Have I lost my marbles? need to tinker

[rjw]

Have I lost my marbles? need to tinker with model H

As some of you might know, I bought a 20+ year old Ektelon model H in what turned out to be relatively easy to tune up and string some racquets with. I love the machine and the results, altho I've only strung my pair of apdgt's (2 piece) and an Irvin atw on a 115 sq. in. old Prostaff.

Having been involved in precision machinery, machining, cnc etc for the last 30 years or so, I did a pretty intense tune up of the old girl while learning how she works and the ins and outs of a vintage LO machine.

Now I think that I've lost my marbles.

After the tune up, I noticed that the brake disk under the table had a lot of slop in it, so even when locked down, it had a bit of play between the bolts and the disc...so I added a pair of nuts and now the brake is slop free.

I also tightened up the glide bar brackets, etc, squared them up and did all the maintenance as per the manual.

After 3 string jobs, they've come a bit looser...mostly due to me not tightening the heck out of the slotted head screws on the brackets.

But, even in an ideal setup, there will always be some play and also a fair bit of drawback. I've seen this also in non-glide bar machines as seen in a lot of the tube videos by members.

Now maybe you guys (and most) can live with this, but I have a need to tighten things up.

So , I ordered some linear bearings and rails and will attempt to retrofit this to my old H

Has anyone else ever tried something like this?

If it works out, I should have NO drawback at all and moving the glide bars around should tight yet effortless.

At the same time, I have slop in the bushings under the table, so I will be also attempting to retrofit some needle bearings along with a needle bearing thrust washer set to that area of the machine.

I have cnc machines, so outside of some material drops and my time, I should be able to do all this for around $150, plus if things don't work out, I'm doing it in such a way that the machine can be put back to how it currently is.

Does all this slop and play bug anyone else?

I know, I could save and buy a Wise , but I would still have all the slop.

Or have I lost my marbles? or maybe too picky?

Comments of any kind are welcome

tia

On a side note, my design for this will also allow me to string the first 2 mains with both clamps standing straight up, in that I am in no hurry, and like to alternate and not do 2 or 3 on one side, when doing mains...(just my style) For those not familiar withthis style of machine, it's design is such that you cannot get the glide bars close enought to each other , therefore clamps must be angled until more mains are done.

 

[tennisfu]

It bothers me but I just clean and lube regularly. I put white lithium grease in the grooves where the glide bar fit into after cleaning. It slides so easily that I can tighten the screws more and get hardly any draw back (a mm maybe). I have tried cleaning and greasing the turntable and it helps but still isn't great. The weight of the table is heavy enough that there is still some drag. If I give it a decent push, the table will spin about 1 1/2 revolutions.
Putting ball bearings in would be great but I have no clue how to do it.

 

[diredesire]

Often times, things like this bug me, but I think that's because I look at things like this slightly critically. I'm an EE by training, but I think it's all about the mindset. I wonder why things work the way they do, and if/how they can be improved.

I recall you're a retired Tool & Die guy, so it makes a lot of sense to me that you're looking to retrofit. The unfortunate thing, though, is that 99% of the board doesn't have the experience/tools/materials to make a retrofit, otherwise there'd be threads on it, already

I think if you're interested in "fixing" some stuff on other machines that needs work done, you could do some interesting work

 

[rufusbgood]

The glide bar slop in the Ektelon H is pretty well known and the conscientious stringer will deal with this by pulling the glide bar snug up against the rail in the direction of string pull with one hand while setting the clamp with the other hand.

With your background, you'd probably find the True Tension machine more to your liking. It's machined and designed with an eye toward eliminating all sources of tension loss. Glide bar slop is negligible and the clamps are stubby so there is also no clamp tilt.

I will be looking forward to seeing what you come up with in the way of a retrofit. I hope you will post photos.

 

[rjw]

I don't mind the cocking of the bar to minimize drawback, it was expected even before I saw the machine.

I also actually like the LO tensioner, cause it has feel to it, gives character to the machine and so far, I really like how my racquets feel.

As a matter of fact, even tho they were both strung 10 and 11 days ago, and should be fairly loose by now, in that I've been hitting twice a day mosty, I still like the way that they feel and my test reel of Gosen sheep micro is anxiously waiting in the cabinet base of the machine. So far, I'm in no hurry to tear the strings out of either stick, just yet.

I could easily leave well enough alone and be happy knowing what I have and dealing with it, although I'm sure that the table shaft and bushings are a bit loose, A 1" shaft should ideally have around .001" clearance, call it .002 or .003" for an easy spin, but mine has over .007" which is what I would consider worn

I will address this maybe late tomorrow and should have it on needle bearings fairly quickly., but it's not something that I would offer to do for anyone, because the way I will do it will require machining the tube for proper fit.

Anyone who has slop there could have new bushings put in and/or a tighter tolerance shaft and probably be very happy. The table rides on a simple washer, which I will replace with a 3 piece needle bearing assembly (cost only a few dollars)

The conversion from sliding glide bar mounts to linear bearings and rails, might be rather painless. If it is and it works, I may make a few kits for anyone interested.

I think that it will help me to work a bit quicker and I like the upgrade to being able to bring the glide bars much closer together and be able to do all the mains while not having to ever clamp with the serrated portion of the clamps and if desired, in a straight up position. It should also feel really smooth.

I will post pictures as I go along, just to keep this great group up to date, even if it's just out of curiosity.

I should also be able to show before and after dial indicator readings of stuff like endplay, slop and drawback and perhaps even some video of it in action, but don't expect to see a pro stringer in action...lol

btw: I am not retired, just retired from t&d

 

[rufusbgood]

I will address this maybe late tomorrow and should have it on needle bearings fairly quickly., but it's not something that I would offer to do for anyone, because the way I will do it will require machining the tube for proper fit.

I understand the plan and don't want to talk you out of it. I will just say this: There's something to be said for drag. When you are weaving your crosses, having a turntable that will go into dragless rotation at the slightest touch isn't necessarily desirable.

 

[rjw]

I understand the plan and don't want to talk you out of it. I will just say this: There's something to be said for drag. When you are weaving your crosses, having a turntable that will go into dragless rotation at the slightest touch isn't necessarily desirable.

Good point....On one hand, that could be a problem, but as it is, it's pretty smooth, but what I don't like about it is that it cocks when pulling tension and then springs back when releasing.

Perhaps my machine just has a bit more wear in that area than most???

I'll do the retrofit and see what happens. I could always add a tad of drag and still eliminate the rocking or maybe use a bit of brake?.....good call though....

thanks!!

 

[diredesire]

I understand the plan and don't want to talk you out of it. I will just say this: There's something to be said for drag. When you are weaving your crosses, having a turntable that will go into dragless rotation at the slightest touch isn't necessarily desirable.

THANK YOU for pointing this out. The 5800 ELS i have is extremely free rotating, and I have to lock it down when I weave. Drag is GOOD.

Trust me rjw, too smooth will give you fits

 

[rjw]

THANK YOU for pointing this out. The 5800 ELS i have is extremely free rotating, and I have to lock it down when I weave. Drag is GOOD.

Trust me rjw, too smooth will give you fits

Point is well taken. I'll go for minimum rock, but a bit of drag.I know just hoe to do this...'lightbulb'

thx

 

[kato669]

I understand the plan and don't want to talk you out of it. I will just say this: There's something to be said for drag. When you are weaving your crosses, having a turntable that will go into dragless rotation at the slightest touch isn't necessarily desirable.

Definitely. I re-greased the spindle on my stringer a few months ago. now when I'm doing crosses the *&($( thing keeps moving too freely now! Drag/Friction works well in this case.

 

[rjw]

Definitely. I re-greased the spindle on my stringer a few months ago. now when I'm doing crosses the *&($( thing keeps moving too freely now! Drag/Friction works well in this case.

Maybe you guys are misunderstanding, or I was not clear.

It's not that the table doesn't move smoothly enough, it's that it rocks or cocks when I pull tension. I'd rather that it didn't. I'm sure that even on a new machine, there is some rocking, if there wasn't then the table would not turn very freely.

I took mine apart and I find that there is way more clearance between the 1" shaft and the bronze bushings, than there needs to be. Hope this makes sense...remember that the machine is over 20 years old, although I find it hard to believe that it was ever really tight, considering how loose it is now

I'll try to get a short video up later, to show the slop with a dial indicator. Then it should be as clear as mud..:twisted:

 

[mad dog1]

my prince neos 1000 was pretty slop free. without a bearing mounted spindle, there was no noticeable play in the turntable. it was as tight as my gamma 6004 which does have a bearing mounted turntable.

 

[rjw]

my prince neos 1000 was pretty slop free. without a bearing mounted spindle, there was no noticeable play in the turntable. it was as tight as my gamma 6004 which does have a bearing mounted turntable.

I believe it. When I bought my old H, the seller told me that he bought the machine over 20 years ago and only strung maybe 50 racquets. Whil I am not unhappy with the machine, I think that he probably bought it used and whoever had it before him might have strung 1000 or more racquets...I forgot to ask if he bought it new!!!!

No way there's this much slop after 50 or even 500 racquets.

 

[jim e]

Maybe you guys are misunderstanding, or I was not clear.

It's not that the table doesn't move smoothly enough, it's that it rocks or cocks when I pull tension. I'd rather that it didn't. I'm sure that even on a new machine, there is some rocking, if there wasn't then the table would not turn very freely.

I took mine apart and I find that there is way more clearance between the 1" shaft and the bronze bushings, than there needs to be. Hope this makes sense...remember that the machine is over 20 years old, although I find it hard to believe that it was ever really tight, considering how loose it is now

I'll try to get a short video up later, to show the slop with a dial indicator. Then it should be as clear as mud..:twisted:

From your description is sounds like the bronze bushing is most likely worn. You may be best to contact tennismachines dot com and see if they have any replacements. I'm sure they would be of help if you called and spoke to them directly, as from what I have heard they know these machines inside and out. I have a different machine, and the table moves very freely, and there is absolutely no rocking at all, not even a fraction amount.I would think that your table should be rock solid.

 

[mad dog1]

my neos 1000 turntable sat on a thick flat washer so like jim e mentioned, if the bronze bushing is indeed what i called a flat washer, then yeah, it sounds like that may be worn. if so, it should be a very inexpensive fix. the neos table rotated very smoothly considering it was bearingless.

 

[rjw]

Ok...here is a short video showing the play in my table. I am using a dial indicator to show the rock or play between the tension bar (which is clamped rigid and the part of the table where the head of a racquet is fastened.

This is NOT a true indication of the actual play (which is must less) but maybe you can see the rocking (not totally eveident) but what is unquestionable is the dial indicator reading which shows around .055" movement or just under 1/16"

Yes it bugs me and has to be corrected...Stay tuned for part 2..the fix


http://www.youtube.com/watch?v=KND1r-8DnSU

 

[rjw]

After the minor retrofit

Ok, here are the results...plus how I bored and measured the tube, just in case you are interrested.

http://www.youtube.com/watch?v=2IHdNcO06U4

Waiting on the linear bearing stuff, which should be here soon and then I will attempt to retrofit and tighten up the glide bar assemblies

 

[MAX PLY]

Nice job. Plus, loved hearing The Doors in the background.

 

[rjw]

Nice job. Plus, loved hearing The Doors in the background.

Thanks.....Can't hear the radio with the machines running, but it is nice to catch a good tune when I shut them off.

As far as the actual mods go, I got exactly what I wanted....I did have to face the top of the tube tho, it was bandsaw cut and more than a little crooked !! I hope that the newer Neos models are machined a bit better!!

Stage 2 coming soon....

 

[rufusbgood]

Looking forward to the linear bearing mod. Can't picture at all in my mind what you are planning to do and am eager to see what you come up with.

 

[rjw]

I am supposed to get the components tomorrow....maybe?

We'll see what happens, if Mr. UPS is nice to me...

 

[rjw]

Mr. Ups was nice...now I need some free time....

 

[jim e]

Mr. Ups was nice...now I need some free time....

Does that mean he brought you the marbles that you lost?

 

[rjw]

Does that mean he brought you the marbles that you lost?

Maybe 1....but most are still lost somewhere

 

[rufusbgood]

How goes it with the linear bearings?

 

[rjw]

How goes it with the linear bearings?

Kind of as expected....a little too slippery....the ball bearing slides move around too much when tension is released...I might swap them out for bushings, but having played around with this for a while, I might go another route....simpler, cheaper and hopefully a lot less drawback.

With the oem stuff, I was getting around .050" drawback, at the moment, I'm at around .030" . so, almost cut in half, but still no cigar...

The whole contraption looks pretty wierd tho....lol

 

[rufusbgood]

The whole contraption looks pretty wierd tho....lol

I really can't picture how you are using these linear bearings. Any chance of a photo?

 

[rjw]

I really can't picture how you are using these linear bearings. Any chance of a photo?

I was going to wait until it's finished, but what the heck.....give me a minute....at least it'll be something a bit different

 

[rjw]

Ok here's one.....let the flaming begin...:shock::twisted:

 

[rufusbgood]

I'm surprised this set up still has play in it. But even if you had managed to eliminate play, I don't get how you'd switch from stringing mains to stringing crosses.

Also, those clamps are really dated. You might want to keep an eye out for a pair of used Neos clamps on the big auction site.

 

[rjw]

I'm surprised this set up still has play in it. But even if you had managed to eliminate play, I don't get how you'd switch from stringing mains to stringing crosses.

Also, those clamps are really dated. You might want to keep an eye out for a pair of used Neos clamps on the big auction site.

How about another picture?

I'm thinking of making a set of shorter clamps, then less flex (possibly) Also, these old ones have problems getting between strings when doing crosses.

I think maybe a 3 jaw design like I've seen on bab sensors might be more universal.

 

[rjw]

btw: changing from mains to crosses takes about a minute....the shaft end supports are doweled to holes in the lower plates, so alignment is perfect in both directions. thumb screws (underneath) lock everything in place.

I am still working on a much cheaper solution....not that many might even think that there is a problem to begin with, but I can be totally anal and need to do more testing....

 

[rufusbgood]

Well, I'm impressed, and I don't even string on an Ektelon. Where are all the Ektelon owners?

 

[rjw]

Well, I'm impressed, and I don't even string on an Ektelon. Where are all the Ektelon owners?

Did the 2nd picture clear up how the crosses are strung? It's a pretty neat setup and moving the rails around is lightning fast and smooth

I think that the Ektelon owners are busy stringing racquets....lol and NOT paying attention to my madness

 

[rufusbgood]

Did the 2nd picture clear up how the crosses are strung?

Your explanation about the dowels cleared it up. Very clever design.