Cecilia S.

Hi Group,

Remember my lovely Phoenix 429? I named him Ziggy. He is looking very handsome now; I gave him a nose job. Shall I post photos?

I purchased a new belt for him, and now that I have it, I just want to verify a few things. I posted about this before I bought the belt, but now things are actually -less- clear to me. Here is why:

I brought in the old belt, and OSMG sold me a new one just like it, except sizewise, it fits inside the old one! He said that the old one would have originally been this size, and had stretched over time. I believe him there, for the old one was indeed decades old, cracked, etc. The new one's outside diameter and circumference pretty much match exactly the old one's inside diameter and circumference!

(Yes, Joe, these are both the rubbery noodle type belts; he said he would have to see the machine in order to sell me the proper sized V-belt. Anyhow, at $3.49, it is all a learning experience for me! When I get smarter about belt size etc, I will certainly try the v-belts which you recommended as being superior.)

OSMG said to put the new belt on, and not to change the position of the motor to accomodate its smaller size. I am concerned about this, because there will be -such- a difference in snugness, and I realize that a too-snug belt can put extra strain on the motor shaft and wreck things.

I understand the concept of raising or lowering the motor so as to create "just enough grab so that the belt does not slip." However, I would think this criteria would be quite different depending upon whether I would test with sheer cotton or with leather.

Can anyone offer a more fool-proof way of my setting the motor height so as to bring the belt to a suitable tension? I think this must be something that the Experts get a feel for over time; the feel of the deflection of the belt when pressed lightly with fingers, for example. Is there anything definitive that any Expert can tell me about the deflection, such as, "On a properly set belt, When I suspend a 100 g bag of almonds from the belt, the belt deflects XX inch from its original line."

That is just an idea, but if there is a more straightforward way of explaining it to me, I would be so appreciative! I am fearful of doing something which may over time damage the motor.

Thank you in advance.

J Miller

Cecilia,

I have found that the cogged belts need to be a wee bit tighter than the black V-belts to not slip. I think the plastic they are made from is slicker than the black belts. Also make sure the motor pulley and hand wheel belt grove is clean and free from oil or old belt residue.
I just converted my ALDENS Magic ZZ from a non-adjustable motor that required a rubber band belt, to an adjustable motor and put an amber cogged belt on it. It slipped like mad until I removed the belt and used some 600grit sand paper to clean the crud out of the motor pulley. Now it works OK.

I have never had a cogged belt stretch like what your LSMG said, a little yes, but not that much. I don't think there is any way you're going to get the new belt on without adjusting the motor for it. I wouldn't worry about moving the motor, that's why there is an adjustment to it.

Joe

Cecilia S.

The belt I have is like a fat round black noodle, not a beigey one with toothy cogs.

The info you gave is helpful Joe - esp about making sure things are squeaky clean.

Still if anyone has any specific guidance as to how-to-gauge-the-snugness, I would be very appreciative.

-C

mlmack

http://blog.sew-classic.com/2010/02/...hine-belt.aspx

The stretchy ones are harder to judge because they stretch. I would loosen up the motor bracket, install the belt, and just make sure the belt is just tight enough to turn the motor and balance wheel without slipping.

J Miller

What Mark said plus I'd get a proper V-Belt for it as soon as you can. Those rubber band or noodle belts don't last as log as the real belts and they do tend to slip.

Joe

Cecilia S.

Mark and Joe, Thanks again for your time.

I do understand the idea of "just enough so it does not slip", but that concept is what prompted this thread in the first place. Is there anything quantifiable that you can tell me about how tight that is? Slip... while simply turning the handwheel? Slip, while sewing leather? Slip, while sewing thin crepe? I really have no idea! Sorry!

Also Joe, how would I know the correct size v-belt to get? OSMG said he could only know by seeing the machine, which seems a bit silly to me. At 44 pounds, I am not bringing the machine to him! ;-) Are there any measurements I can take, or standards to know about, so that I can buy a suitable v-belt without the vendor seeing the machine?

Many many thanks,

-C.

miriam

I would pay the OSMG to show me how (if he is willing) and you don't know.
The above link to Sew classic has good info on belts.

Cecilia S.

Good idea Miriam. I might try another OSMG. This one was very sweet and amusing (and even asked me if I wanted to take over his shop, since he wants to retire...) but he was totally blase about the belt tension thing despite my trying to ask politely for a definitive answer. I didn't want to pester or push him on it. But you are right, it is really probably something one has to learn by feel.

(Though I still think hanging 100g of almonds and measuring deflection might be a good starting point... ;-) Or cherries? Then later we could sow the cherries?)

mlmack

Take the belt off, and loosen the motor bracket so that the bolt that holds it to the machine is in the center of the long slot of the bracket, then tighten the bolt.

Then, grab a piece of string, and wrap it around the motor pulley and the hand wheel pulley, and mark where the end of the string meets the rest of the string. Measure that distance, and it will give you a good approximation of how long the belt needs to be.

Your belt tension should be the same whether you are sewing thin or thick material.

When I put on a new belt, I loosen the motor bracket and put the new belt on, and just let the weight of the motor pull the belt taut, and then I tighten the motor bracket bolt, which often tightens the belt a little. Then I run the machine and do some test sewing, and if the machine slips, I tighten the belt a little.

J Miller

Mark covered it. Sew-Classic has those same instructions in print.

As for your OSMG he simply cannot pull a belt size out of the air. There is literally hundreds of brands of machines and far more sizes of hand wheels and motor pulleys. I asked my LSMG and he told me there is no concise belt listing for sewing machines like there is for cars.

Take the machine to him and have him fit it with a proper belt. Then record the belt number and the next time you'll have it.



Joe