Need help with tension head on used Alpha Revo 4000.

#1
Hey guys, first post in this subforum, and looking for advice with my new machine.

Recently bought an Alpha Revo 4000 on the Bay. This is my first machine ever, and the first time even stringing a tennis racquet. I set up the machine, and everything seems to be setup propery on the racquet mounting system side(Besides the brake knob missing).

My problem comes on the tension head side. The tension head is wobbly when I slide it on to the rails, and I am not sure how to get it secure. Another issue I am having is the clamp that holds the string is not locking the string in place, effectively failing at even pulling the string. I tried to tinker with it, but have no idea how this tension head is supposed to clamp and tension the string. Can someone help me out here? I have added pics of the tension head.http://imgur.com/a/8MwHM
 

Dags

Professional
#2
Issue 1: how wobbly are we talking? Mine always had a little play in it, but never to the extent where I feared it might cause a problem.

Issue 2: after you feed the string through the gripper, pull the string at an angle to the side to create resistance. Turn the crank with your other hand, and it should grip. When the lever pops out, it activates the brake. Hold onto the handle when you push the lever back in to release the brake, otherwise it will spring forward (and probably rap you on the knuckles).
 

struggle

Hall of Fame
#3
Yes, you have to physically "close" the gripper and as Dags stated above, often
just pulling the string to the side abit will engage the gripper.

I now have a wise head on my L/O machine but yes the tension head will have some play/wobble.
 
#4
Wonderful! When I pulled the string to the side, the clamp automatically gripped the string. I am going to wait until I recieve a tension calibrator in the mail, and try my fare at using it. On second thought, it is wobbly but not overly so. I think it will work for its intended purpose. Thank you both, appreciate the advice.

Also, one more question if you don't mind. On the frame supports at 12 and 6 oclock, one of the yellow plastic pieces is missing, so it is only metal that would be supporting the frame in that area instead of plastic. You can see it in the alpha revo 4000 pictures. Do you think this would cause too much stress to the frame in that spot, or do you think it will be okay?
 
#6
wobbly is normal.

You gripper has an adjustment screw on the back of it with a sping on it. If you screw the strew in it limits the travel on the gripper so it will not hold the string. Yours is all the way in. screw it out.
 
#7
Notice in the picture below the spring loaded limit screw to the right side of the tensioner. This limits the travel of the string gripper, and there is less than 1/2' of space between the stop and the screw. That how far the gripper can travel and the less it travels the less it grips. Turn the screw out and you have more travel and more grip.
 
#9
Call Alpha immediately do not string a racket without the pads in place.
I agree. Do not string a racquet without either the Alpha pads or some sort of other cushioning on the supports. I fashioned some cushioning on my machine's support towers using rubber sheeting with adhesive backing purchased on the 'bay site. Strung over 100 racquets without any issue.
 
#10
Thanks for all the help guys. I tightened my gripper and contacted alpha for the missing parts. They shipped them promptly, and very reasonably priced. Am waiting on a tension calibrator to string my first racquet!
 
#12
Ok guys, so I have been tinkering on the tension calibration on my machine. Using a digital luggage scale, my machine readings are consistently 4 lbs lower than what the mechanical tension head reads. I set the tension to 54 lbs, for example and it consistently hits 50 lbs +/- .5 lbs once settled(if the break fully engages) Peak tension would be about 51.5 lbs. Should I adjust the tension head, or is this normal with a lock-out machine? I have read that the tension set on a lockout should be about 5 lbs higher than CP. The string I am using to adjust tension is a synthetic gut. The luggage scale is quite close to the fixed clamps and tension head. I measured the string multiple times(~20 times) so I believe it is adequately stretched.

While testing, sometimes the break would not fully engage, and the measured tension was significantly lower(sometimes 15-20 lbs). It would reach peak weight, and then slip back a few millimeters. Is there some adjustment I can make to the machine so this doesn't happen? The more I started testing the tension, the more often it would happen. At the time, I would rotate the lever approximately 7-8 seconds to tension. While rotating the lever before lockout, it feels as if the break is already ever so slightly brushing up against the disk, but not engaged. Once it engages, it sometimes slips. Can anyone give some advice on my dilemmas please?

Edit: Strangely enough, the break seems to activate more consistently when I turn the lever to tension in about 3 seconds vs 7-8 seconds of turning til lockout. Don't know what to make of this. I thought it was good practice to tension the string very slowly and consistently to pre-stretch the string a little bit.
 
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#13
Your crank speed is too slow. The longer times are stretching the string unevenly. And your LO is not going to LO until it senses the tenison is greater. Just crank it until it locks and that should be 1-2 seconds. Be consistent. You should also calibrate your tension so that the brake engages at your desired set tension. You are confusing CP with LO. With CP, you can set the tension and it will pull until you clamp. You do not want to emulate a CP with a LO because you cannot pull that long with slow cranks and BE CONSISTENT. 3 cents.
 
#14
Ok guys, so I have been tinkering on the tension calibration on my machine. Using a digital luggage scale, my machine readings are consistently 4 lbs lower than what the mechanical tension head reads. I set the tension to 54 lbs, for example and it consistently hits 50 lbs +/- .5 lbs once settled(if the break fully engages) Peak tension would be about 51.5 lbs. Should I adjust the tension head, or is this normal with a lock-out machine? I have read that the tension set on a lockout should be about 5 lbs higher than CP. The string I am using to adjust tension is a synthetic gut. The luggage scale is quite close to the fixed clamps and tension head. I measured the string multiple times(~20 times) so I believe it is adequately stretched.

While testing, sometimes the break would not fully engage, and the measured tension was significantly lower(sometimes 15-20 lbs). It would reach peak weight, and then slip back a few millimeters. Is there some adjustment I can make to the machine so this doesn't happen? The more I started testing the tension, the more often it would happen. At the time, I would rotate the lever approximately 7-8 seconds to tension. While rotating the lever before lockout, it feels as if the break is already ever so slightly brushing up against the disk, but not engaged. Once it engages, it sometimes slips. Can anyone give some advice on my dilemmas please?

Edit: Strangely enough, the break seems to activate more consistently when I turn the lever to tension in about 3 seconds vs 7-8 seconds of turning til lockout. Don't know what to make of this. I thought it was good practice to tension the string very slowly and consistently to pre-stretch the string a little bit.
I guess it's normal to see 1.5 lbs difference between the peak and the settled. Mine shows the same thing. I calibrate the tension to the peak, though. The settled tension can be different string by string, so the peak tension is more reliable.

5 lbs difference between LO and CP seems too much. I don't remember what thread but there was an experiment of LO and CP using Wise 2086. The difference in DT was 2-3 lbs. But playability was identical despite the difference. So be careful not to be so straightforward and increase tension.

15-20 lbs lower should indicate something wrong. Where does the slip back occur? I just can't imagine how it happens.

There're people who believe in slow and/or long pulling. I hate stretching string, so I pull it quickly.
 
#15
Ok guys, so I have been tinkering on the tension calibration on my machine. Using a digital luggage scale,
I have an old LO machine. I check the calibration of the Tension Head every 30 restrings.

I use a digital scale and a couple of old peices of 16 gauge (1.3mm) poly string. I crank rather quickly, taking less than 2 secs to engage the brake. I repeat the process 3 times and check the tension reading on the digital scale each time. Seems to work fine. As @esgee48 suggests, I calibrate tension so that the brake engages at my desired set tension.

BTW, I have experimented with various cranking speeds. On my machine, faster cranking seems to produce more consistent string jobs in terms of SBS. (This is using 16G poly string in full bed).

IMO, whatever speed you crank at, make sure you are cranking in one smooth consistent motion until the brake engages.
 
#16
All string types do not settle at the same rate or to the same value. The tension your tensioner should be set to is the lockout value. Or what tension is reached when the tensioner locks. If you're in doubt call Alpha.
 
#17
Thank you Irvin, Karma Tennis, Esgee, and ElMagoElGato. I believe the problem was the crank speed. I have reduced my speed to about 2 seconds, and it consistently locks out properly. Also found your video on string machine maintenance, Irvin, and that helped in adjusting the machine properly. Thanks guys!
 
#18
Hi there - Different albeit somewhat related question. Got a Alpha revo used a few months ago. Just calibrated the tensioning mechanism for the first time, and since I did so, the locking lever catcher (I believe that is what it is called) now rests in a more "down" position, such that I have to manually lift it up to engage the locking lever. Previously, I was able to just push the locking lever back and it would "catch", but now I have to manually lift this. Does this make sense? Why would adjusting the tensioner change this? Thank you in advance for you help!
 
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