Mitsubishi sewing machine info

[cybernob]

Hi all,

just starting down the journey of sewing. I have a Mitsubishi DB-121 with 135x5 needle shaft but can't seem to find any information on the Mitsubishi DBs and history. Does anyone know what they are and the differences in the 12x models? Also is there an easy way to identify compatible parts?

G

[nylonRigging]

7 hours ago, cybernob said:

but can't seem to find any information on the Mitsubishi DBs and history. Does anyone know what they are and the differences in the 12x models? Also is there an easy way to identify compatible parts?

Identify finding parts , Most wear parts for that machine are Mass produced common/plentiful and economical that cross over to many name branded machines that ALL SHARE Same Parts . I have no idea what the 1st Parent machine design was copied for the Mitsu.DB's . But Mitsubishi made many thousands of them in a lot of different model and then a crapload of DB-### re-branded name models . It's a VERY Common high shank foot bottom feed design machine .
- -
 DB's don't get any respect on a leather forum , but It is, what it is  ..  DB's are good economical machines that sews pretty good for a ( bottom feed ) . it's a machine that uses it's primary feed with the bottom Dog Only . Sews great with 69E. has big selection of very narrow to Wide presser feet shapes, with  dogs, needle plates ..etc. Main design was for light/Med. fabric weight and moving fast RPM . but you can easy slow them down for more precision stitching for little more heavier materials .
The negative .. Your going to have 'Dog Tracks' on the bottom side of some soft leather, when using Presser foot or a roller foot . Sometimes that really matters, sometimes not , fabric never . But It a sewing machine that comes in handy for certain jobs, and handy one to keep around when you can have several machines in your stable .

I see that you have a Roller Foot/dog/needle plate,  on that Pic. and they sew good with roller when you 'slow them down' on the RPM with a nice servo . Roller foot good for certain jobs, and will delete the sliding/friction of a presser foot for a more fluid movement.
.

Edited March 27, 2021 by nylonRigging

[cybernob]

Hey thanks for the quick reply I really appreciate it. It's my first industrial and I've slowed it down with a servo and 45 pulley and built a new table top for it.

[Constabulary]

looks like some one bubbaed a 2nd tension unit form a Singer 212 or the like onto the machine. Interesting modification

The DB-121 is one of many other industrial plain sewer (straight stitch bottom feed) machines. I´m pretty sure a lot of parts (not all but a lot) are the same as on other machines of this class even from other brands. Juki 555 and the like are very similar. I´m pretty sure certain parts are standard parts and are interchangeable. Looks like some on retrofitted a roller foot + needle plate and feed dog.

Edited March 27, 2021 by Constabulary

[cybernob]

Yeah I'm not sure about the second tension unit. The person I bought it off was using it to do marine upholstery and must have added it for thicker thread but it looks like the original tension spring has been upgraded also.

I'm going to try and see if it makes any real difference to the stitch quality, still learning about this machine!

Thanks

[nylonRigging]

2 hours ago, cybernob said:

Yeah I'm not sure about the second tension unit. The person I bought it off was using it to do marine upholstery and must have added it for thicker thread but it looks like the original tension spring has been upgraded also.

I'm going to try and see if it makes any real difference to the stitch quality, still learning about this machine!

Thanks

I know my Mitsu.DB .. that was a weak point for sewing heavier and thicker . I put a heavier tension spring and new disks on it, with also using a Thread Post w/ tiny tension disk .
'interesting'.. So yours might have been MacGyver'ed even better approach, with that added tension setup put on it . Sew with it and let me know if that works well, I very well could be adding that to mine .
.

[cybernob]

I'm thinking of altering mine with a Juki tension set like this one as it has the visual cues for p[ositioning, the one that came with it one of the tensioners is coming out from the press seating .

 

Will let you know how it goes.

[nylonRigging]

20 hours ago, cybernob said:

Will let you know how it goes.

Well string it up, sew and see, figure out what he was doing ? . it;s interesting, he had something in-mind for taking an interest with doing that setup . looks like he is still keeping/using the the knee press-foot lift with factory tension unit . Did you ask previous owner what size thread he was trying to run on the top thread ?

Did you ask previous owner what size thread he was trying to run on the top thread ? . was he trying to use 138 on top ? . I have very similar looking DB body , but I did not have to add that much extra tension on the machine to punch thicker and heavier, and to make good looking stitches top bottom . but I only using nylon #69 . The L-bobbins in my DB are pretty small but OK volume for using #69, but L-size is small and a lot of bobbin changing when sewing .

.

Edited March 28, 2021 by nylonRigging

[cybernob]

10 hours ago, nylonRigging said:

Did you ask previous owner what size thread he was trying to run on the top thread ?

When he showed me he was using 69 as well and how it was threaded through the additional tensioner, still passed thru the original tensioner. He told me he used it to sew heavy marine vinyl for his boat and showed me how it sews thru 5 layers. Although the needle he was using was a 180 so I suspect you are right about 138. He told me he bought a walking foot machine so was selling this one. My guess is the DB did almost everything but made the mod and it didn't work.

I've threaded it using the additional tensioner rig and thru the original tensioner as he showed me but I can't see adjusting the tension on the additional making any difference to tension result at all. The balance isn't affected. Only thing that affects it is the original tensioner, I suspect this is because of the tension spring at the end of the additional tensioner and before the original tensioner is buffering the thread so there is no constant tension.

It may be there is no difference also because I only been testing on s single layer of vinyl and it doesn't need more tension which I suspect he was looking for the additional tensioner to provide. I think he had the right idea to spread the tension out but needs to bypass additional tension spring.

From what I can see using his setup there is no real fine grained control on the tension and therefore stitch balance.

So what I'm thinking of doing is bypassing the original tension spring and putting an adapter plate that will allow the foot lever to still operate the tension of the additional tension set. It means I can remove it no harm done. Crazy? But if it works I think it'll work really nice and give me a larger tension range. I've got some 138 here and will try it out as well probably on the weekend as I've removed the additional tension set to look at how to make the adapter plate and also I have to reseat the press fitting on it.

[chrisash]

Testing any machine on a single layer is a pointless test as you will always be sewing either two or more layers. No doubt the tension setup he has works, just try wit two or three layers of what you intend to sew and the thread you want to use both top and bottom and start testing in the real world

If the bobbin drops down when you shake the thread slightly when holding the thread above it with the bobbin off the floor then thats about right for the bobbin tension, then depending if the knot is either above or below the surface of the leather when you sew make adjustment's to the top tension to get the know between the layers

Edited March 29, 2021 by chrisash

[DonInReno]

The previous owner just rigged up a tension unit he had on hand, or didnt know what he was doing - there’s no reason for a second tensioner on a single needle machine.   
 

I think your money is better spent saving for a walking foot machine and don’t sink anything new into this one - that’s also exactly what the previous owner thought as well.    Having said that, parts are cheap and if it’s fun for you who’s to say otherwise :-)

[cybernob]

22 hours ago, DonInReno said:

I think your money is better spent saving for a walking foot machine and don’t sink anything new into this one

Thanks for the advice as you said they're cheap so I've got the missing thread guide coming to put it back to normal. I'll still experiment with the second tensioner as I have it just to learn more :). When I get more serious though I'll get a walking foot.

[JCL]

I have a Mitsubishi electric DB-121 industrial sewing machine, like the one being discussed, that I would like to sell. 

As mentioned in the original post, I am unable to find much information about it so I'm hoping that someone can help me with information about this like how much are they worth, how old is it, where could I find a user manual, what is it used for, and is there an online platform where I could sell this? It's been sitting in my dad's garage for a while and needs a service which would need to be factored in to the price. 

Any information would be greatly appreciated. TIA

- Jessica 

[Quade]

These kind of machines aren't worth all that much money.  I got my Juki DDL-5550 for nothing on craigslist (which is in the same class as this machine). Literally nothing.  I just had to haul it away.  If it has a table and servo motor, I might start at $500 and be willing to drop the price if you get no bites.  If it's got an old clutch type motor (big heavy cast iron thing), I might start it at $300.   The table, if it as one, might be worth more than the machine itself. 

The problem with these machines is that they're pushing 300lbs total weight if they have a clutch motor.  That makes shipping problematic. The sewiing head itself weights 80 or so lbs. 

I'd just throw it on facebook market place and craigslist.  Most people don't assume you'll ship it on those sites. 

[Burkhardt]

14 hours ago, Quade said:

These kind of machines aren't worth all that much money.  I got my Juki DDL-5550 for nothing on craigslist (which is in the same class as this machine). Literally nothing.  I just had to haul it away.  If it has a table and servo motor, I might start at $500 and be willing to drop the price if you get no bites.  If it's got an old clutch type motor (big heavy cast iron thing), I might start it at $300.   The table, if it as one, might be worth more than the machine itself. 

The problem with these machines is that they're pushing 300lbs total weight if they have a clutch motor.  That makes shipping problematic. The sewiing head itself weights 80 or so lbs. 

I'd just throw it on facebook market place and craigslist.  Most people don't assume you'll ship it on those sites. 

Did you notice she's down under? Guessing the market could be different.

[Quade]

Could be no doubt.   I'd still suggest it's not a particularly desirable machine. You can buy a brand new juki in this class with table and servo for under $1000 US. 

https://www.amazon.com/Juki-DDL-8100-Lockstitch-1-Needle-DDL8100e/dp/B07Q5NHZCP/