Working on a new-to-me Deckel KF-12

And have some questions for folks with experience with the internals:

Q1 - Variable-speed belt drive:
The floating steel double-taper sheave (is there an official name for that?) in the center of the Reeves-style drive seems to ride on a bronze bushing. Problem is, the sheave slides freely on the bushing (first picture).
My thinking is this shouldn't happen, as it could mean that the sheave wobbles as it slips partly off the bushing (hypothesis potentially corroborated by the 36" of belt reinforcement I unwound from the central hub).
So, I got some Loctite 680 retaining compound (second picture) which should hold it nicely once cleaned and fixtured.
I just wanted to check that I was doing the right thing, as this is one of the assemblies that Deckel apparently felt shouldn't be user-serviceable and so the operator's manual skips right over it. Also, any clever tips on centering and squaring the bushing before gluing it in place would be appreciated - I was just going to nestle the cone into a big bearing race, space up to center, and run a DTI around the edge to check wobble.



Q2 - Drag table bellows:
Got lost somewhere along the way. Does anyone know if it's worth pinging Germany (Singer, etc...) for replacements, or have ideas for jury-rigging substitutes? I'd rather not get the little bearings in there all full of chips.

Q3 - Spindle removal:
Spindle is - I think - in good shape, but appears to be seized into the casting. A) is it worth removing, or should I just resign myself to servicing it in place when necessary? (I don't currently have other spindles to swap in, so that bit is a moot point). B) if worth removing, any bright ideas for getting it out? Force and heat are both contraindicated, and there's precious little to grab onto...

Q4 - Belt choice:
The variable drive came set up with some pretty worn but standard stock v-belts, and I picked up replacements accordingly - any known issues with using plain old 4L belts instead of ze spezial-vari-expensive belts I'm sure were initially specified? (Also the same question for the final spindle drive belt except it's a 3L). See pic - old on bottom, new on top.


Q5 - Stylus collets:
Are these just GK-21 (et. al.) Deckel collets? Anyone know where some might be found for less than $80/ea and shipping from Germany?

Last question: know it's a long shot, but if anyone has KF accessories they're interested in selling or trading, PM me or drop a note here.

I'll try and keep machine repair all in this thread, unless it gets too unwieldy, but will start another for projects as soon as the drive is fixed & everything's reassembled!








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Opinion #1:
Forget the sleeve retainer...I.fight this all the timer here at work....Mechanics encounter a part that is worn and has a loose fit...they always want to glue it up ...quick, cheap and easy.....
Almost always at a later date when that same part is re-visited the loose part is loose again.
Loctite makes some great products....in my opinion sleeve retainer is not one of them...its just not reliable at repairing "WORN" fits!

Make a new bushing from fresh material...perhaps go for something a bit tougher such as 954 for the bushing...Press it in or better shrink fit it in place....
Finish the running surface to size and true once installed by indicating the pulley to run round and flat...If the seating area where the bushing fits is worn, true that up before making the bushing to suit...

Worn Reeves drives are very annoying , noisy and all...Fix it properly and it will be good for quite some time...
Cheers Ross

Thanks, Ross!

Advance notice: just 'cause I may ignore your opinion doesn't mean I don't appreciate it :-)

Point taken about fixing it right. That said, this is about the smallest Reeves-style drive I've ever seen, with all the clamping forces taken by three 3.5mm flatheads and some cute li'l lockwashers (see pic). And there's about 3 square inches of surface area for the retainer, with <.009" radial gap.

Right now it's the only thing stopping the machine from running, and by the time I make a shrink-fit bushing and fix it right it'll be summertime...

If and when it comes loose again, I'll let you know, you can say "I told you so" and I'll owe you the cold beverage of your choice.

Now back to degreasing...

-Zac




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The original center disc on a Deckel variable drive was Bakelite and it floats up and down as you change speed. It wears out and flops while turning and makes for vibrations while running. It also causes the variable unit as a whole, to twist when you turn on the spindle. I have replacement units that I got years ago which have an iron center disc with a brass bushing lightly pressed in. If your bushing is not pressed, maybe your center disc is supposed to ride up and down on the brass. Is your brass bushing as long as the center steel or is it only as wide as the center pulley?
I've seen bellows for the drag table joint but most people replaced them with a simple cover that folded over a 3/8" rod at each end. This was available from Deckel.You could try and make your own maybe out of thin leather. Vinyl won't work
because hot chips will melt and stick to the vinyl.
But getting anything from Germany, if available will be very expensive. I bought bellows for my GK21 years ago and paid $700.
The spindle should move up and out freely once the two cap screws are loosened. If it is stuck, it might be rusted from cleaner or moisture getting in the slots near the cap screws. You could try using some penetrating oil such as liquid wrench or PJ Blaster and let it soak. You could try blocking up the spindle on the work table with some hardwood and then tap down on the parallelogram (the big part that says Deckel) to break the spindle loose.
I have original spare belts for my machines but I did try and match up with regular "L" belts but I'll have to check and see if I was able to find a suitable replacement.
The final belt should be a round rope belt. A V belt in that section would only be used if you have the roughing spindle which had gear reduction in the head. If your spindle turns the same revolutions on top as bottom, you need a round rope belt for the final belt. If you use a v belt, it will come off the pulley as you move the whole duplicating mechanism up and down. I have extra round belts.
The stylus collects are larger than GK21 collets. Early KFs had small finish spindles which used the same collets as the stylus side. Then a larger finish spindle came out and it has larger collets. If you have no stylus collets, I have some extras.
I have angle spindles, the symmetrical attachment I might want to sell.
I have the enlarging reducing attachment but I'm working on selling one of my machines with that attachment now.
I would like to get the immobilizing bracket which is often used to secure the duplicating mechanism and photograph during shipping.
It seems these Deckels are going to hobbyist users now, as such, the accessories don't seem to sell for much. I find stuff at Ebay occasionally and I emailed one guy who got $1250 for his enlarging reducing attachment.
Maybe you could message me with what you might be willing to spend on some needed items and your location because shipping could be very expensive. I'm in northern Illinois BTW.

It's the light press fit that's an issue here - the bushing is about 60 thou longer than the center disk is wide (see first pic) and clearly has loosened and wobbled.

Thanks for the hint on bellows! If you happen to have any pictures of the shop-made versions, let me know - am having trouble visualizing it at the moment. Seems like bellows are probably one of those things that seem like black magic but only until you know how they're made, but that'd be a project for quieter times.

Spindle is indeed stuck & currently soaking - good thought about blocking it up and tapping the parallelogram (also good to know what that's called) - though I can't figure out how to block it so that the load wouldn't come through the spindle bearings... will take another look next week.

I picked up a 4L235 and a 4L250 belt - length and width seem right, just wanted to check that they wouldn't cause excess wear or anything.

I have the semi-finishing spindle (up to 10k rpm) with what looks like a round belt groove on top and a v-belt groove on the bottom - does the bottom groove take a huge round belt? It'd have to be something like 8mm, but I can see how the v-belt would slip off at high angles... interesting. I'll PM you. Any experience with solid urethane belts like Singer offers on eBay?

Good to know about the stylus collets! I have one 1/2", which should work fine for most things, but will PM you about extras (and the symmetrical attachment - angle spindles I don't think I'd be likely to use).

The enlarging attachment is probably worth more than I can justify paying (I'm definitely in the hobbyist category).

Can't help you on the immobilizing bracket, my machine came only with straight-line attachment (minus follower roller and clamp screw), drag table, and one collet per spindle. Probably should have asked you about machines first :-) but got a really good deal on mine and it seems in nice shape so far (except for the drive, which may have helped keep the rest unused!).

Thankfully less a case of needed items and more wondering about any accessories that could be had without having to buy a second machine :-). PM coming shortly!

(Edited for spelling)