also, I used standard weight aluminum foil for shims. It's .0005" thick, half the thickness of my thinnest steel shim stock. Anyway, If you don't do fore and aft first, you risk messing up the right to left tram when you loosen the tram plate bolts. Less risk associated with front to back first.

I used plate glass for tramming, but only after I was satisfied my spoilboard surface was parallel with the gantry. I started out trying to shim the glass, but found that the slightest pressure on the glass would cause deflection, and sheets of paper, business cards and the like were too irregular to reliably use them. Also, the glass wanted to slide around and scatter shims when I tried to insert new oI found myself trying to chase shimmed flatness for a couple of hours before I figured out I wasn't going to get it. Then it hit me that even with slight ridges from out-of-tram surfacing, the plate glass would ride on top of the ridges evenly. All I had to do was ensure that the glass was clean and the spoilboard was free of dust - so the glass would lay flat. Sure. it's possible that there were small irregularities in the glass, but decided that the cost of marginally greater precision (precision ground granite slab) wasn't worth the cost and effort. Besides, MDF isn't ever going to be precision flat.

I stayed with the plate glass, because I couldn't rely on my dial indicator plunger to read consistently from either a ridge or a valley. Like David, I have a flat round plunger tip. I use mine to set jointer blades. However, with glass, I wanted the accuracy I thought (perhaps wrongly) a more pointed end would give. At the end of the day, my results were both acceptable (within .0005") and repeatable. (Note: .0005 is not entirely certain, because not all of my measuring devices are certified or even advertised accurate to that resolution.)

Gary

[PLJack]

I ditched the glass and business card shims but this is the only photo I have from when I installed my tramming plate and did the calibration. I recall that I ended up with about a 9" span or diameter for the dial indicator so it was sampling a fairly decent sized area.
David

I like that a lot better. I don't have that apparatus. I stewed on making an adapter for my dial mag stand arm. But I was in the mood to mill something.
Thought I would share this technique for milling small parts I used with my desktop machine is case anyone finds it useful.

First cut an outside profile of the object.



Leave enough at the bottom to pull the part out from the front. I believe this is called onion skinning.



Then with the same profile make a pocket on some scrap.



Insert the part into the pocket and face one side.



Flip it over, face and mill anything else. Hole in the case.
Pop it out and done.



I'm sure you all know this but I was videoing it anyway.
I've done this many times with all kinds of shapes. If it's not symmetrical just do two pockets in the same place but have one mirrored, if you need to face the back.

The hole is for my long 6mm bit and the slot is for the tab on the back dial indicator. I will need to drill a hole through the slot to secure the indicator with a bolt.
It's about 150mm long so I should be able to swing an 11" circle. That's about all the room I have to swing at the moment because the face is not fully surfaced.

BTW: With this job I forgot to set Z and plowed a non spinning bit into the redwood and had to hit EStop. Hate that sound. Guess that makes my machine officially up and running.

[ger21]

plowed a non spinning bit into the redwood

That sure looks like walnut... Or are you talking about something else?

Leave enough at the bottom to pull the part out from the front. I believe this is called onion skinning.

If you push the part out the back, there's less chance of the wood peeling off of your part.

[PLJack]

That sure looks like walnut... Or are you talking about something else?

It could be walnut. I's from a palet. I used to keep an eye on palets coming in at work. My understanding is that a good deal of the worlds hardwood is tied up in palets.
I even snagged an entire palet made of balsa wood! The whole thing weighed like 10 pounds. Balsa is **** to mill btw.
I stopped messing with palet wood when I realized I had no idea where it has been or what it was exposed to.

If you push the part out the back, there's less chance of the wood peeling off of your part.

Good advice.
Thanks.

[PLJack]

Trammed this morning. It was only off by 180 thou!!!




I got it down to 3 thou. About the best I can do with this tram bar. I'll make a new one, longer, when things settle down and tram it again.
I also saw about 15-20 thou on the Y axis. I have no adjustment for that. Will address next tram.

Good enough for another run though. This should be the last one for a while. I'll move on to working out a system for squaring the gantry and steps per calibration next.
Then cut the top board profile.

Thanks.

[ger21]

.003" in 12" is plenty close enough.

[PLJack]

.003" in 12" is plenty close enough.

Seems to be. I running the job now and the finish feels amazing.

Thanks Gerry.

Jack.

[ger21]

Our big router at work is off enough to feel a step with a 3" spoilboard bit, but it's not noticeable with any normal cutting.

[PLJack]

Trammed on the left. Not trammed on the right.




Finished. Came out great. Time for some more calibration.

[GME]

. Time for some more calibration.

Looks great. I like your tram arm. Nicely done.

I have a technique for setting steps per for the X and Y axes using 1 2 3 blocks and a dial indicator, if you're interested. Nothing very complicated, but the more blocks you have, the better. I used 12 blocks, which gave me a measurement distance of 33 inches. IMHO, it's more accurate than trying to read a scale. For my old eyes, I'd be lucky to get a measurement off a scale within .015" or .020".

Gary

[PLJack]

I have a technique for setting steps per for the X and Y axes using 1 2 3 blocks and a dial indicator, if you're interested. Nothing very complicated, but the more blocks you have, the better. I used 12 blocks, which gave me a measurement distance of 33 inches. IMHO, it's more accurate than trying to read a scale. For my old eyes, I'd be lucky to get a measurement off a scale within .015" or .020".
Gary

That sounds interesting. Although I only have 3 123 blocks. This time around I tried something different.
I measured my ruler with calipers and saw the the final length is just to the end of the black mark.
I cut a notch in a dowel and put it in the spindle. Moved the it past the ruler and then forward to remove backlash.
Snugged it up against the ruler. Moved Z up to clear.




Set X to zero and ran a GCode command to move it 900mm.



You can see it was a little shy.

Change steps per accordingly. Rinse and repeat until it lands at the end of the black mark.
Seemed easier to read to me than a pointy stick.

Thanks.

[PLJack]

I was seconded guessing myself when spending all that time milling so many holes in the board. But those bolts just keep paying off.
I wanted to face the entire face of some wood. I seem to do the a lot and clamping was really hard on my other machine.

Took me about 20 minutes to make a jig.

Clamp anywhere to get started.



Screw down parts and move clamps and cut again.




Done. Worked out great.



mmmmm, so smooth.

[GME]

Originally Posted by GME
I have a technique for setting steps per for the X and Y axes using 1 2 3 blocks and a dial indicator, if you're interested. Nothing very complicated, but the more blocks you have, the better. I used 12 blocks, which gave me a measurement distance of 33 inches. IMHO, it's more accurate than trying to read a scale. For my old eyes, I'd be lucky to get a measurement off a scale within .015" or .020".
Gary

That sounds interesting. Although I only have 3 123 blocks.

Here is a drawing of the setup:




Lay out the 1 2 3 blocks as indicated for either X or Y. Clamp, or otherwise fix your dial indicator to your router. Zero where indicated. Command a move the distance represented by the number of blocks used. Read the distance moved by taking the distance represented by the blocks and either add or subtract the observe whether the dial indicator gives a + or - or zero. If zero, steps are right on. If a positive number, your move was longer than commanded by the amount of the dial indicator's reading. If negative, the commanded distance is short by the amount the indicator reads. Once you have a reading, reset steps and repeat until you have it set perfectly.

If you use this method, I suggest you measure the 3" length of each block, or better still, put 2 together and measure the 6" length. For most of mine, I went on the cheap side when I bought them. There off by + or - .0005 to .002. I measured them in pairs and added up the true total distance of travel.

Gary

[GME]

Originally Posted by GME
I have a technique for setting steps per for the X and Y axes using 1 2 3 blocks and a dial indicator, if you're interested. Nothing very complicated, but the more blocks you have, the better. I used 12 blocks, which gave me a measurement distance of 33 inches. IMHO, it's more accurate than trying to read a scale. For my old eyes, I'd be lucky to get a measurement off a scale within .015" or .020".
Gary

That sounds interesting. Although I only have 3 123 blocks.

Here is a drawing of the setup:




Lay out the 1 2 3 blocks as indicated for either X or Y. Clamp, or otherwise fix your dial indicator to your router. Zero where indicated. Command a move the distance represented by the number of blocks used. Read the distance moved by taking the distance represented by the blocks and either add or subtract the observe whether the dial indicator gives a + or - or zero. If zero, steps are right on. If a positive number, your move was longer than commanded by the amount of the dial indicator's reading. If negative, the commanded distance is short by the amount the indicator reads. Once you have a reading, reset steps and repeat until you have it set perfectly.

If you use this method, I suggest you measure the 3" length of each block, or better still, put 2 together and measure the 6" length. For most of mine, I went on the cheap side when I bought them. There off by + or - .0005 to .002. I measured them in pairs and added up the true total distance of travel.

Gary

[wmgeorge]

Or like I do with my system of T tracks and clamps. Put your work anyplace on the table, it just needs to be square and I can take that off the tracks. All my jobs, origin is Center. Use my Pendant to goto the center of the work, Zero it all out raise the Z and hit Start.

Pictures from my Bear project, I need a better grade of Log.

[PLJack]

Or like I do with my system of T tracks and clamps. Put your work anyplace on the table, it just needs to be square and I can take that off the tracks. All my jobs, origin is Center. Use my Pendant to goto the center of the work, Zero it all out raise the Z and hit Start.
Pictures from my Bear project, I need a better grade of Log.

That's pretty sweet as well. Maybe next spoilboard.
I'm glad to hear that someone else uses center origin. I see a lot of people talking about finding corners of material. I've never needed to do that. Must be certain types of work.

Thanks.

[PLJack]

Originally Posted by GME
I have a technique for setting steps per for the X and Y axes using 1 2 3 blocks and a dial indicator, if you're interested. Nothing very complicated, but the more blocks you have, the better. I used 12 blocks, which gave me a measurement distance of 33 inches. IMHO, it's more accurate than trying to read a scale. For my old eyes, I'd be lucky to get a measurement off a scale within .015" or .020".
Gary



Here is a drawing of the setup:

Lay out the 1 2 3 blocks as indicated for either X or Y. Clamp, or otherwise fix your dial indicator to your router. Zero where indicated. Command a move the distance represented by the number of blocks used. Read the distance moved by taking the distance represented by the blocks and either add or subtract the observe whether the dial indicator gives a + or - or zero. If zero, steps are right on. If a positive number, your move was longer than commanded by the amount of the dial indicator's reading. If negative, the commanded distance is short by the amount the indicator reads. Once you have a reading, reset steps and repeat until you have it set perfectly.
If you use this method, I suggest you measure the 3" length of each block, or better still, put 2 together and measure the 6" length. For most of mine, I went on the cheap side when I bought them. There off by + or - .0005 to .002. I measured them in pairs and added up the true total distance of travel.
Gary

Not seeing a picture. I would rather use a dial indicator for all my measurements.
My thinking with the ruler was that if I could get 900mm close then the shorter moves should be very close. Perfect would be nice though.
That being said I have not addressed backlash yet. Currently I don't have a lot of confidence that this machine will stay calibrated once it's as good as I can get it.


Thanks.

[GME]

Or like I do with my system of T tracks and clamps.

+1 on t-tracks.. I wouldn't trade them. Very versatile. However, I did it a little differently. My spoilboard is three layers thick. 3/4" mdf base. Then 1/2" mdf glued to the base layer. Route out the 1/2" layer for the t-tracks. Then a third layer (3/4") glued on and route out for the slot in the t-tracks. This technique leaves a lip of mdf over the edges of the t-tracks. Doing it this way, you can get by without putting mounting screws in the in the t-tracks. That said, I drilled holes through the base layer and mounted the t-track with machine screws, washers and nuts. Probably overkill, but not that much additional effort or cost.

Gary

[GME]

Not seeing a picture. I would rather use a dial indicator for all my measurements.
My thinking with the ruler was that if I could get 900mm close then the shorter moves should be very close. Perfect would be nice though.
That being said I have not addressed backlash yet. Currently I don't have a lot of confidence that this machine will stay calibrated once it's as good as I can get it.


Thanks.

I'm not sure why you cannot see the picture. I can see it. I'll try again. If it doesn't take, I don't know what I'm doing wrong. Gary