Tips and tricks specific to the Prazi/Hobbymat machines.

RaisedByWolves

Mangler of grammar, off my meds.
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Our machines are some of the finest machines ever made in this size or class of machine.

In the past there were many competitors, but not all had the rigidity or power of the Prazi/H-Mat, so some specific tooling was created to help beginners deal with these other machines limitations. Im talking primarily the Sherline and Unimat machines, but there were others also.


Edelstaal, the parent company of Unimat, marketed some rather unique tooling, or should I say a tooling system designed around the limited power and rigidity of the two rail bed and sewing machine motor of the Unimat.

This was an excellent system both in the way it helped new machinists deal with the learning curve of grinding a suitable cutting tool, but also in the way these tools help make good use of the limited power of these machines.

How does this help us? Well, with more rigidity and higher power of the PRAZI machines, this line of tooling really begins to shine.

I work as a Toolmaker and once I found these little tools and tool bits, I was hooked. They are pricy, don't get me wrong, but they are also so good I've been keeping them a secret for a while as I build up my supply.1707867373414.png1707867428299.png1707867377554.png The profile of the tool bits gives you 90% of what you need to make a good cutting tool bit with only the slightest touchup on a belt sander (My preference) or bench grinder.


Literature from the 70s when these first became popular.



878a13e5966f354e568d7ddab0434f54.jpg
cts003 (1).jpg

cts004.jpg

cts002.jpg


Now if the literature doesn't get your attention, how about a demonstration.

Heres my machine with the Custom Crafter drive system taking a .060 deep cut (.120 on diameter) with the T-15 (Red/cobalt) insert on 3/8" O-1 tool steel. RPMs vary from 36-800ish on this cut.


 
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The factory tool post is somewhat problematic and should be changed out IMO, as improper use can lead to the top slide threads pulling out and ruining the slide. This is due to there being only two rather shallowly threaded "Fixing" bolts and compounded by the ability to clamp down onto 4 individual tool bits simultaneously. That is the total force of 8 bolts unevenly applied (Side load and uneven torque values) to just two bolts. This can inadvertently cause enough force to be exerted on the fixing screws to cause the top slide to fail.


1708106591000.png





In light of that, in conjunction with the tooling I'm using I've also added a quick change tool post from Banggood. Prices on these fluctuate, but their usually around $120 or so ($109 currently) and the brand I'm using is called Machifit.

These are OXA size and fit perfectly with little modification needed. Be careful and study the ad your buying from. Some of these are worded so poorly and can be confusing enough to lead you to order something that you do not want or at least less than you thought you were buying.


The above link is directly from my order page in my BG account, so its basically the one you want. However, the cutoff tool holder and knurl holder will not drop down far enough to work on the SD300 without making a custom plinth to replace the compound slide assembly. Their really not the best cutoff tool or knurl size for this machine anyway.


I initially made a plinth in order to be able to use the knurl and cutoff blade, but this seemed suboptimal in use so I shelved it and went back to using the top slide and I'm happier with it set up this way.


Plinth.

You can see I was just about out of vertical adjustment and needing a 3/16" tool bit under the Edelstaal tooling to get the height right.


1708107089003.png



IIRC I did have to turn down the tool post clamping bolt from 10mm to 8mm to fit the top slide, but other than that its a direct fit with the top slide in place.


1708107472925.png





If you poke around BG for this brand you can also buy separates to avoid winding up with the two undesirable pieces I mentioned above and possibly save some $$$ or spend it on extra tool holders that suit your needs.

I just now bought 3 of the 250-001 standard tool holders @ $7.99 each.

1707955948967.png
 
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Hello guys, hope all is well. Got a quick question. What would be the best quick change tool post for my Prazi lathe. Talking type and brands. Would love to know what you guys are using. Thanks in advance
 

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Hello guys, hope all is well. Got a quick question. What would be the best quick change tool post for my Prazi lathe. Talking type and brands. Would love to know what you guys are using. Thanks in advance
Sorry, just realized my question has already been answered above, however I would still like to hear what you guys currently use and any modifications that need to be made to improve or mount the tool oxa toolpost
 
The factory tool post is somewhat problematic and should be changed out IMO, as improper use can lead to the top slide threads pulling out and ruining the slide. This is due to there being only two rather shallowly threaded "Fixing" bolts and compounded by the ability to clamp down onto 4 individual tool bits simultaneously. That is the total force of 8 bolts unevenly applied (Side load and uneven torque values) to just two bolts. This can inadvertently cause enough force to be exerted on the fixing screws to cause the top slide to fail.


View attachment 478586





In light of that, in conjunction with the tooling I'm using I've also added a quick change tool post from Banggood. Prices on these fluctuate, but their usually around $120 or so ($109 currently) and the brand I'm using is called Machifit.

These are OXA size and fit perfectly with little modification needed. Be careful and study the ad your buying from. Some of these are worded so poorly and can be confusing enough to lead you to order something that you do not want or at least less than you thought you were buying.


The above link is directly from my order page in my BG account, so its basically the one you want. However, the cutoff tool holder and knurl holder will not drop down far enough to work on the SD300 without making a custom plinth to replace the compound slide assembly. Their really not the best cutoff tool or knurl size for this machine anyway.


I initially made a plinth tin order to be able to use the knurl and cutoff blade, but this seemed suboptimal in use so I shelved it and went back to using the top slide and Im happier with it set up this way.


Plinth.

You can see I was just about out of vertical adjustment and needing a 3/16" tool bit under the Edelstaal tooling to get the height right.


View attachment 478587



IIRC I did have to turn down the tool post clamping bolt from 10mm to 8mm to fit the top slide, but other than that its a direct fit with the top slide in place.


View attachment 478588





If you poke around BG for this brand you can also buy separates to avoid winding up with the two undesirable pieces I mentioned above and possibly save some $$$ or spend it on extra tool holders that suit your needs.

I just now bought 3 of the 250-001 standard tool holders @ $7.99 each.

View attachment 478360
Hi, on a little bit different topic, I noticed you have a tachometer set up on your lathe. What brand and how and where did you mount the pick up for it? Thanks
 
Hi, on a little bit different topic, I noticed you have a tachometer set up on your lathe. What brand and how and where did you mount the pick up for it? Thanks
The tach I have is integral to the Custom Crafter drive and is only indicative of motor speed, not spindle speed.

T-DRO has a tach function, and I plan on using that in the future as Im already set up for it, but there are several stand alone tachs that can be found on e bay and other sites that are good.
 
Hello guys, hope all is well. Got a quick question. What would be the best quick change tool post for my Prazi lathe. Talking type and brands. Would love to know what you guys are using. Thanks in advance
I have both this:



And this:




On two separate machines. I really like the multifix style tool post as it has some definite advantages, but the one from Ali just isnt up to par. Its not that it doesn't work, it just seems more fiddley than it needs to be and its just not as well made as the wedge style I got from BG.


PEWE Tools has a nice looking Multifix style tool post. Its 3X the price as the one I bought and individual holders are twice the price, so I would hope quality follows suit, but they do get good reviews.
 
I have both this:



And this:




On two separate machines. I really like the multifix style tool post as it has some definite advantages, but the one from Ali just isnt up to par. Its not that it doesn't work, it just seems more fiddley than it needs to be and its just not as well made as the wedge style I got from BG.


PEWE Tools has a nice looking Multifix style tool post. It’s 3X the price as the one I bought and individual holders are twice the price, so I would hope quality follows suit, but they do get good reviews.
Yes sir, the multifix looks like it would be the ticket. I’m probably gonna go with the wedge, at least until I get more familiar with the machine. I appreciate you pointing me in the right direction
 
I have both this:



And this:




On two separate machines. I really like the multifix style tool post as it has some definite advantages, but the one from Ali just isnt up to par. Its not that it doesn't work, it just seems more fiddley than it needs to be and its just not as well made as the wedge style I got from BG.


PEWE Tools has a nice looking Multifix style tool post. Its 3X the price as the one I bought and individual holders are twice the price, so I would hope quality follows suit, but they do get good reviews.
I do have one other question about the Prazi mill. I have a set of metric collets that came with the machine and I believe they are the original Prazi collet set that was available to purchase as an accessory. They look like a miniature R8 collet. Do you happen to know what they are called? Like are they a ER collett or something different
 
I do have one other question about the Prazi mill. I have a set of metric collets that came with the machine and I believe they are the original Prazi collet set that was available to purchase as an accessory. They look like a miniature R8 collet. Do you happen to know what they are called? Like are they a ER collett or something different

No idea.

I’ve read that they are proprietary, but I’ve also seen the same style collet nose for sherline or unimat and possibly ENCO.


Doesn’t mean the collets are different or the same, but the closer body looks similar.
 
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