Some questions about my new (used) Uni......................

[Mark Rios]

A couple of months ago I bought a 4 year old Unisaw from a firefighter who hadn't used it in a couple of years. (Thanks to all who helped me with this purchase.) He had a number of WWing tools of which all but one were Delta. This saw turned out to be a "Limited Edition Unisaw with 50" Biesemeyer Fence System", according the the name on the manual. I previously had used a Ridgid contractor saw (which is currently for sale in the Swap and Sell forum).

I finally got it put together, run the 220V circuit, made the ext.cord and have been using it for a couple of weeks now. WHAT A BIG DIFFERENCE! I'm sure that you folks are saying "Well DUH!!!" but this is my first time using a cabinet saw. Whereas I didn't really have any trouble with the 1 1/2 HP motor on the Ridgid as far as bogging down, I can really tell that this 3HP motor is doing it's job. It's also sooooooooooooooo nice not having to bump the trunions with a precision block of wood to adjust the alignment like on the contractor saw. Another very nice thing is that I no longer have a big pile of sawdust to clean out from the upper cabinet area, from in and around the legs and from off of the floor. At the end of the day I just stick the hose from my shop vac into the DC hole and suck out the sawdust. It's like magic. (For those that don't know, my saw lives in my big work trailer with some other tools and my shop is in the backyard of the three unit rental property that I manage (and remodeled and sold). Thus, no DC.)

I do have a couple of questions though, if you would be so kind:

1) Why is/was this a "Limited Edition"? The model is 36-843. It isn't an X5 or anything like that (that I know of anyway) and I can't really tell any difference from the pics of any other Uni's. Anyone got any ideas? Again, it's vintage is from about four years ago.

2) When I got the saw, the belts had not been adjusted really. There was quite a bit of slack in them. They had also, I'm assuming, taken a set from not being used for a couple of years. I didn't want to go through the trouble of tracking down new belts for this right now so, while setting it up, I left the middle belt where it was, moved the right belt a quarter turn forward and the left belt (arbitrary right and left, I know) a quarter turn backward. I did this to try to eliminate the set (what do I know?). I have tensioned them appropriately.

Now, on start up the saw starts up with a bang. If I've been using it, shut it off and then turn it on again in about a minute or two, the bang is greatly reduced or even gone sometimes. However, if it sits for awhile or overnight and then use it, it bangs again.

Is this because of the belts even though I turned/staggered them as above? Is this a really bad thing for the saw?

3) I had used ZCI's on my Ridgid and I'm using a couple of them on my Uni. However, there is a tremendously reduced amount of sawdust that is thrown up onto the top of this saw compared to the Ridgid. A suprisingly small amount. Anyone have any ideas why this might be? (This, of course, is a very positive thing. I'm just wondering why the difference.)


Thanks very much for your insight and advice.

[Allen Bookout]

I bought my first Unisaw last year so I am no expert but here is my understanding of the whole situation. From what I could find out, including talking to Delta in Miss., is that Unisaws are Unisaws. About the only difference is when they were built and what promotion was coming along at the time and what motor was being used at that time and where some of the components were manufactured. This includes the X series with the extra promotions.

My Uni always starts up with a bit of a bang. The first few times it kind of startled me but I guess that I just got used to it. A lot of mass to go from 0 to 200 in seconds. I am running the factory belts. It is interesting that your bang decreases when started after running for a while. I think that mine is always about the same so I have no idea there. Could also be that we are not talking about the same amount of bang. It will be interesting to see what others have to say.

Allen

PS I just went out and started mine up a few times and there was not much of a bang - almost none. I had been using it earlier in the day so maybe your situation is normal. I need to pay more attention.

[Jim Becker]

"Limited Edition" was likely made to compete with similar promotions from Jet a number of years ago. My Jet LT Cabinet Saw, for example, is labeled "Anniversary Edition". In fact, Delta even matched the ivory color on one of those marketing deals. Same UniSaw...different paint. That's it.

As to the "bang"...I had it on the Jet, too, with the original belts. It went away when I switched to link belts. Smooth as silk...as the link belts don't "take a set". I just had to retension them about a month after first installation to take out the little bit of stretch they got in that time period and haven't touched them since...which is about 6 years now.

[Bruce Page]

Mark, I have a “Grand Edition” (ivory color which I like ) w/50” Biesemeyer. As Allan & Jim mentioned, it was a package promotion deal. I adjusted the belts after a couple of months of use and haven't had to touch them since. Thankfully, my Uni has never had the bang problem but the posts that I have read on it always point to the belts as being the culprit. As far as it not throwing large amounts of sawdust up on the table, the Uni has a nice dust guard around the blade.

[Bill Lewis]

My X5 also starts with a bang. I figured I would eventually get around to doing what Jim did i.e. Link Belts, or look for a good automotive belt (harder to find these days) that would work.

[Harley Lewis]

Well fellas, I have a bit of a different take on the belts. One, the belts on the uni are industrial and not automotive so if you decide to change make sure you use industrial belts because automotive belts have different pully angles. Most of all I have read is that link belts are not a good idea with a uni and the three belt system, hard to get three the same length and those who know more that me can tell you other reasons. Last, it takes time for a belt to break in -- run the saw for a half hour or so and the bang will go away after the belts seat in the pulleys and heat up some because of friction.

I also have the limited addition saw, and the only differences are paint color, ht and tilt wheels are a bit different, and it has a personalized name plate. It was a marketing ploy to sell saws at that time.

Harley

[Stan Krupowies]

Most of all I have read is that link belts are not a good idea with a uni and the three belt system, hard to get three the same length and those who know more that me can tell you other reasons.

Harley

I'd have to agree with that statement about getting the same length from 3 link belts. I put three on my Uni and while two of the three are fairly tight, the third is noticeably looser. All three have the same number of links and all were bought from the same store at the same time.

I also have the 'bang problem' with my saw. I bought it new from Amazon in April. It banged with the original belts and it did bang slightly less with the link belts. It routinely fails the nickel test on start-up. I do notice that David Thiel's Uni on Tools & Techniques starts very smoothly. Perhaps I should call Delta and see what they have to say.

[CPeter James]

I have a PM66 and have found that belt tension and the bang on my saw are related. I tried dirrerent belt tensions and finally got it quieted down and it is better for now. I think the problem comes from the very short belts not having much give at startup. The belts on my PM66 are so short that they are special made by Goodyear, but only available from PM.

CPeter

[Chuck Saunders]

The belt issue has been well discussed with the key point being that the 3 belts are Matched belts not just 3 marked the same size. The bang is more from tension than belt set. If you are not getting alot of vibration then belt set is not a big problem.

The lack of sawdust on the table surface is a function of having a bigger air chamber below and the "prevailing winds" are dissipated.

I have been very happy with my unisaw and it keeps me from schemeing to get a PM72 for home.
Chuck

[JayStPeter]

Sounds like the same saw I have.

1) Limited edition was a special package that included the (at the time optional) motor cover, dust chute and mobile base.

2) Proper tension is pretty loose, you probably overtensioned the belts and brought up the bang. My original belts had taken a set before I ever used the saw. Delta replaced them and all has been well since.

3) I don't notice the same.

[Curt Harms]

"Limited Edition" was likely made to compete with similar promotions from Jet a number of years ago. My Jet LT Cabinet Saw, for example, is labeled "Anniversary Edition". In fact, Delta even matched the ivory color on one of those marketing deals. Same UniSaw...different paint. That's it.

As to the "bang"...I had it on the Jet, too, with the original belts. It went away when I switched to link belts. Smooth as silk...as the link belts don't "take a set". I just had to retension them about a month after first installation to take out the little bit of stretch they got in that time period and haven't touched them since...which is about 6 years now.

I did the same thing with the link belts on a G1023 before I'd heard it wasn't a good idea . No "bang" on startup. I've never ripped 2"+ hard wood with it so I don't know if the link belts would be prone to slipping or not. I also don't have the belts all that tight. I have read that 3 belts is way overkill for 3 H.P. so they don't need to be all that tight. If I were to do it over again. I might consider 3 "cogged" belts if I could find the proper type. I've heard they don't take a set either.

[Bob Reeve]

Sometimes I cannot keep by big mouth shut. Hopefully this will be a time that does no harm.

I work for one of the top 2 manufacturers of industrial VBelts in the world for quality. Here is what I know after almost 30 years.

Link Belts were designed to be an emergency replacement and not for ongoing use. You cannot get equal tension across 3 of these belts as the length tolerance is too great. If a machine is designed to run 3 belts then it needs three belts to function at peak loads.

Cogged belts were designed to work over smaller pulleys. Because they are raw edged they grip better but are noisier and wear out the sheaves quicker. They also induce more vibration.

Belt matching is a thing of the past as all major manufacturers have gone to a matchless system.

If you stay with a major manufacturer such as Optibelt, Gates, or Goodyear, you will not have a length problem. Belts made in China, Japan, and Taiwan are NOT equal at all to the belts made in the US or in Germany.

It is critical for vibration that you have the sheaves coplaner (aligned) and that you have proper tension. Just pushing at the belt with a finger does not give you proper tension. Check with the machine mfg or belt mfg. for correct tension.

Sorry to ramble so much.

Bob

[Mark Rios]

Thanks to all very much for all your help and advice. You've answered my original questions and a few more.

However, Bob has brought up another one that perhaps he can help us with.

Bob, while I appreciate you vagueness regarding your employment, would you be able to go into more detail about the proper tensioning of belts for us (or at least for me )?

There has been a number of threads discussing the tensioning of bandsaw blades but never one that I can remember concerning belts. I would value your input and I think it would be a benefit to the membership as well.

Thanks very much again.

[Allen Bookout]

Sorry to ramble so much.

Bob

Ramble------I should say not. Straight to the point.

Always good to hear from an expert.

Allen

[Jim Becker]

I've ripped thick stock with zero issue using the link belts. No loss of power. No clue if one isn't the same length. It just cuts!