My "NEW" Prazi SD400 Lathe build

RaisedByWolves

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2nd one for me.

I found this offered on FBMP for a rather high price and the seller claimed it was new. It certainly looked good in pics, but at 2K it was much too expensive even if it was new. I haggled with the seller over this for more than a month and had it in my head I was maxed out at $1100.

After 6 weeks the seller gradually dropped the price down to $1400, but told me in a PM he would take $1200. Being afraid to lose it as it was now in line with offerings from PM and LMS, I jumped on it. Knowing the quality, both in manufacturing and design I couldn't resist the opportunity to have a brand new lathe to build out into what I had planned on for the first SD400 I bought.

A clean slate so to speak.


And other than some shelf wear, this machine is indeed brand new. Never made one chip as hard as that is to believe.


Here it is next to its little brother the day I got it home. I initially thought the brown on the compound was rust, but it was only WD40 mixed with sawdust.



img_4512-jpeg.499761





Little staining from the WD40 is all there was after a wipe down.

Doesn't look as bad in person, the camera picks up every bit of color.


img_4520-jpeg.499768





There are no chips or signs of use anywhere. The brown spots are WD and sawdust.



img_4519-jpeg.499767


img_4516-jpeg.499765




The flaking on the ways is still pristine. This is before it was even wiped down, the entire bed is pristine.


img_4515-jpeg.499764





My plans so far are are for a Custom Crafter motor and controller upgrade, tailstock thrust bearing and upgraded handwheel and an electronic lead screw kit. Im not sure what ELS kit Im going to use as of yet. The one that Clough uses dosent inspire me, but this guys kit looks promising.





So, first things first. Im kinda back on a budget after putting out the money for this so I have to work at the lower cost upgrades first. No big deal as the first modification Ill be making is similar to one that made a huge improvement on my SD300, radial and thrust bearings in the tailstock. But with this lathe I decided to upgrade the tailstock handwheel to a larger, heavier (10-12 times the mass of factory handwheel) cast iron handwheel.

The need for this addition to the tailstock is that with these smaller machines, the drilling forces at the handwheel feel like you're pushing a much bigger drill than you really are. This is due to both internal friction in the tail stock (Plain bearing made of steel) and the relatively small size of the handwheel. Having a larger and more importantly, heavier handwheel also helps release the tooling from the taper when changing tooling.

On all but the smallest lathes, ie under 9" the handwheel has enough mass so you can "Whip" the handwheel in reverse, and let the inertia of the heavy wheel knock the tool out of the taper. This also helps when retracting the drill from the hole as with a heavier wheel you get more turns when you whip it, again, due to the mass.



I looked at a lot of different offerings for cast iron handwheels and really didnt like many of them. Wrong number of spokes for the size I wanted, cheap looking castings, low quality finish....

Then I found this from a company called Fixtureworks.



And its perfect!



IMG_4698[1].JPG



Almost an inch bigger (.800 and change) but still at a size where it wont look like clown shoes on this size lathe, and it will add a nice "Big lathe" look to the machine.

Before I could begin on boring the bearing pocket for the radial bearing I needed a carriage stop. I threw together a basic carriage stop made from a block of aluminum and a 14-28 bolt. Nothing fancy, just something that will work.




IMG_4679.JPG

Next I found some appropriately sized bearings on A-zon and got to work.


IMG_4699[1].JPG

I set up the 4 jaw and indicated the part in and got out my best available (At home) boring tool. It has a nice sharp brazed carbide insert and as I found out, far too much stick out for the length and diameter of the shank.


IMG_4680.JPG



It just wanted to chatter and make god awful noises, so this had to go.

So I went with my 2nd choice, an Edelstaal 1/4" boring bar and insert. Up to this point I hadn't used this boring bar and didn't know what to expect with it only being 1/4" in diameter. I love the whole line of insert tooling, well, everything but the price, but I got this in another lathe package and hadnt tried it yet. I have good results with the other turning tools in the line, and with no other options I dressed down the insert to fit the into 10mm hole in the handwheel bearing block and got to work.

Oooh, tiny!


IMG_4677.JPG



Tiny, but I was better able to eliminate excess stick out with this one and it performed very well.


Using a snap gauge (Sue me) to sneak up on the correct hole diameter.


Almost there....


IMG_4674.JPG





And done. Got a really nice finish and a nice slip fit on the bearing.




IMG_4678.JPG


IMG_4673[1].jpg
 
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Congratulations on a nice score! I look forward to seeing the modifications.
 
Based on the prices the Emco Compact 5s sell for I think you did well at $1200, particularly in that condition.

It is a shame that there are so few lathes in the space of the Prazzi and Emco lathes. I have a Prazzi SD300 and even in its current "needs a lot of work" state it is clearly in a different class than most of the Chinese lathes in the 6-8" space, being more solid and built to a higher standard.
 
Based on the prices the Emco Compact 5s sell for I think you did well at $1200, particularly in that condition.

It is a shame that there are so few lathes in the space of the Prazzi and Emco lathes. I have a Prazzi SD300 and even in its current "needs a lot of work" state it is clearly in a different class than most of the Chinese lathes in the 6-8" space, being more solid and built to a higher standard.


First thing you should do after getting it functional is the tail stock mod. It makes a world of difference in the feel when drilling or doing any other operation with the tail stock.

Details here, post 3.






ETA: had trouble with the link and forgot about the EMCO comment.

Ther made some really good stuff back in the day and were affordable for the most part.

The problem was for a long time they lacked name recognition as people were still thinking Atlas/Craftsman/Rockwell for machines like this and in some areas you could go to sears and physically touch the machines.

I’m honestly not even sure how EMCO was distributed back then, but the first one I ever saw in person was a Compact5 mini CNC.


This was a teaching tool for CNC programming back in the early 90s built like a production machine. The tech school I went to during my apprenticeship had this and I was really interested but couldn’t take on the course work in order to learn to program it.

Cool as hell, but it just sat there and probably was sold at scrap price when the school closed.
 
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I had not taken a close look at this brand lathe before...

Looks very rigid for this small a machine. MUCH better than the other Asian lathe offers in this size.

NICE SCORE!

btw. YOU SUCK
 
First thing you should do after getting it functional is the tail stock mod. It makes a world of difference in the feel when drilling or doing any other operation with the tail stock.

Details here, post 3.






ETA: had trouble with the link and forgot about the EMCO comment.

Ther made some really good stuff back in the day and were affordable for the most part.

The problem was for a long time they lacked name recognition as people were still thinking Atlas/Craftsman/Rockwell for machines like this and in some areas you could go to sears and physically touch the machines.

I’m honestly not even sure how EMCO was distributed back then, but the first one I ever saw in person was a Compact5 mini CNC.


This was a teaching tool for CNC programming back in the early 90s built like a production machine. The tech school I went to during my apprenticeship had this and I was really interested but couldn’t take on the course work in order to learn to program it.

Cool as hell, but it just sat there and probably was sold at scrap price when the school closed.
Was the compact 5 this one?


There's a rather rusty Maximat Super 11 on eBay for £850 (same model as Stefan Gotteswinter had before he swapped to his Weiler), and if I hadn't stretched my finances to near breaking point with a holiday and too much recent workshop spending, I'd be tempted as it's only 90 mins away from me.
 
I’m honestly not even sure how EMCO was distributed back then, but the first one I ever saw in person was a Compact5 mini CNC.

Sears sold the Compact 5 and Compact 8 under the Craftsman name for a short period after they dropped the 6" Atlas. Beyond that I really don't know how they were distributed in the USA.
There was supposedly some falling out between Emco and the North American distributor of the Unimat around the time the Unimat 3 was released. Some on the Unimat forums have blamed for this dispute for the Unimat 3 being much less popular despite technically being a better machine. That may have crossed over to impact distribution of the larger Emco machines as well, explaining why they are so uncommon. Prazzi was East German until 1991 so it makes sense why they are fairly rare in the US.

Sears sold the Compact 8 for $1199 in 1981, the same year they were selling the Atlas made Craftsman 12" with QCGB and cabinet base for $2300. Emco were not inexpensive machines. $1199 in 1981 would be about $4100 adjusted for inflation.


Craftsman 8 inch lathe Emco Compact 8.jpg

The Compact 8 was clearly the inspiration for the 9x20 now sold by Grizzly, Jet and others.
 
2nd one for me.

I found this offered on FBMP for a rather high price and the seller claimed it was new. It certainly looked good in pics, but at 2K it was much too expensive even if it was new. I haggled with the seller over this for more than a month and had it in my head I was maxed out at $1100.

After 6 weeks the seller gradually dropped the price down to $1400, but told me in a PM he would take $1200. Being afraid to lose it as it was now in line with offerings from PM and LMS, I jumped on it. Knowing the quality, both in manufacturing and design I couldn't resist the opportunity to have a brand new lathe to build out into what I had planned on for the first SD400 I bought.

A clean slate so to speak.


And other than some shelf wear, this machine is indeed brand new. Never made one chip as hard as that is to believe.


Here it is next to its little brother the day I got it home. I initially thought the brown on the compound was rust, but it was only WD40 mixed with sawdust.



img_4512-jpeg.499761





Little staining from the WD40 is all there was after a wipe down.

Doesn't look as bad in person, the camera picks up every bit of color.


img_4520-jpeg.499768





There are no chips or signs of use anywhere. The brown spots are WD and sawdust.



img_4519-jpeg.499767


img_4516-jpeg.499765




The flaking on the ways is still pristine. This is before it was even wiped down, the entire bed is pristine.


img_4515-jpeg.499764





My plans so far are are for a Custom Crafter motor and controller upgrade, tailstock thrust bearing and upgraded handwheel and an electronic lead screw kit. Im not sure what ELS kit Im going to use as of yet. The one that Clough uses dosent inspire me, but this guys kit looks promising.





So, first things first. Im kinda back on a budget after putting out the money for this so I have to work at the lower cost upgrades first. No big deal as the first modification Ill be making is similar to one that made a huge improvement on my SD300, radial and thrust bearings in the tailstock. But with this lathe I decided to upgrade the tailstock handwheel to a larger, heavier (10-12 times the mass of factory handwheel) cast iron handwheel.

The need for this addition to the tailstock is that with these smaller machines, the drilling forces at the handwheel feel like you're pushing a much bigger drill than you really are. This is due to both internal friction in the tail stock (Plain bearing made of steel) and the relatively small size of the handwheel. Having a larger and more importantly, heavier handwheel also helps release the tooling from the taper when changing tooling.

On all but the smallest lathes, ie under 9" the handwheel has enough mass so you can "Whip" the handwheel in reverse, and let the inertia of the heavy wheel knock the tool out of the taper. This also helps when retracting the drill from the hole as with a heavier wheel you get more turns when you whip it, again, due to the mass.



I looked at a lot of different offerings for cast iron handwheels and really didnt like many of them. Wrong number of spokes for the size I wanted, cheap looking castings, low quality finish....

Then I found this from a company called Fixtureworks.



And its perfect!



View attachment 503971



Almost an inch bigger (.800 and change) but still at a size where it wont look like clown shoes on this size lathe, and it will add a nice "Big lathe" look to the machine.

Before I could begin on boring the bearing pocket for the radial bearing I needed a carriage stop. I threw together a basic carriage stop made from a block of aluminum and a 14-28 bolt. Nothing fancy, just something that will work.




View attachment 503893

Next I found some appropriately sized bearings on A-zon and got to work.


View attachment 503972

I set up the 4 jaw and indicated the part in and got out my best available (At home) boring tool. It has a nice sharp brazed carbide insert and as I found out, far too much stick out for the length and diameter of the shank.


View attachment 503894



It just wanted to chatter and make god awful noises, so this had to go.

So I went with my 2nd choice, an Edelstaal 1/4" boring bar and insert. Up to this point I hadn't used this boring bar and didn't know what to expect with it only being 1/4" in diameter. I love the whole line of insert tooling, well, everything but the price, but I got this in another lathe package and hadnt tried it yet. I have good results with the other turning tools in the line, and with no other options I dressed down the insert to fit the into 10mm hole in the handwheel bearing block and got to work.

Oooh, tiny!


View attachment 503895



Tiny, but I was better able to eliminate excess stick out with this one and it performed very well.


Using a snap gauge (Sue me) to sneak up on the correct hole diameter.


Almost there....


View attachment 503896





And done. Got a really nice finish and a nice slip fit on the bearing.




View attachment 503897


View attachment 503898
Looks good...
 
Looks good...


Thanks man, I'm having a blast.


I got so into adding the ball bearing and thrust bearing to the tail stock I forgot a step that got me here.

When I initially got the machine home the carriage would not move, like not at all. I was made aware of this by the seller and hoped this was the case, reinforcing the sellers claim of it being a new machine that had not been used. These Machines were shipped with a shim kit for the carriage "hold downs?", don't remember exactly what the addendum sheet called them, and stated these were shipped with the carriage locked via these two front hold downs and the shim kit should be used to adjust the proper clearance of these for proper operation.

My guess is this was to prevent the carriage from slamming around during shipping?

Of course the shims and flyer were missing when I got this machine, but I had the info from the documentation included with the other used lathe I purchased earlier.

No big deal, I took then down on the surface grinder and made them fit perfectly. .0007 off of one and .001 off of the other.

Here they are ready to go back in for the final time. Took a couple times to get them right, but there's no simple way to measure how much to take, so trial and error is the way to go.




IMG_4718.JPG




Getting back to where I left off, I wanted to open up the radial bearing pocket just a little (.0005) and add a relief cut to the bottom for clearance of the corner of the bearing. I'm trying to be as precise as possible because I only have .070 wiggle room at the back of this plate and I don't want to make it too thin there. The back surface is where the hand wheel rides and takes the force of nocking the tool out of the taper so I don't want to weaken the plate there.

I blued the bore as to be able to creep up on a light touch due to the very small amount of material I need to take. I brought the tool bit in with the spindle static in small increments until the toolbit just scraped the bluing. You can see the scrape on the right hand back portion of the hole. You have to make an adjustment, run the carriage in and rotate the chuck to look and see when you come to a touch, but this eliminates the problem of accidentally taking material out of the bore by accident if you were to do this with the chuck rotating.

Remember, I'm only looking to remove .0005 from the bore, that's only .00025 per side so I really need to sneak up on it..





IMG_4706.JPG




Then I took a trial pass to find I was just scraping the bluing, perfect! . The bluing is generally .0002ish thick depending on how light or heavy you apply it. I'm just scraping it clean from the surface here without removing material.


I took the required amount , made a clearance cut on the corner at the bottom of the bore, then cleaned up the bottom of the bore in the final pass.


IMG_4707.JPG





Then I cut the thrust bearing pocket. Boring out this second detail was quick and easy as I only had to be concerned with the depth and having enough side wall clearance for the thrust bearing to rotate freely.



Pic looks like hell, but if you look at the 2 o'clock position you can see the two steps for the different bearings and how badly everything needs to be deburred. The blue portion is the bottom of the radial bearing pocket, the brown is the bottom of the thrust bearing pocket, and the burr on the face is the burr on the face that needs removed.



IMG_4711[1].JPG




With that done I test fit everything and found it all to work well. I stacked up the bearings on the quill screw and assembled the whole works and function checked. It was at this point I realized I was not done, there is no provision from the factory to oil the quill screw bearing and no way to get oil to the bearings I just added.



IMG_4715.JPG




Taking inspiration from the SD300 lathe I decided to install a small set screw to provide an oiling port.


Looking at it from the inside.


IMG_4716.JPG





And when assembled.




IMG_4717.JPG




This works better in this arraignment than a ball oiler as #1, there's no room for a ball oiler and B, if I did want to install one I would need to make some complex oil gallery to get the oil where it is needed, between the radial and thrust bearings.

And having this step finished I'm happy to report the tailstock is smooth as butter and nearly friction free.

I cant wait to drill something, but I still have another tailstock from the other SD400 to do and I don't want to break down the 4 jaw for basically the same setup.

This mod combined with adding the larger cast hand wheel (Coming up next) will make drilling much more pleasurable.




.
 
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