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I would use a small grinder instead of a lathe tool. If you have a dremel like grinder you can clamp in a vise and use it to resurface you spindle nose. Just my 2 cents
Jeff E.
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I am asking this here because the question is regarding TTS preparation AND I have seen people mention this in this forum... so please forgive a lowly X3 owner who lays awake at night dreaming of dirty-ing my future 1100.
I did a bunch of testing for comparison between the SMITHY TTS Holders (yes, they actually do have "TTS" laser engraved on them with the exact font as the Tormach TTS, but more on that later) and the Tormach version.
My findings were a little shocking, but out of fairness I'm going to order a brand new Tormach holder for comparison and surface my spindle nose.
I have less than .0005" TIR inside my spindle on the taper, and on the vertical (this is on an X3). With a drill rod chucked in a collet I sill have slightly less than .0005" TIR at .1" from nose, and just over .0005" at 1". HOWEVER indicating the nose itself in the area where the TTS flat contacts I have .0007ish run outthis translated to .0015"+ on all SS holders I checked and significantly more on the ER20 holders as they are further from the nose. Honestly shocked since I can slot within .0005 using full width, then.0005" finish on each side. I've done this with .031-.375" with excellent accuracy.
Anyways, want to surface the nose. I have some new lathe bits for my flycutter but having no practical knowledge of lathes I'm a little scared. SS at 1.5" should be 300ipm(right ?) but I don't know how deep to cut or how fast.
My nose has two holes for a spanner just outside the TTS contact area. will interrupted cuts in SS chip the HHS cutter? Should I face the whole nose... seems silly to stop just inside the holes.
Should I surface the entire nose using the surface speed for the area of importance and leaving the surface speed for the outer area suffer as it is less important?
I'm thinking just chuck lathe tool in vise, align what would be slightly "below" center on a lathe, zero on spindle, write code to take .0005 at something slow like .5 ipm???. This may not even touch the surface given any error. repeat and indicate surface as necessary.
When it comes to damaging the spindle I would rather ask stupid planning questions than stupid repair questions.
I would use a small grinder instead of a lathe tool. If you have a dremel like grinder you can clamp in a vise and use it to resurface you spindle nose. Just my 2 cents
Jeff E.
Very interesting idea! I have a mount I made for my dremel wand, but the dremel just vibrated too much and was useless for engraving (picture below).
I can mount just the last block in the vise and skim the face easily. Any guess on a good starting point for feed, DOC and dremel speed to avoid wearing the bit mid surface?
(Thinking out loud... well, the keyboard clicks are audible) I'm thinking going to slow could heat/warp the spindle slightly and wear the abrasive so that the radial surface would be uneven (cone). Really I don't think it would mater since the tool will only contact the highest point within the contact area and I couldn't see the difference being detectable within a small area. Plus with the grinder I could grind in both directions.
spindle has 5600rpm available, dremel has 35K IIRC. I'm thinking max speeds on both and 15ipm taking multiple passes at .0007 DOC (from current low point) until the sparks stop flying. thoughts?
Looks good, but you should run the mill's spindle slower. In this operation, the dremel is the spindle, and the mill's spindle is the feedrate. I would run the mill's spindle at a minimum RPM. That will reduce stress on that cheap plastic spindle, especially when it gets to the interrupted cut.
Your depth of cut is OK, but you should do some finish passes at 0.0001" - 0.0002" DOC.
You will want to dress the Dremel's stone before you start. Mount a dressing tool in the mill's spindle, and very slowly feed it across the Dremel's stone.
Re-dress the stone before your finish passes.
Use coolant to avoid heat warping.
[URL="http://www.pure-geometry.com/"]Pure Geometry LLC[/URL]
Vertical Lathe tool holders and more.
Excellent points. I think that is exactly what I will do.Originally Posted by TXFred
The only dressing tools I have used are the wheeled and hand held. For this I'm thinking multi-point or integral. Not sure which. The integral from mcmaster is only a few bucks more so cost isn't an issue- which is better for this application on a small stone? Any thoughts on how large of a contact patch I should create?
I recently tried using a flex shaft tool on my lathe as a toolpost grinder. It was similar to what you're doing now.
I used a single point diamond dressing tool. Mine was on a .375" shaft, so I was able to mount it to a magnetic base and position it as needed. Take shallow cuts when dressing, half a thou at the most.
I recommend keeping the contact patch small. The 1/8" shaft and plastic spindle are going to introduce a lot of flex. By reducing the contact patch, you reduce machining forces.
I used the Dremel 85422 stone. It's got a small contact area and gives great results, so long as you're patient.
I'm curious, do you have a bench grinder? If it's got an accurate enough spindle, you could remove the rubber feet, remove the guards, clamp it to the table, and use it in place of the Dremel.
Frederic
[URL="http://www.pure-geometry.com/"]Pure Geometry LLC[/URL]
Vertical Lathe tool holders and more.
LOL... first thing that came to my mind was just throwing one of these little guys in my vise
my bench grinder has too much run out unfortunately.
I think I'll pick up a dressing tool and give the dremel a go this weekend.
I have a vague recollection of Tormach giving some recommendations regarding truing the spindle face. You might want to do a search on their web site.
Start with the TTS white paper and the bulletins.
Phil
PS: I think a carbide lathe tool wouldn't have to much trouble.
See page 5 of the Tormach Tooling System Manual here:
Product Documents | Tormach LLC | We provide personal small CNC machines, CNC tooling, and many more CNC items
Phil
duplicate post
The manual for the TTS says 0.025mm run-out. The test certificate for the PCNC 1100 says 0.02mm. I might be wrong but both these values seem a bit excessive. I would expect a light skim with a lathe tool will do a lot better.
I would be interested to see what you achieve. I think it will be important to ensure you have a decent preload on your spindle bearings when you do the facing.
Phil
very odd to me that .001" on the nose is acceptable. That means I have roughly half of the allowed error.
This inspired an additional test that I overlooked which is to try 3/4" drill rod in the TTS collet as the collet itself may be causing the error.
I already smacked my forehead, so tonight I'll chuck a 3/4 em and check the collet, then give a go with a lathe bit since its free and see where I am. If I'm not happy I'll buy a diamond dresser
Still would like any input on speed and feed for the lathe tool.
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