SK40 collet holder does not interface with drive ring dogs

So I have one of these SK40 collet holders:

A couple of questions:

1) There are no notches for the drive dogs on the drive ring. This seems wrong to me. There is nothing to prevent it slipping inside the spindle, resulting in galling. What am I missing?

2) Is the sole purpose of the threaded ring (shown threaded on in photo) to eject the holder should it become stuck? Using this in operation seems as if it would only serve to pull the tooling out.

Thanks for your help. I just want to make sure I'm using this thing properly.

crpearson said:

1) There are no notches for the drive dogs on the drive ring. This seems wrong to me. There is nothing to prevent it slipping inside the spindle, resulting in galling. What am I missing?

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In principle you are right, this is not protected against slippage. This adaptor is for use with collets that have a range from 0.5 to 16mm (or inch equivalents). I typically do not use this for any heavy milling, and expect that if anything slips, it will slip inside the collet, rather than having the SK40 adaptor slipping inside the milling spindle. But you are right to be cautious: don't use this for heavy loads.

2) Is the sole purpose of the threaded ring (shown threaded on in photo) to eject the holder should it become stuck? Using this in operation seems as if it would only serve to pull the tooling out.

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That's correct. Deckel made three different forms of this adaptor. One of them has NO extraction features, and can get impressively stuck. The second has a pair of flats for "turning" with a wrench, and can also get very stuck. The one you have is the best variant. I use it often if (for example) I want to clamp a drill bit with the best possible concentricity.

Thank you very much for helping me understand this, Ballen. I really appreciate it! I'll use it cautiously and not under heavy loads.

crpearson said:

Thank you very much for helping me understand this, Ballen. I really appreciate it! I'll use it cautiously and not under heavy loads.

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Glad to help, and welcome to this forum. I saw your beautiful FP1 in the "Registry" thread. FYI the other two types of these collet holders are shown in post 3 of this thread.

ballen said:

Glad to help, and welcome to this forum. I saw your beautiful FP1 in the "Registry" thread. FYI the other two types of these collet holders are shown in post 3 of this thread.

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Thanks for the welcome and kind words about my new machine. I'm extremely excited about it! I had actually been saving my pennies for another machine (FP-1 copy) when my local dealer (and friend) called me up and told me he had a line on a "really well equipped and clean two-dial FP-1". I almost could not believe how much tooling and accessories it came with! Also, it was only about three miles from my house. A bit more than I wanted to spend, but with all the extra equipment it was a good deal.

Thank you for the link on the collet holders. It actually has the second generation one you mentioned as well -- the one with the flats for turning with a wrench. I took one look at that thing and though it seemed like it was just asking for trouble. I guess turning it with a wrench would get it unstuck, but that doesn't seem like it would be good for the spindle. Maybe I've just read too many articles about the nightmares of getting tooling unstuck from Deckels. This is the nicest machine I've ever used and I really want to take good care of it.

Thanks again for all your help! I'm sure I'll have some more questions along the way.

Cliff

Hi Cliff,

Your machine looks well-tooled and pristine. If it only cost "a bit more" than you wanted to spend, then you got a very good deal.

FYI here is a puller that I made for removing stuck collet holders, which I will send around the world on request (with the caveat that it must be returned to me after use). At least once a year someone turns up here on the forums who has a badly stuck collet holder in their machine. In one case it was a morse taper holder which was so locked in place that it needed to be machined out.

I own all three types of these original Deckel SK40 collet holders but only use the one with the extraction nut.

Something that I suggest you check on your machine is the shear pin that provides overload (crash) protection for the feeds. This should be made from free-cutting steel so that it shears at reasonable loads. In some cases the previous owners replaced this with (for example) a hardened nail, because after shearing the original pin in a crash, they did not have a correct replacement shear pin on hand. So if this shear pin is not correct, then you should replace it asap.

The other thing to be careful about is lubrication. In some cases people have pumped grease into the "grease nipples". But these are NOT grease nipples, they are meant for oil, and if they are greased, this clogs up the lubrication system. So read the lubrication instructions carefully and purchase the correct types of oil before doing anything else. As a general practice it's a good idea to drain and change the oil in the machine, since it may have been there for decades, and you can not trust that the PO put in the correct types.

Cheers,
Bruce

Hi Bruce,

That puller is elegantly simple and I would imagine it's bailed quite a few unhappy new Deckel owners out of a real predicament. I can't even imagine having to machine a holder out of a spindle. Even assuming the taper would be reground, that has to be a scary operation on a spindle that's no longer made. This machine came with a number of taper adaptors, but most of them include no strategy for extraction. One looks like it was heated quite a lot at some point. Luckily the Morse #4 + tang adapter uses the normal draw stud, so it is something I feel like I could safely use.

Ordering oil was actually the very first thing I did. The machine came with meticulous notes on when the oil was last changed and with what. It was changed just under a year ago with Mobil DTE ISO 68. There were some correspondence regarding oil printed out from discussions on this forum which indicated this was the right oil. Anyhow, I took photos of what I bought. Hopefully it's right.

I have not changed the oil since I was trusting his logs. Since you mention it though, I'm starting to think I will. It's cheap and easy insurance.

I did as you suggested and checked the shear pin. The machine actually came with a Deckel branded bag of spare pins, so I compared the one that was in there against those. it appears to be genuine. I forgot to snap a photo when I had it out. Thanks for mentioning that. It would be a horrible thing to tear up the power feed gears due to a nail.

I've read the lubrication instructions and followed them as best I can. They are not heavy on the details. Oil seems to flow into the nipples easily enough, but that's not necessarily saying someone didn't shove grease in there. Again I was trusting the previous owner on this, but that's probably not smart. I suppose the only way to be sure is to dig into it. Good thing I have a free weekend. I'll report back on what I find.

Thanks again. You're really helping me think through all the nightmare scenarios and I very much appreciate it!

Cliff

Your machine has an SK40 spindle taper, and those have far less tendency to lock up than earlier FP1 machines which have a native MT4 spindle taper. So you should be fine.

The Vactra #4 (ISO 220 way and lubricating oil) is the right choice for the Z/X ways and support/saddle. The original manufacturers recommendation in the 1960s for my own machine was more equivalent to Vactra #2 (ISO 68 way and lubricating oil) but eventually shifted to the heavier weight 220 version.

For the gearbox/feeds/Y I have been using ISO46 rather than ISO68. Again this is based on 1960s recommendations and this may have shifted to a heavier oil later. I know many people are using ISO68 here, so I think that is also a good choice.

The shear pins are original, all good there.

Based on the condition and the fact that the PO had lubrication notes and a schedule, it's unlikely that the machine was pumped with grease in the wrong places. But the instruction manual should include a full lubrication schedule and diagrams. If you don't have that or don't understand it, ask here. I don't have your exact machine but there are many others here who do. The people who frequent these forums are a treasure trove of knowledge and information and will get you up the learning curve very fast if you just ask.

By and large, the maintenance schedule is clear enough. I do have a few areas where things are not particularly clear:

1) #7 in the schedule below: While there are detail pages for many of the items in the schedule, there is none for this. The only logical place I can see to lubricate the hand wheels is between graduated dials. Is this correct?

2) #11 in the schedule below: This table indicates that the only lubrication here is to disassemble and lubricate the spindle bearings with Isoflex grease every one year, or 8000 hours. Another schedule (also pictured below) suggests this, in addition to oiling it in the ground keyway monthly. I'm not sure if this is an updated set of directions or if it applies to a different model of spindle. I'd hate to wash out the Isoflex grease with oil.

Unfortunately, there is absolutely no doubt that someone, at some point, pumped the saddle full of grease (photo below). I will start looking into just how major a surgery this will be.

Thank you very much for your help and advice, Bruce. I hope I'm not wearing out my welcome and making you sorry you offered your assistance.

Cliff

Hi Cliff,

Sorry for the slow reply.

crpearson said:

#7 in the schedule below: While there are detail pages for many of the items in the schedule, there is none for this. The only logical place I can see to lubricate the hand wheels is between graduated dials. Is this correct?

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These are "safety wheels" which can spin freely. They may have an oil nipple on the side or center which puts oil into the spinning bearing in the center of the hub.

2) #11 in the schedule below: This table indicates that the only lubrication here is to disassemble and lubricate the spindle bearings with Isoflex grease every one year, or 8000 hours. Another schedule (also pictured below) suggests this, in addition to oiling it in the ground keyway monthly. I'm not sure if this is an updated set of directions or if it applies to a different model of spindle. I'd hate to wash out the Isoflex grease with oil.

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In the first case #11 is the horizontal spindle. Should have the grease replaced from time to time. Ross (AlfaGTA) has posted very clear step-by-step instructions for this. Was also recently done by Thanos here, again with pictures and a description.

In the second case (vertical head) the vertical spindle is "sealed" and as for the horizontal spindle, should have grease replaced from time to time. But the oil you feed in at the top goes over the bevel gears and bearings external to the spindle. So just follow the instructions.

Unfortunately, there is absolutely no doubt that someone, at some point, pumped the saddle full of grease (photo below). I will start looking into just how major a surgery this will be.

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Sigh. You need to remove the horizontal table and support, and clean them out.

The good news is that there are detailed step-by-step instructions on this. Given that your machine is in good shape, it will probably take you some tens of hours to do this. Depending upon where you are in California, there may be someone local who has already gone through this.

Thank you very much for your help and advice, Bruce. I hope I'm not wearing out my welcome and making you sorry you offered your assistance.

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Not at all. I have a large debt to others on the board here (Ross, TNB, Peter,...) who helped me to get my machine sorted. So I'm paying that back. Here are links to two threads that you should read through:

Getting the grease out of my FP2

Bill's FP1 grease removal thread

You have some work ahead of you, but the good news is that there are people here who have gone through every step. So you are not "flying blind".

Cheers,
Bruce

Thanks for the links, Bruce! Man, this is looking to be a fairly major surgery. That's alright though... It'll give me a chance to really get to know the old girl. I guess the part I'm least comfortable with is drilling out the gallery plugs. I saw you were hesitant to remove these as well. I guess I'm just going to have to get in there and see how much grease got pumped in.

I'll take good photos and start a new thread to document the process. This seems like a common enough problem that it might help others. I live in Santa Cruz, CA which is on the central coast. I don't want to take advantage of anyone's kindness, but if someone knowledgable in these things lives nearby, I would be willing to pay for a lesson or two. Particularly with the disassembly.

crpearson said:

I guess the part I'm least comfortable with is drilling out the gallery plugs.

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This is easy, but you first have to build or buy a slide hammer. It's necessary for many other steps of the disassembly as well.

Once you have that, drill and tap the plugs for M4 or M5 or similar inch threads. Then it's trivial to remove the plugs with the slide hammer. When you are ready to reassemble, you can re-use the plugs. First fill the threaded holes with a grub screw + teflon tape or with a grub screw + removable loctite.

There is one aspect that may require some care. After you remove the end plugs from a long cross gallery, as described above, you may also need to push out little plugs (~6mm = 1/4" diameter) that block the passages that come off that long cross gallery. On my FP2, I was able to drive these little plugs INTO the long cross gallery, and then just fish them out from there. But on the FP1 I am not sure if that's possible. You may have to drive them outwards.

In these three posts you'll find photos of that process for the FP2:

https://www.practicalmachinist.com/...own-reassembly-277534/index2.html#post2201244

https://www.practicalmachinist.com/...own-reassembly-277534/index2.html#post2201263

https://www.practicalmachinist.com/...own-reassembly-277534/index2.html#post2201722

I think that the FP1 thread which I link to above (post #10 in this thread) shows the removal of the little plugs, and it might be that they had to be driven outwards not inwards, I don't recall.

FYI I never use those drive dogs
But I never really do any hogging
Deckel FP3 - YouTube
As long as you do not use really big tools like 15cm diam you are good IMHO
And tighten the drawbar
Never tried it but with the drawbar tightened properly I do not think the machine even in low gear is capable of making the tool slip

Did anybody had a slipping tool once ???

Peter

Agree with Peter here if we are talking about a 40 taper machine....
The Morse spindle machines present more issues as operators are reluctant (with good reason) to fully tighten the draw bars for fear of sticking the holder in the spindle....
This can become a real issue if running for long periods of time at elevated RPM's where the spindle gets hot...then you need to change to a different holder and a cool room temp one is fitted....Can make for an instant shrink fit....

Its a sort of balancing act....the Morse holders have better grip in the spindles, but often see less tension on the draw bars in order to make removal easier....

Have little "seat time" with the Morse spindle machines (had an early FP1 for awhile) but i would say that no matter which spindle the drive ring would be a good idea when running a horizontal arbor with any sizeable cutter, or
large face mill...



Cheers Ross

A customer had a SIP co-boring machine with a morsetaper
After doing a big drilling job they left the drill in overnight
The drill was so stuck they ended up cutting it off with a angle grinder and drilling out the morse taper
So with a morsetaper machine when the head has gone warm/hot somewhat always remove the tool inmediatly when done

Peter

Peter and Ross,

Thanks for your thoughts on this. I spent a long time researching these mills before buying one and stories like that stuck drill is the reason I decided to hold out for a 40 taper machine.

Bruce,

Thanks so much for all those links. It has been a real education reading through them. I feel like I have a pretty good lock on what I need to do at this point. Now it's just about digging in I suppose. I'll start work on this in earnest this coming weekend.

One thing that makes me feel like it might not be all that bad is that I was able to pump quite a lot of oil into that system yesterday and it eventually came out the sight glass hole with no grease preceding it. If I'm reading the drawings correctly, the oil needs to traverse the majority of the galleries before I gets to the sight glass hole, so I'm hopeful that things are not going to be all that clogged up. I'll need to check before I can sleep well though.

Cliff

This work will go better with some planning.....
Organize the work area. You will need space to work and space for the parts to be set out.
A clean and well lighted space is essential to doing quality work.
Best if you have a table of workbench to set the vertical table (X) and slide on after their removal....
A nice accessory would be one of those hydraulic lift tables...nice because they allow positioning the work at convenient height for standing or working off a stool....

You will need some form of lifting device....Can use a chain fall or come along from above , but you will then need to be able to move the machine (rollers or skates) to get out from below the
parts once lifted off....
A shop crane is likely the best for ease of lifting and moving the parts...
An FP1 has relatively light and small parts, but not really within the working range of a single person...

Take lots of photos and refer to the parts manual for the position of internal parts...
I use notes, with sketches of the parts and any details of same...indicating thickness and position or shims washers etc,,,,i use an electric engraver to mark parts like gears to indicate the direction of assembly...
(right ,left front, rear etc)
I rely more on notes than photos...in my experience the act of noting the details and making sketches forces you to examine and remember the part and how it fits in the big picture....

Your machine is not complex, but there are some things to know when disassembling and refitting....

If you encounter an issue, stop and examine the parts and your procedure..if in doubt take some photos and post a question here...generally you will get a response in short order.
A word of caution...the setup of the FP1 is not the same as the FP2 (Bruce's syllabus on removing the grease from the slides)...They have similarities, but they are not exactly the same, and
the details are also a function of the build date...The Deckel design was carried for some time , and the factory made many changes along the way to improve the design.

Cheers Ross