PDA

View Full Version : Sieg C4 lathe



ion
09-15-2014, 02:39 PM
Hello,

A few months ago i was finally able to build a small work shop where i'm trying to learn and experiment with metal working. I think i got addicted to this. I spend so much money on tools and machinery but of course, being limited by the space i have, pretty much everything i buy is hobby machinery.
I started metal working with a Sieg C1 lathe which was very good but too small for my needs and recently managed to buy a Sieg C4 with a 550 mm bed.
I really love this lathe but there is one thing that really bothers me: the noise.
The noise is awful.
My knowledge about lathes and mills is very limited right now but the noise this lathe makes doesn't sounds right to me. It doesn't have to be as quiet as the C1 lathe i had but the noise/sound should be bearable.

If i try to run it at over 660 RPM it sounds really loud so i never use it at more than 650-660 RPM.
I found the Bob Ackert's SIEG SC4 Manual and did all the cleaning and oiling of the machine.

I tried to find more information on the internet but it looks like there is not many people posting anything about this lathe.
I wonder if there is a clone of this lathe under a different name. I could use the information for improving and future mods of this lathe.

So my question is what should i do to make it less noisy? How should i troubleshoot the source of the noise?
Any help is really appreciated.

Another question is regarding the cross slide. In most of the videos i found on internet, the cross slide is positioned at an angle. I have mine parallel to the bed.
Should i position it angled? Is the angle important?

Does anyone have a DRO installed on this type of lathe?
I'm thinking on installing the Igaging magnetic scales. In case anyone is using the Igaging scales, do you know what scale size should i order?

I installed the Sieg made digital scales, the ones that count the hand wheel rotations and they are really hard to use because of the backlash.

Does anyone have any experience with the tailstock turret on a lathe like this? Is it worth the money? Are they accurate?


Any mods and tweaks that i could use on this lathe?

Thank you very much.

lynnl
09-15-2014, 07:17 PM
Hello,



Another question is regarding the cross slide. In most of the videos i found on internet, the cross slide is positioned at an angle. I have mine parallel to the bed.
Should i position it angled? Is the angle important?



I think what you're describing is the top slide, or compound slide. The cross slide is made to be at 90 degrees to the bed, with no provision for varying the angle. The top, or compound, slide is the item that's adjustable. Just set it at whatever angle is most convenient for the task at hand.

Most often people will set it to something like 30 deg., but there's nothing sacred about that, other than for thread cutting.
One can, by setting it to the proper shallow angle, advance the feed by tenths when the dial reading is in thousandths. I don't remember offhand what that angle is, but a little trig work will reveal it to you.

Also there are times when a tapered cut is called for; angling that top slide is done for that purpose.

As for the noise, I can't help you much, having never seen that lathe. But you might try to describe the noise to help others maybe troubleshoot the problem. You make it sound totally unbearable. Is it a metallic or grinding or rattling or screeching or banging, or what?

tmarks11
09-15-2014, 08:13 PM
really love this lathe but there is one thing that really bothers me: the noise.
The noise is awful.
Open the end cover where the belt is, and take a look at the pulleys. Make sure that none of the keys that hold the pulleys in position on the shaft has slipped out and is rubbing on anything (I had that happen, different model import lathe, caught it before impact occurred). Check that none of the nuts holding the gears is overly loose, allowing the gears to wander or grind.

http://www.mini-lathe.com/m4/C4/gt01.jpg

Take belt off and run the motor by itself. Still make noise?

http://www.mini-lathe.com/m4/C4/tcs03.jpg

Take off the A gear (above, has a nut holding it in place), which drives the gear train from the spindle, put the belt back on and run it again. This disconnects the QCTP from the spindle. Still make a noise? Now you can tell if the problem is the spindle bearings or something in the QCTP.

It shouldn't be making a horrible noise. Something is very wrong.

Credit: photos from mini-lathe.com.

http://www.mini-lathe.com/m4/C4/c4.htm

ikdor
09-16-2014, 04:24 AM
I think I have a Sieg rebrand and the change gears make a lot of noise. I keep them disengaged when I don't need them for noise reasons.
Igor

ion
09-16-2014, 05:33 AM
lynnl thank you very much, it was the compound slide that i thought it's called the cross slide. Sorry for the mistake. Now i know.

tmarks11 I did as you explained, and the noise definitely comes from the spindle, probably the bearings.

I disengaged the spindle and the noise was what you would expect from a normal working lathe. As soon as engaged the spindle the sound is very sharp.
Here is a video. It starts with the spindle disengaged and then i engage the spindle:


http://youtu.be/1T7IX7Gsp8U

ikdor on sieg c4 there is no gear change. The speed is controlled electrically.


The question is: What would be the next step to be able to lower the noise? Is there anything that i can do?
Probably replacing the bearings but i don't have a press for that, is there a easy way? :)

RichR
09-16-2014, 07:58 AM
Hi ion
That sounds like the gears to my untrained ears. Easy enough to figure out. Disengage the gear. Chuck up a piece of 3/8" rod. Chuck the other end into a
variable speed drill and slowly run it up to speed. If it's still noisy, it's probably the bearings. Take care when doing this as the lathe chuck could have
considerable momentum while spinning.

tmarks11
09-16-2014, 09:43 PM
ikdor on sieg c4 there is no gear change. The speed is controlled electrically.
"Change Gears" refer to the gear train that drives the lead screw for feed & threading.

There are some lathes with a "electronic leads crew", which uses an independently controlled servo motor to drive the leads crew. Sieg SC4 would not be one of those lathes (just the servo costs more than the SC4).

The change gears set is the gears I showed in the picture above. Some of them are made to come off (they have hex nuts on them). You should also wipe way oil (Mobil Vacta 2) on them; that will help quiet them.

Stop me if I am telling you something you already know...

If you take Gear A off, it will stop the gear train from being driven by the spindle, and that will help you ensure that the noise comes from the spindle.

If your spindle is noisy, a few possibilities:
1. The bearing followers are too lose. You can check this by putting a Dial Test Indicator on the end of the spindle, and apply pressure to the spindle by hand and see if you can shift it. Or run the DTI on the indies of the spindle (with no chuck installed) and see how much runout (or wobble exists).
2. The bearings are too tight. This would be noticed by noise and a lot of heat after a short run. The bearings should get hot with use, but the spindle should never get hot enough to burn you.
3. Casting sand and debris in the bearings. A common problem, since apparently china gets paid by the pound for their products, and believes the rest of the world wants to pay them for their sand as well as their cast iron. Harder to diagnose; if you disconnect the gear train and remove the belt and turn the spindle by hand, you might be able to feel if it is not smooth. Maybe listen to the bearings with a stethoscope.

oldtiffie
09-17-2014, 12:40 AM
I am curious as to whether the OP's Sieg lathe was bought new from a credible provider (who would exchange it if needs be) or from the net with no warranty.

So far it seems to be more the latter than the former case.

ion
09-17-2014, 01:36 AM
tmarks11: thank you for the explanation. I will try to follow your recommendation. I already oiled everything and cleaned the casting sand. I'll try to change the gears and see what happens.

oldtiffie: I bought the lathe from an official sieg provider. The lathe is new but I suppose you need some experience to deal with these lathes before you buy them so you can fix and tune stuff on them.

I noticed that if I put the lathe to run in reverse the noise sounds a lot better.

wheeltapper
09-17-2014, 05:45 AM
I have the same lathe and the gears you show are noisy.
I use chainsaw oil on them, nice and sticky and they run a lot quieter.

Roy.

wierdscience
09-17-2014, 01:52 PM
In the video when you grab and rock the gear back and forth it sounds to me like the gear is moving on the shaft and knocking on the key.Maybe mark it where the gear and shaft interface to see if it is moving.

The rest just sounds like gear noise,probably due to them being new and not broken in yet.There is a lapping compound that can be applied to speed up the process by polishing the contact areas on the teeth.It's pricey though $70/can,it's the Timesaver green label one listed here-

http://www.newmantools.com/lapping/time.htm

ion
09-17-2014, 04:23 PM
I checked the gears. The teeth are very rough and the edges are sharp. They definitely add to the noise. That lapping compound sounds interesting but it's too pricey to me and i don't know how much is going to help.

I disengaged the gear A as tmarks11 suggested, the noise is pretty much unchanged so the most of the noise comes from the spindle.
As i said, when i run the machine in reverse the sound is not that bad.

Probably it's not a good idea for me to tinker with the spindle just yet not knowing exactly what i'm doing.

Richard P Wilson
09-18-2014, 05:34 AM
I checked the gears. The teeth are very rough and the edges are sharp. They definitely add to the noise. That lapping compound sounds interesting but it's too pricey to me and i don't know how much is going to help.

I disengaged the gear A as tmarks11 suggested, the noise is pretty much unchanged so the most of the noise comes from the spindle.
As i said, when i run the machine in reverse the sound is not that bad.

Probably it's not a good idea for me to tinker with the spindle just yet not knowing exactly what i'm doing.

I listened to your video, and to be honest its around the noise level I'd expect from a lathe of that class with straight cut steel gear drive, especially if you say the gears are a bit rough. If you don't want to take it back where you got it from, my advice is just put the top cover back on and use the thing. If you want a quiet lathe then its got to be belt drive.

ion
09-18-2014, 10:38 AM
Thank you for advice. I can only compare the sound to my previous lathe that was a lot smaller. I never saw any other lathe and that's why I thought it's too loud. I will just use it as it is, oil it down and tighten the screws.
As a matter of fact today I applied some chain saw oil, and changed the gears with some gears that didn't looked that rough. I'll see how it sounds after the gears get smoother.

wheeltapper
09-18-2014, 05:37 PM
To be honest, the two gears under that cover, at least on mine, are complete rubbish.
the're like two bicycle sprockets!
it's no wonder they are noisy.

mine aren't too bad now they have run in.
pity it's taken four years.:(