Summa T750

[Alan_F]

Wel ignore the last post as regards the head stop being on the side it doesnt work for upwards end stop its for the downwards motion.

but i sorted it all out, anyway, i removed the head from the carriage, and tipped it upside down and filled it with isopronal alcohol or ipa (get it from maplins) then i just worked the head unit in and out and used cotton buds to clean the lip of the coil and the shaft, also make sure the little brass bearing is seated in its base as mine was coming out a bit

its now cutting fine at 75g pressure through standard 3 to 5 year vinyl, and just leaving a slight indent in the backing paper, one last thing make sure you dont get ipa in the encoder motor it will run through and cause the encoder not to work till it completely dries out, so i hope this solves your T750, T1400 or whatever summa tangential head sticking problem you have, just added that so peeps can find this thread, as i searched for ages, also if anyone has any further info on summa's please post as its better than paying 1000's of pounds or dollars to get them fixed

Alan

 

[David Wright]

Alan, I have had my head problems with the T750 for a good while now, but I got to tell you I am not going to try your method. Besides being challenging for those of us that have limited mechanical skills, I see too many possible scenarios where things just get worse.

 

[Small Lettering]

My last post here regarding the T750 "gap" problem was 3 1/2 years ago. Sad to say, the problem still exists. After that post, I called Summa and talked to one of their technicians(?). His answer was that the head is an expendable part (like blades or the teflon strip) and must be replaced periodically. Yeah right, a $1000 expendable part! So I continue to live with the problem. Do I like it or Summa's answer? Absolutely not!

Years ago, before I ever got into the sign biz, I was a vending machine mechanic. An ongoing problem with vending machine components (namely solenoids) is "residual magnetism". This is where the solenoid plunger retains a bit of the magnetism after the current is removed. Increasing the air gap reduces the residual magnetism but it doesn't solve the problem. However, I've heard that there is a fix for the residual magnetism problem involving using a plunger made by adding silicon to low-carbon iron. I don't know the specifics, but my job is making signs, not solving Summa's problem.

 

[Colin]

My last post here regarding the T750 "gap" problem was 3 1/2 years ago. Sad to say, the problem still exists. After that post, I called Summa and talked to one of their technicians(?). His answer was that the head is an expendable part (like blades or the teflon strip) and must be replaced periodically. Yeah right, a $1000 expendable part! So I continue to live with the problem. Do I like it or Summa's answer? Absolutely not!

Ya, that's a shame. Summa makes great plotters, and their tech support is pretty good, so in a day & age where information, experiences, reputations etc are ubiquitous on the internet, you'd think that they wouldn't let this happen with you, and just fix the problem.

I remember a course I took years ago where the speaker asked the audience: "What is your job?" People gave their various answers, like "I'm a sales rep" "I sell widgets" "I'm a mechanic" etc etc. The speaker said: "No, you're all wrong. Your job is to serve the customer. Period. And when you make that your focus, regardless of what product/service you're involved in, you will succeed."

 

[David Wright]

It is a well known problem among users. If this was an automobile under the laws that govern that industry their would be a recall.

By the way, a new head is $1500, a refurbished one is $1100.

I am redoing a sign that had vinyl failure (translucent from Oracal).
No charge, maybe I should adapt to Summa's standards.

 

[artsnletters]

I also have a Summa T-750 plotter and it needs a new head as well, along with a T-610 24" plotter that is boxed up and ready to go back to Summa for a new head. I talked to the Summa tech guy, and he said , yes, the heads fail...but also, the heads are susceptible to voltage changes (surges, drops, brownouts etc) and said that possibly line voltage could pop the heads. Asked if any large amperage equipment is down line or on same main feed. I have a fabricator next door that uses a number of welders and mills on a different meter, but on same main line into building. I also don't have any surge protectors or battery backup units. He recommended me getting one. He also had some good ideas regarding D (drag) heads Vs. T (tangential) heads. I'm going to ship my T-610 back to Summa and have it converted to a drag head, as its almost a third of the cost and use it as a spare unit, THEN send my T-750 back for a T head rebuilt with a refurbished head ($400 less). It will still be way less than getting a new plotter and i should have 2 working plotters in the end. I hope it all works out....
Tim

 

[Chimuka]

I too have had this problem on my 610 / 750 & 1400 . My work-around is to push the hand button (oflline) just before I send the file to cut. Then I send the file. Next I walk over to the cutter and plunge the head manualy to "UNSTICK" the knife. Then I push the hand button again putting the cutter back on line again and start cutting. It seems to not miss that first cut this way.

 

[artsnletters]

mine actually quit cutting segments/incomplete plots....go to weed and accidentally rip the vinyl...its a PITA, but after all, i still like the summa's cutting better than the Roland & Graphtec's i've used.
Tim

 

[Alan_F]

The Summa Head can be fixed with a threepenny rubber "o" ring, the problem exists because the head cushion has collapsed inside the coil chamber, if you simply get a rubber "o" ring and get it slightly smaller than the shaft, hten warm it up in some hot water, and force it over the head block holder where the knife blade and wheelblock goes in it will sit snug on top of the head block and when the knife returns to its rest position the rubber "o" ring will act like a coil cushion and the head cutting will return to normal, i now have two mates who use this method and cant believe it was such a simple fix. so there you have it, simples, any one stuck on what i mean then message me. oh and the "o" rings i use i bought in a box from username "spratreader" Les on ebay.co.uk he has a shop called "amtools" and he has boxes of the correct sized one's

Alan_F

 

[signmanmatt]

First cut not made on T-750

Alan,

After reading the entire thread, A. I am amazed at how helpful people are. B. I am just about to try your 3 penny "O" ring fix, and if it works, I will post a pic and carry on with your simple, and masterful solution...I am just about to sell this machine...I have had it since 2003...and it looks brand new...and it always worked great...and this happened while I was demo'ing it...stay tuned...

 

[signmanmatt]

Alan-It worked!

It worked! I used a 5/16" ID and 7/17" OD rubber washer from a kit I had carried around for years (wondering, "why am I dragging this stupid "o" ring kit around?)
I nuked it for 1 minute in a tupperware bowl of hot water and wrangled it over the integral head with my tongue held just right and a toothpick for leverage...problem solved...thank you Mr. Alan_F...for taking the time to post this...if anyone needs an "o" ring..give me and address and I'll send you one...I am going to try and attach pics....

Matt

 

[dink60]

Love the "o" ring!

Thanx folks, you just saved me $1500.

 

[tec master P]

Summa T750 Sticking Issue

I recently had the problem with the t750 not cutting the first cut of most jobs due to the pad in the coil sticking when the cutter blade is up.
I did the three penny O ring fix as posted above, and it fixed it.
But it is tough to get the O ring around the block at the bottom of the blade component, and it doesn't leave much room between the media and the blade.

The solution: Orthodontic rubber bands for braces, works great.
It's easy to get around the block and it is much thinner than the O ring, leaving more room between the blade and the media.
No need to take anything apart, just slip the rubber band around and up over the cutting block and your done.