Full Version: Xenetech 1624 question
From: Cindy (CINDYM) [#1]
3 Jan 2007
To: ALL
Hi all - before I have a service person come down and try and figure out what might be wrong with my engraving machine, let me run by those of you out there that have a Xenetech rotary engraving machine and see if anyone else has run in to this problem, and if so, what the solution was.
My Xenetech is era around 1991 or so. It is a 1624 model (earlier than the 1625).
Problem: intermitantly, when engraving in plastic, the spindle will not go all the way down to the material and engrave. It sky writes. Sometimes it lowers a bit, sometimes no lowering at all. There doesn't seem to be any rhyme or reason for the problem. I can be engraving and the spindle will engrave all letters fine on the plate, but when I move to the cut out phase, the sky writing begins. Or, perhaps it will engrave the first letters, but in the middle of the sign, it begins sky writing. So far, after it does this, if I move on to some engraving jobs on brass, using the other settings, when I return to plastic, it begins engraving again just fine. Last night, it started sky writing towards the end of the day. I turned off everything, blew dust out of the control box, reset, restarted everything and it still was sky writing. Then this morning, everything is fine and it engraved on plastic fine.
Don't know if it is a board glitch problem, where the board is wearing out or? There are no burn marks on any of the boards. Nothing appears or smells like it is overheating.
The problem could be in the toggle switches I guess, or ??
Any ideas or suggestions would be appreciated. I don't want to get 'stranded' during a big job, so am trying to figure out the problem a head of time and get whatever it is fixed now. But it is like having a problem with you car - it is so random, with no reasoning, that I can't even really describe the problem because no one thing seems to cause it to sky writing, and no one thing seems to fix it.
Ideas??
Cindy M
From: Harvey only (HARVEY-ONLY) [#2]
3 Jan 2007
To: Cindy (CINDYM) [#1] 3 Jan 2007
In generalities, not familiar with that machine.
It sounds like one of two things.
1) There is binding in the spindle travel path. Either the spindle holder or the stepper, or the connection between the two. I have seen steppers, especially old ones, seem to go defective, when the only real problem was that the oil that was in the sleeve bearings of the motor dried out and gunked up. Even had a FAX machine cutter motor do that.
2) The driver transistors have gotten 'soft' and are overheating. This can be an overheat due to possibility 1.
I would check the mechanical and motor oil first. Do not use car oil to lubricate these bearings, it will itself dry our and gunk up within a year. A good grade of oil may seem to do the same as it dissolves the gunked oil, but a second lubrication will then give years of service.
After lubing, spin the motor a bit and wipe off all of the oil, this tends to remove some dissolved gunk. Then re-lube.
From: Stunt Engraver (DGL) [#3]
3 Jan 2007
To: Cindy (CINDYM) [#1] 4 Jan 2007
Without real knowledge of Xenetech equipment, I can echo what Harvey said, in that, the possible hinderance of the up/down travel of a spindle can be caused by a poorly lubricated, or "sticky" lubrication of the spindle.
If that's not the case, it points to an intermittent electronic malfunction.
From: joyce (JLADY) [#4]
3 Jan 2007
To: Cindy (CINDYM) [#1] 4 Jan 2007
It sounds like the proximity sensor.
I was having basically the same problem, it would not touch the material on some characters randomly then next one would engrave again.
I called tech support and they had me do a few easy tests and figured it was the proximity sensor.
In case you don't know what that is it under the motor next to the spindle and has a wire sticking out the top and has a red light when not touching material, if it touches the material the light should go off.
I think they cost about $150.00.
From: logojohn [#5]
3 Jan 2007
To: Cindy (CINDYM) [#1] 4 Jan 2007
Most engraving plastic does not have that problem but when I profile blanks from laserable plastic it is very bad.
If their isn't enough spring tension, once up it will just stay there. You can just turn the knob to increase the tension.
The other thing is if your z stroke, z float settings are high enough. If you have 0 or .001 in the z float there is no downward pressure other than the weight of the spindle so it my not have enough downward pressure.
Also make sure you have the full automatic cutter set checked or it will stop trying to come down before the nosecone or diamond tip hits the surface. The manual and no cutter set are for burnishing and rotary engraving without a nosecone. Sorry to state the obvious but I don't know what you know and what you don't. I still learn things I have been doing wrong or at least there might be a better way.
Attached is my settings for profiling. On the laser material the z float could be increased to .1 and higher spring tension. Sometimes if I want to run it fast I actually apply down pressure with my thumb as it is moving so it doesn't ride up over the material that doesn't get vacuumed away. Also increase the rotation speed to about 8 on the spindle knob on the machine itself.
I assume since you are doing plastic you have the spindle turning fast. If you are doing diamond drag and the spindle is moving very slow 1-2 or you have it off it isn't turning fast enough for the belt to follow the shaft downward and it will hang up and think it has sensed the surface before it has come down all the way. In drag mode the spindle motor only turns on breifly during descent so the belt doesn't hang up and then turns off.
From: John (ICTJOHN) [#6]
3 Jan 2007
To: Cindy (CINDYM) [#1] 4 Jan 2007
Cindy,
I hope what Harvey & David mentioned about your machine's condition is not the case, but you never know.
Usually that scenario is caused by a bad proximity switch or a loose connection on the switch, mine was less than $20.00.
The switch senses the material surface and then lowers the spindle the amount in thousandths of inches you have set in the software. (on the F-1 screen it is Z Float) The switch will be somewhere next to your spindle, mine is on the left side.
hth,
EDITED: 3 Jan 2007 by ICTJOHN
From: Pedaler (ROYBREWER) [#7]
3 Jan 2007
To: Cindy (CINDYM) [#1] 4 Jan 2007
Most have already been covered, but what you describe could be caused by:
--motor brushes worn. Have you checked them lately?
--broken wiring (least likely but extremely hard to track down)
--bad prox sensor (closer to $150 --- ITCJohn has a different model)
To save you some time, before calling tech support,
1. check brushes. I always recommend having an extra set available in cases like this so a new set can be inserted even though the current brushes look OK. assuming brushes OK,
2. run several jobs using manual cutter set at start. Almost definitely this will eliminate your problem and you'll need to purchase a prox sensor. logogjohn gave instructs recently on how to replace, but Xe tech support will walk you through it if you like.
If Manual Cutter Set at Start is not in your comfort zone, click on XGW's built in help and search for "Manual Cutter Set at Start" where explicit, step by step instructs will walk you through it.
From: Cindy (CINDYM) [#8]
4 Jan 2007
To: Pedaler (ROYBREWER) [#7] 4 Jan 2007
I think, from reading all this great information, the proximity sensor could be the problem. That came up during my discussions with Xenetech techs, but like I said, without it being constant, it has been really hard for a tech to narrow it down. The light is still on, and it is just real random on when it works and when it stops coming down to the material. It never happens when I am burnishing or diamond drag engraving, only engraving plastic.
I'm pretty comfortable with my machine and doing repairs to it myself, so I think I'll order a sensor and replace it and see what's what. The machine has been a great workhorse for so many years, that if this is the second problem to come up, I think that is pretty good.
Brushes were replaced in the spring of 2006 (for the first time ever, shame on me!). They were really worn. Also switched two boards to fix a problem in Aug or Sept. Switching the boards to new slots solved that problem. Oh, and I bought a new spindle last year too.
Thank you all for your suggestions.
Cindy
From: Harvey only (HARVEY-ONLY) [#9]
4 Jan 2007
To: Cindy (CINDYM) [#8] 5 Jan 2007
That raises a big possibility of micro corrosion, not unusual in an older machine. (High humidity increases this possibility.)
With the unit unplugged, remove and replace every board. Then remove and replace every connector. This will scrape off the micro corrosion from the contacts and you should be good to go from that standpoint for at least five years. While you are at it remove and replace each chip that is in a socket carefully being careful of static charge. (Touch the board and hold it before touching the chip, keep holding it and the chip until you replace it. Do not work on plastic or sit on a varnished stool.)
If a connection is not air tight, very few are, the contact material will form oxides very slowly. Humidity and sulfur fumes increase the oxidation rate and the sulfate rate. It is a natural occurrence. When there is enough corrosion the resistance goes up and at some point it gets high enough to be intermittent in operation, then fails.
Hopefully this simple solution will work for you.
From: logojohn [#10]
4 Jan 2007
To: Cindy (CINDYM) [#8] 5 Jan 2007
You were lucky. I forgot to check mine periodically on the Xenetech
and my first reminder was the motor stopped working. After the brushes were gone the wire springs pushing them in got tangled in the spinning part and destroyed the motor.
Had to buy a new one for many hundreds of dollars since I couldn't wait for it to be rebuilt. I got spoiled on the old Carter/Hermes motors would just stop working but not destroy themselves. The grassy knoll crowd might think Xenetech designed it that way to sell more motors. (devil)
EDITED: 4 Jan 2007 by LOGOJOHN
From: Cindy (CINDYM) [#11]
5 Jan 2007
To: logojohn [#10] 5 Jan 2007
I can't remember what happened to tell me to check the brushes - obviously something stopped working. I can't believe I didn't ever check them before they went bad. There was about an 1/8th of an inch left of the brush part before going in to the spring. In fact, I felt like an operating doctor trying to get the part out because there wasn't any 'spring' left to the spring to pop the brush out it was so far gone.
I'm usually pretty proactive about machine maintenance, but completely overlooked the brushes.
The sensor is going to be ordered and replaced soon. I'm pretty sure that is the problem for this time. We have little humidity issues this far in to the valley on the west coast - nothing like the eastern part of the country. I'll start with the sensor and see where I end up. With a machine this old, it could be multiple things going on.
I've really decided to keep this machine going because I love it, but I will be purchasing a laser also, hopefully in this year. That will help if the engraver ever goes down - back up machines are great to have. Lessens the stress factor by a bunch.
Cindy
From: Harvey only (HARVEY-ONLY) [#12]
5 Jan 2007
To: Cindy (CINDYM) [#11] 5 Jan 2007
Your description tells me why you replaced the brushes. It started sputtering, going intermittent. Some brushes are made with short springs to cause that to happen. others have a slot down the side that ends near the spring. There is a tab in the housing that latches on to the end of that slot when it gets too short and stops the brush from being pushed any farther.
The Dahlgren motors used the slot system and saved many motors. Of course the RF snubbing system in the motor burned out the commutator really fast, duh.
From: Cindy (CINDYM) [#13]
5 Jan 2007
To: Harvey only (HARVEY-ONLY) [#12] 5 Jan 2007
This is how I felt when I saw those brushes
:-$
I was so ashamed of myself for letting it get that bad.
cindy m