CB4500 reverse stitch bottom loops

[Zandeosaddles]

the settings I changed according to the manual caused the shuttle to not come into timing with needle at all regardless of what I do. so I am a bit lost. I need to have a sequence of what to set first in order to get the whole machine to ideal settings. The eccenrric cam at the back of the machine seems to affect the degree to which the shuttle and needle strokes and cycles function. Any advice is helpful. I am willing to execute technical instructions step by step. My machine is now totally dysfunctional. Eish!

[garypl]

Download Irfanview - a free, simple to use photo editing program.  Open your pictures in Irfanview, then select Resize in edit menu.   640 x 480 or 1280 x 960 pixels will work.

[CowboyBob]

47 minutes ago, Zandeosaddles said:

the settings I changed according to the manual caused the shuttle to not come into timing with needle at all regardless of what I do. so I am a bit lost. I need to have a sequence of what to set first in order to get the whole machine to ideal settings. The eccenrric cam at the back of the machine seems to affect the degree to which the shuttle and needle strokes and cycles function. Any advice is helpful. I am willing to execute technical instructions step by step. My machine is now totally dysfunctional. Eish!

I hope you can understand this,i'll try to explain this the best I can.The cam on the top shaft for the shuttle timing needs to be adjusted so that when you turn the machine & the needle bar is all the way down the shuttle is all the way back & coming forward just as the needle bar is coming up.Now when you do this you need to run the needle bar all the way down & watch it come up & then turn it backwards so that when the needle bar is all the way down & you turn the handwheel 2" either way it stars to come forward a the same position when the bar is all the way down.It helps to put the stitch length on 0.

[Zandeosaddles]

Thanks dor the photo advice Garypl

Cowboybob. Thanks. I do understand what must happen but im a bit in the dark as to the way to do it considering the settings given by the engineers manual did not result in the needle bar to shuttle relationship beimg right. Should I just experiment until I get it?

[Zandeosaddles]

Here are the parts in question. I dont know where to set the eccentric cam in relation to the mark on the shaft. Also the position of the large collar on the left. Is there not a guide for this eg when the cam is all the way pointing to the back?

[RockyAussie]

Here is another manual that I think someone said was easier to understand and it may help to cross reference with the other perhaps.It is a pdf file 

  .inst-441.pdf

[Zandeosaddles]

I will definitely check it in the morning. Crunch time now. Thanks for sharing.

[CowboyBob]

Ok,so the only cam to adjust for the hook is the one on the left that takes a 6mm.IF it isn't correct you turn it one way & will notice it'll get closer or further away from the way it's supposed to be.

 

 

 

[mikesc]

IF it isn't correct you turn it one way & will notice it'll get closer or further away from the way it's supposed to be.

Heh..I'm after thinkin that you'd maybe be having some Irish in yer ancestry there Bob so you might..:)

[Zandeosaddles]

On 2017-6-1 at 1:26 AM, RockyAussie said:

Excellent video as always Ewe. I found a video that I initially used to time mine and still had problems with missed stitches in reverse etc and when I followed the Juki guide as best I could it then went perfect. There was a large difference in the 2 different procedures as to where the hook ended up in relation to the needle height. The 25.9 height from the bottom of needle bar clamp and the throat plate seems a bit difficult (ha ha) but I rested a short ruler on the throat plate and got as close as I could see and now no problems. I believe that your hook is not going back as far as mine is Uwe and that may make the hook not fall back with gravity to open as easily at slow speed as is desirable. Logically a machine moving at some speed will make the hook throw back away more definitely as it reaches the end of its travel in either direction and is probably one of the reasons that miss stitches happen more when you are going slow. You'd think they would be able to work out some sort of alternating repulsing magnet to better force the opening on the hook. I should perhaps mention that I do not have any problems getting the reverse stitch lining up into the previous holes as it seems many do and I have not got any washers and so on to do this. Don't know why and if it develops I will have to find out I guess. Brian

Brian the guide seems to cover some areas better than the others. I want to ask. Should I loosen the lower timing adjustment screw as well when setting the eccentric cam. also Is it the eccentric cam which determines the relationship between needle bar height and hook position?