Summa T750

[advsign]

I purchased a used Summa T750 cutter and everything works fine except on about 40% of the time when I send a cut job to the plotter, the first cut (shape or letter) does not get cut. Example like one side of a O or T and etc gets mostly skipped by the blade. Has anone else had this problem?

Also Summa offers free tech support but is that only for the orginal owner?

Thanks,
Ken

[Gene@mpls]

Summa tech support is wonderful. Call 1 800 323 9766- I have 2 of the
T750s and love them. Gene

[Colin]

advsign: did you get this fixed? I think I know what it is.

[advsign]

No I did not get it fixed. I did call Summa and they said to try a new $1000 head unit.

What do you think?

Thanks,
Ken

[Colin]

I'll assume that your "T" model is the same in this respect to my "D" model.

There is a plastic cover over the cutting head (affixed by 2 small phillips screws). Remove this cover, then you may find a very small (1/8" diameter) black rubber pad that a vertical adjustment screw bottoms out on. The adjustment screw over time makes a little indent in this pad and it can kinda stick there. If you very carefully remove this pad (it is glued down) and relocate it slightly so that the screw now comes down on a fresh part of the pad, you may find that this solves the problem.

Let me know....


Woo hoo......my first post with my new computer!

[i45signs]

I Also Have A T 750. When This Has Happened To Me I Changed The Blade And It Fixed The Problem.....

[jbennett]

I had this happen for a while with my D750 and I called Summa. They directed me exactly as Colin said in his post. The "solenoid cushion" (part # HR29-134) had a hole almost all the way through it. After turning it over and re-gluing it with the other side up, my cutter cuts much better than it has in a LOOONG time. I did order the correct replacement today and the $8.00 small rubber pad is on the way :biggrin:


jbennett

[fatpinfield]

Colin got right on. Had similar problem on the D620, along with some nippling. Replaced that little pad and all problems went away. I love that Summa.

[onemansignshop]

I had this "leaving a gap" problem a few years back with my D750 & had to ship the entire cutter (less stand) to Seattle for repair. While it was there I had the unit converted to a T750. The tangential head has been great (able to cut down to a 1/4" font height) but now that blasted gap problem is back again. It ALWAYS leaves a gap at the beginning of the cut. I've worked around this by inserting a registration mark at the lower left which would be the first cut. But now it will also leave a gap- sometimes quite large in the middle of the job requiring recutting that letter. Aggravating!
The rubber cushion sounds like it is indeed the culprit. When I push down on the head (power off) when the cutter has been sitting, I feel a slight resistance- as though it's slightly stuck. Once I do that, the head will go up & down freely (manually). I've tried doing this right before I cut a job but it still leaves the gap. Does anyone know where this rubber cushion is located on the T750? I've looked & I can't spot it.

Tom

[jbennett]

The pad is called a solenoid cushion. It is easy to change, and it fixed my problem. I do wish that mine had a tangential head, but it does mainly what I need it to. If you call Summa support and tell them that you need a solenoid cushion, they will hook you up. The shipping is a lot more than the part :tongue: I'm not familiar with the T750 head, but Summa support will be able to tell you right away. It is under the plastic head cover on my d750.

jbennett

[Colin]

First, you must remove the plastic cover as shown in "Pad 1".

You can then see it........as shown in "Pad 2". It's a good idea to replace it every year or two, so get a few of 'em.

[onemansignshop]

My T750 head looks quite different than the D750. One big difference is that the normal position of the T750 head is up where the normal position of the D750 head is down. I've attached are a couple of pics.

Thanks gang.

Tom

http://www.signtech-rta.com/T750head-up-thumb.jpg (http://www.signtech-rta.com/T750head-up.jpg)http://www.signtech-rta.com/T750head-down-thumb.jpg (http://www.signtech-rta.com/T750head-down.jpg)

[Colin]

Yes, that T-head sure is different. In it, there appears to be a cylindrical copper winding with a cover that moves up & down. I wonder if there's a piece of dust or debris in there causing it to stick?

[Mac34]

Before buying any parts, isn't it still under warrantee? If I'm not mistaken, mine came with one for 3yrs.? (T-Series / 30"). I've only had one small issue with the cutter, and when I called tech support, they said to bring it right down THAT DAY! It took me about an hour to get there, but the problem was fixed, back on the road I went, and I was back to work that afternoon! Before buying the Summa, I was torn between two different brands, and from some negative feedback I heard about Summa's tech support, I went with the "other" brand. I hated the thing from day one, and ended up trading it in towards my Summa. I understand that many have different experiences and opinions towards different companies, but just wanted to go on the record as saying my experience with Summa has been absolutely great! They'll get my next cutter purchase for sure! (Sorry to go off on a tangent, but just wanted to remind you that you may have a warrantee, and they seem to be very good about staying true to their word). Good luck!

[signboy52]

I've got the T750 and have the exat same issues with it skipping the first cuts of the job. What's the solution for this plotter? I can't see or find the solenoid pad.

[Colin]

Please read the thread. The "T" model is different and apparently doesn't have the rubber pad. Have you tried contacting Summa?

[bmxovich]

Give Summa a call. I just picked up a used T750 two months ago and they have been VERY helpfull with any questions I've had...

[ColesCreations]

Not sure if this is your problem, but we've had some problems with things getting cut off when close to the edge in winplot, the document size "shrinks" to biggest design.
I added a bigger rectangle around everything, sent to winplot, and deleted the rectangle.
If this does not help, it may be cheaper than a new head, to put a letter or something for the cutter to start on...
Ours is a T-140 with OPOS, great machine!

[Alan_F]

I have just aquired T1400 pro, and i wont call summa cutters as i love them my previous one was a D60 and yes i had a replacement head once because of the sticking head syndrome, (wish i had used the pad trick) but now with the same thing happening to the tangential cutter i am trying to solve this as i aint paying £900 for a head fitted.

I bought the machine for £450 thinking it needed a new head and thought i would take a risk, i competely stripped the machine as it had been stood in a bodyshop for 2 and a half years, including removing the head.

Now when you remove the head on these machines, you must mark the height on the carriage, and put the head back in the same position theres just 3 screws holding it to the carriage plate, which dont have to be removed fully just slackened off, you must remove the circuit board and disconnect the drive motor wires from the circuit board, a good tip here is if you do remove the belt to the coil then make sure you mark up the blade holder and wheel on the motor as when its sets itself to zero, to start a cut you must make sure that the blade is in line.

I am going to remove the head on mine and turn it upside down and give it a good spray with (Ipa) Alcohol, and let it run down the inside of the cast iron drum leave it for ten minutes whilst working the head up and down and then turn it back over to let the ipa drain out and dry. This should get rid of the sticky lip, of which i am told happens to lots of solenoids, not only in cutters, also be careful of using oil like wd40 or 3 in 1 as dependant on the consistency it can work like a seal and create a vacuum when the coils going up and down and can actually make the sticking problem worse.

Also dont forget on these summa tangential cutters, the blade on the T knife doesnt go all the way in and tighten up to hilt, for a normal T knife when new set your pressure to around 70g, then slowly wind your knife in quarter turn at a time till you get a clean cut, without going through the backing, if you are having the starting problem then wind your pressure up to say 140g, and set your knife blade again it should cut fine at the start, till you can get chance to take a look at it.

I'll let you know how i get on

Alan

[Alan_F]

I think i may have found the cushion on the T head,
behind the head coil there is a pin that runs up and down in a plastic sleeve that acts like an end stop, to stop the coil bottoming out when i get chance i will have a look to see if its worn an dpac k it out a little, to see if it fixes it.
Alan

[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.

[onemansignshop]

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]

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]

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]

Thanx folks, you just saved me $1500.

[tec master P]

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.