Gritzner Frobana Feed dog issues

[alexitbe]

Feed-dog height issues...  After reading the manual(thanks Jimi) the max feed dog height is 4mm and should be used for the thickest leather.

 

However, my thinnest leather setting has 4mm feed dog height, the middle 3mm FD height and the thickest setting 3.5mm.  See below.  Does anyone know how to change this?

 

I would atleast like to be able to drop the height to 1mm for the thinnest setting to limit damage to the underside of the leather

 

Here are some pics.

Thinnest setting

Middle setting

Thickest setting

 

Has anyone had any similar experience?

 

Thanks for any advice.. 

Cheers

Alex

 

 

[jimi]

i would try and follow that shaft to see what is happening? must be a cam or something on the other end??

you also have a strange looking feed dog on there, i have only seen the 2 teeth type. i dont think they made 4 but i am not sure. this is for rubber soles, the one for leather is a knife. also you can see the difference between a used one and a new one. "someone done the teeth sloping the wrong way in the old one".

Edited July 5, 2017 by jimi

[CowboyBob]

You can turn it down to the lowest setting,loosen the 2-screws on the collar, turn the pointer to mittel (making sure the shaft doesn't turn), tighten screws & turn down more.

[GPaudler]

I know nothing about these machines so my input is probably useless, but that feed dog looks hand-made and might not correspond to the factory dimensions.

 

[alexitbe]

9 hours ago, CowboyBob said:

You can turn it down to the lowest setting,loosen the 2-screws on the collar,turn the pointer to mittel(making sure the shaft doesn't turn) ,tighten screws & turn down more.

Thank Bob and everyone who has responded.

Bob: the problem is that the lowest setting is 3mm, which is still too high.  I would like to get it down to 1.5 mm.  Also, at both ends of the stitch length adjuster range (dunn(thin) and dick(thick)) it becomes very stiff.  If I simply change the pointer position so that the lowest setting (3mm) becomes the thinnest (dunn) setting and not the mittel, which it now is, I think it will reduce the range of the adjuster knob.  However, I will try what you suggest.

 

Jimi:  I will have a look for the cam, maybe it has slipped out of position.  Thin to thick setting on the stitch length adjuster should cause a steady increas in height, which currently it does. Thin is 4mm, mittel is 3 mm and thick is 3.5 mm.  Something is out of kilter...

I am going to either buy or make a new feed dog, which is a cutter.  The current feed dog, is probably for rubber and it probably is homemade.  Here in the old DDR, they become very clever at getting around shortages of goods and parts.

Thanks once again for everyone's suggestions..  It is beginning to sew properly...

Cheers

Alex

[CowboyBob]

Here's the difference I get from high to low.

 

Edited July 6, 2017 by CowboyBob

[alexitbe]

Hi Bob,

 

Thanks for taking the time to take the pictures.  The range of depth you have is just what I am looking for, so I think something must be wrong with mine...As you see from mine I only have a range of 1mm and that's in the wrong order...

 

I see you channel knife is pretty poor.  I am going to make one for myself, since I am making one, then making 2 is no more time.  I can send you that if you wish.

 

Cheers

Alex

[jimi]

Alex, you could maybe try to loosen this screw also? i think it just blocks the shaft?

if the machine is not bolted to the base you could probably see things better from underneath??

Edited July 6, 2017 by jimi

[alexitbe]

ok Jimi, I will give that a go... And  try this weekend... I am a little scared about adjusting, because it does sew already, now that the tension issue is partially sorted....  I buggered up a fur sewing machine that wasn't running quite right by fiddling and i would have been better off leaving it alone...

 

I have been trying to find a spare parts diagram, but have had no luck... That would help also to get an idea of what is connected to what and its function.....

Cheers

Alex

 

[jimi]

Oh i have one of them and they have little arms and shafts that move all over the place what make was the fur machine?

i would think it difficult to bugger up one of these frobanas as they are solid sods.do you have it bolted to that pine underneath?

[alexitbe]

Hi jimi,

 

As with most things I buy, the fur machine is an old DDR model by Textima.  One day I will sit down and work it out....

 

No the Frobana is not screwed down, so as you say that should help... I am just scared of messing up the timing and not having any marks to go back to... I should be less of a coward..:)

 

Cheers

Alex

[jimi]

yes! but take pictures before you loosen anything? can you see the shaft underneath??

[jimi]

they usually come bolted to the pine wood base and have a box lid with a key to lock. mine has this missing, but if your machine was without the base then maybe that is where it got knocked? underneath. iam almost 100% sure if you can see underneath then you will find the problem right away."yes they came on a iron stand also"

Edited July 6, 2017 by jimi

[alexitbe]

This came without a base... So you give me hope.... that there is a simple solution...

[alexitbe]

So I finally did this and I will try and explain.  As the feed dog height is rotated, the accentric also rotates. The accentric forces a horizontal  bar left and right.  This bar is angled so that the vertical feed-dog moves up and down as the horizontl bar moves left and right.  The problem seems to be that the accentric was not in the right position, so that the minimim feed-dog height was on the middle setting and not at the lowest. The turning or saddle point of the accentric ie minimum, was at the middle setting and either side of that the feet rose higher.

After adjustments I now have a feed dog height of 2.5 mm on lowest and 5 mm at highest setting.  I would like to be able to drop the whole thing down 1mm, but I have not had time to work that out.

 

Anyone have any idea B moves up and down adn what would happen if I moved the nuts?

 

Sorry if I have not explained it very well.  i simply do not know the proper terms for the parts.

Cheers

Alex

[jimi]

Hi Alex, have you checked the size of your feed dog? new the two teethed one should be 15mm total and the knife type13mm. 

[alexitbe]

Hi Jim,

I have not checked the size of the feed-dog and I guess I should do this next , since you think it is not a standard part.  I will then compare it to your measurements.

I will order a knife part next week, as I am a little pressed for time at the moment and I would like an original part. Also, I will use it for making shoes so, I need the knife so as to be the stitches well into the sole.

I am pleased that the feed-dogs are almost fixed and the shuttle tension issue has taken care of itself with thicker thread.

Cheers

Alex