Sieg SC8 and its spindle mount

joshua43214

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hopefully this is in the right place

I am considering a Sieg SC8 from DroPros
http://www.dropros.com/DRO_PROS_Sieg_SC8_Lathe.htm

This seems to be about the only alternative to the PM1030 (except the over priced BT1030A from the scary Bolton people).
It has a potentially deal breaking issue though with the spindle mount.
You can see some images of the spindle mount here
http://www.mini-lathe.com/reviews/Lathes/Sieg_C8/C8.htm
It looks a bit dodgy to me, but it might be fine.

Does any one here have any experience with this lathe?
I called DroPros and was told that the spindle mount was proprietary to Sieg. But he also told me that it had a metric lead screw (it turns out it does not), and that a metric lead screw cuts perfect Imperial threads (which is nonsense).
All they carry are Sieg 4jaw scroll chucks (which are rumored to be crap), no independent chucks. They do not carry any faceplate adaptors. I was told that they leave the little stuff like that to LMS.

So I called LMS and they have no clue what the spindle mount is, but they hope to get something together by this summer, maybe.

I could only find two reviews of the lathe online. One is on the mini-lathe.com site, and the author mostly just gushed over how massive and solid the machine is (such is the life of a mini-lathe user lol).
The other was from a guy who never bothered with the chuck and just mounted up a collet system.

I despise proprietary designs for critical parts on principle. To make matters worse, DroPros seems to be the only North American distributor of this machine, and I do not trust them to keep selling them. As it stands now, the only way to get an adaptor plate is to buy a 4jaw chuck and take the adaptor off it.

Any light on the mystery would be greatly appreciated.
-Josh
 
The SC8 spindle mount is similar to those found on most Asian import mini-lathes (which are Sieg variations also). The chuck will either have studs threaded into it or just threaded holes, and is bolted on to the backside of the spindle flange with either nuts or bolts.

I don't like these types of spindle cause they can be a pain to change chucks depending on the lathe design, especially if you have fat fingers. Most of these types of spindles don't have a nose taper for chuck registration, but not all. I don't favor spindles without a nose taper.

If you will be threading imperial threads most of the time & the SC8 is only available with a metric leadscrew, I would stay away from it. Metric lathes (metric leadscrew) can thread imperial threads that are close enough to work perfectly fine but you won't have the ability to use the thread dial "normally" (there is a method to partially use it but still).

(Moved to the Sieg section)
 
Ya, the nose does appear not have a taper, like I said looks a bit dodgy. I was hoping that maybe it had some way of centering the chuck that was not obvious.

The machine comes with either a metric or imperial lead screw. According to the manual, it has an 8tpi lead-screw, yet it threads down to 5tpi. It does not have a half-nut.

Shame about the spindle mount. No nose taper + no adaptor plates = deal breaker. This is essentially a collet lathe as it now stands.

-Josh
 
I believe the spindle mount is a DIN 55022 mount. I have the SC6 and have never had any problems with it. Ive made several backplates to fit alternative chucks without a problem.

There is a built in taper to the end of the spindle, and the backplate of the chuck locates on this taper.

Graham
 
The back plate seems pretty simple to me and the spindle mount has the benefits of a D type nose without the expense. It certainly has to be a step up from the threaded spindle found on smaller (or older) machines.

It has half nuts but the Dropros version doesn't have a threading dial which is odd, as it's on the standard C8. Perhaps an accessory that you can buy from Seig? It's a better looking lathe than the PM1030 in several ways, but less standard equipment. A better comparison would be the PM1127, but that's quite a step up in price with some extra features too.
 
I have the SC8-PRO package that I got my local sieg agent to import (he didn't even know it existed). The spindle mount is actually very nice and makes changing chucks a breeze with the cam system. I also ordered it with the 4 jaw but seig packed a self centering 4 jaw. So the agent gave me the SC6 chuck to try. It is 5mm smaller and just needed the adaptor plate to be bored out slightly to fit the SC8. Can't say I noticed a taper but if you want I can remove my chuck and check for one.

Good news is that the adaptor plate for the SC6 can be readily modified for this Lathe.

All in all I am very happy with it, a big step up from my 7x12 I had before.

The pro package comes with DRO and flood coolant but the lathe is the same.

Feel free to throw questions at me if you want more information. I was in the same boat as you - very little info out there on this Lathe. For me an old second hand machine was not a possibility as they are hard to find here in south Africa and the sieg agents are located in my town so at least I have some support.

Sent from my GT-I9505 using Tapatalk
 
Can't say I noticed a taper but if you want I can remove my chuck and check for one.

Sent from my GT-I9505 using Tapatalk

Ive just been out and measured all of my backplates and also the spindle register for a taper. There isnt one, so apologies. It is not a DIN55022. From the looks of it, its identical to 55022 apart from the taper.

Graham
 
Ya, the nose does appear not have a taper, like I said looks a bit dodgy. I was hoping that maybe it had some way of centering the chuck that was not obvious.

-Josh

There isn't a taper, but there is a register cut into the spindle that the chuck backplates locate on to center them.
 
There isn't a taper, but there is a register cut into the spindle that the chuck backplates locate on to center them.
Thank you very much for going out and looking at things.
I figured this was how it worked. Looks like the chuck just slips onto the end of the spindle and is bolted on. Should work well enough, but there will be no moving the chuck from the lathe to a fixture, then back to the lathe again. Certainly better than a screw on chuck. Simple to manufacture, and a clever mounting system, I'd still pay a bit more for a proper mounting system that was not proprietary.

I have the SC8-PRO package that I got my local sieg agent to import (he didn't even know it existed). The spindle mount is actually very nice and makes changing chucks a breeze with the cam system. I also ordered it with the 4 jaw but seig packed a self centering 4 jaw. So the agent gave me the SC6 chuck to try. It is 5mm smaller and just needed the adaptor plate to be bored out slightly to fit the SC8. Can't say I noticed a taper but if you want I can remove my chuck and check for one.

Good news is that the adaptor plate for the SC6 can be readily modified for this Lathe.

All in all I am very happy with it, a big step up from my 7x12 I had before.

The pro package comes with DRO and flood coolant but the lathe is the same.

This is excellent news. I am pretty sure that LMS carries an adaptor for the SC6.

I am tempted by this lathe, but something inside me is warning me off.
I wish I could put my finger on the problem.
 
Thank you very much for going out and looking at things.
I figured this was how it worked. Looks like the chuck just slips onto the end of the spindle and is bolted on. Should work well enough, but there will be no moving the chuck from the lathe to a fixture, then back to the lathe again. Certainly better than a screw on chuck. Simple to manufacture, and a clever mounting system, I'd still pay a bit more for a proper mounting system that was not proprietary.



This is excellent news. I am pretty sure that LMS carries an adaptor for the SC6.

I am tempted by this lathe, but something inside me is warning me off.
I wish I could put my finger on the problem.

Ok this is the negatives of this Lathe:

1. The speed controller will not allow you to adjust the speed until the spindle is running. It would be nice to push the arrows to dial in a speed then hit start.

2. I don't like the push button speed controls, I preferred the mini lathes dial add it was quicker to change speeds especially when threading with the half nuts locked.


3. Minimum speed is 100 rpm it would be nice if I could get this lower. I guess a smaller pully on the motor would help here.

4. Tail stock travel is somewhat short.

As you can see there are no major shortcomings, just small things that can be overcome. For the price it is a very nice lathe.

Sent from my GT-I9505 using Tapatalk
 
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