Project Schaublin 135

[marcsO]

BRAKE #1

Decided to strip the brake as the motor is on the bench, the parts came off easily which is always nice, looking at the pressure plate all seems fine, might if the census agrees give the surface a quick skim and hatch it to give a nice surface for grip.



The electromagnet and brake pad part looks worn, the brake pad medium is only just proud of the metal edges, possibly less than 0.5mm so I am assuming this is well worn - can someone let me know what sort of material thickness should be proud of the metal surfaces and what a new unit would look like?

I'm guessing this part is the part needing replacing, any indicators of what this might cost?



The plastic bushes and pins with the spring assembles are out and yes the bushes are worn, as someone suggested this is a poor design but not sure there is an alternative solution to re-maching new ones from delrin or similar... could you use oilite brass bushings?



The spring set up on the three pins seems strange, one the inside there is a spring and a cup washer that has a ring under which slides up and down the shaft of the pin, there seems no real reason for this as it wont slide unless you manually move it, is this the correct working method and how should the pins/springs be set up?

Tidied up some of the wiring in the motor connection box and will wait to find out what is what with replacement parts for the brake....

Before

After

 

[marcsO]

BRAKE #2

So after a quick check in with Schaublin an indicative quote for 4K to replace the brake assembly as a whole was provided - they don't do the individual parts I contacted Warner in the UK as that price would be madness to part with.

Interesting feedback, there was me thinking the brake worked similar to the brake in a car where the friction material or 'pad' was the contact point and this created the resistance to rotation when forced against the metal 'disk' or armature in the case of this system. Well thats not the way this works, the metal surfaces either side of the friction type material are actually the contact surfaces, so its a metal on metal contact, the medium between the metal rims should be just below them.

I will look to re-machine this on my brake as it looks like they are just below the friction material and then see how we go. Either way it is good news in that my brake does not appear to need replacing, well the electromagnetic side anyway, and for those interested I was sent a useful document which helps explain the brake system, how to test it and what to do to get it working as designed. Hope it helps and will add this to the growing parts which need some machining etc.....

 

[marcsO]

First items have arrived for the planned oil line upgrade, these are two diameters of hard wall nylon tubing which I am hoping will replace the copper/brass tubing fitted to the banjo's.

I noticed the feed lines were 10mm OD whilst the returns were 12mm OD on the original copper/brass tubes so have done the same with the nylon pipe and will be using 10mm OD feed up to gearbox etc and 12mm OD tube for the return to oil tank reservoir.

The brass fittings are on order for these pipes to connect to and will do a little experiment over the weekend to see if by warming they can be gently bent to mimic the originals, in their current form they do bend but it would be nice to tighten up some of the bends slightly to aid installation.

 

[Luke Rickert]

A few years back I found a new friction disk for my 135 on Ebay in the States for not too much (100 or so I think) they must be used in some applications other than the 135.

 

[marcsO]

I think Warner make for all sorts of equipment so guess the version Schaublin use must be the same as many other pieces of equipment, nice find tho

I am at a friends tomorrow and will look at some options around re-finishing the brake, the plan is to use the lathe to machine off some of the material between the metal edges on the electromagnet to get this just below the rim levels, might also nip and clean the edges too. The armature although Warner say don't machine it I will discuss the merits of re-surfacing it on a surface grinder if that is possible, either way its not in bad condition so will see what is what tomorrow when I see the 'expert'.

Tomorrow we are also planning to make a new sleeve for the Variator, this is to replace the one currently on it but also to start the process to upgrade the unit to run on sealed bearings rather than oil lubrication.

Also hope to re-thread the gearbox oil lower discharge feed to an M16 x 1.5 thread to suit the new push fit elbow union which will then join into the 12mm OD pipe pictured above, discharge feed below which is currently M12 x 2, the new push fit elbow is M16 x 1.5 so there should be plenty of scope to adjust this unit to accept the new fitting.



Tomorrow also I will look to open out one of the M14 x 2 holes in the oil tank cap which is the return from the above fitting, again being M14 there should be scope to drill out to get M16 x 1.5, if not will simply drill a new hole in the oil tank cap for the return and thread as required (cap below).

 

[ole.steen]

Marc: Regarding the brake: It is fed DC voltage from a rectifier via an adjustable serial resistor. They all look scorched on the braking surface, but may work perfectly nevertheless. The brake is very nice to have when you are threading against a stop. I made new bushes from delrin, as mine also were worn and chattered.

 

[marcsO]

BRAKE # 3

Ole thanks for the info, also a question on those nylon/delrin bushes, could they be machined from brass as this would provide a more sturdy solution but maybe not as functional - thoughts?

Today as part of the ongoing works on the 135 I did manage to 'clean up' the two parts of the brake assembly on my friends lathe.

The moulded material surface was just proud of the metal poles so machined and cleaned up the poles and recessed the infill material .003" below them, in addition I refinished the armature too so the two would both be freshly machined to give a good contact surface.

Electromagnet before machining:



After:



The armature incidentally is cast so machines a little different to the electromagnet but the result was a nice flat clean surface..

Before:



After:

 

[marcsO]

OIL LINES #1

The new metric M12 x 1.5 x 10mm and M16 x 1.5 x 12mm push fit unions arrived today, having machined the gearbox base drain adaptor to an M16 x 1.5 thread I checked the fit and fortunately it fitted perfectly



I also offered up the M12 fittings to some of the other locations and have to say there may be some issues with space and routing the pipe, the feed up from the pump should be fine as the pipe route can be adjusted to remain well clear of belts and spinning parts etc the same cannot be said for the short feed from the gearbox round to the panel on the back of the machine as this needs to tuck behind the main spindle drive belt and it looks like the fitting is too bulky to allow the pipe to hug the internal castings, either way some jiggery pokery will be required but for now I have the parts and time will tell if the outcome is 100% new system or maybe a 'hybrid' using some old and some new.

Fittings for use hopefully to run the new oil system:

 

[marcsO]

VARIATOR # 5

We started to machine the new inner sleeve which fits inside the central sliding belt mechanism, my version as mentioned in an earlier post had a sleeve which was simply sliding freely inside the sliding mechanism which was not ideal and would not allow is to simply machine seal pockets at each end as was done by another owner (pics posted earlier on his work). We measured up the sliding mechanism and found the internal hole to be slightly cone shaped which means it has worn over time, we machined up a new sleeve in EN19 and got it to where we felt a decent interference fit would work.





We prepared the mechanism in the press and heated it up to around 300º, dropped the new sleeve into it, it went in around half way, after pumping the jack vigorously to take up the slack the sleeve only went in 3/4 of the way before it heated up and the press would not drive it in any more.

The outcome is a sleeve not fully pressed in place sadly. A little annoyed we decided to quit and re-consider the plans, the part will go into the freezer for 24hrs and we hope that as the sleeve is steel and the mechanism is cast the two will shrink at different rates, steel should be more in theory and with any luck the press should push in the sleeve. If not we will have to come up with a plan B.

To be updated................

 

[ole.steen]

Marc!
.003 undercut of the black infill below the poles seems to be right (the manual says .002 to .004). Nice job! I think the bushes should be delrin to avoid clatter and noise. Ole

 

[marcsO]

I might see if I can speak to Warner and ask about this design and see if they can shed some light on the matter.

 

[marcsO]

BRAKE # 4

I spoke with a guy called Chris at Warner UK, he worked for Warner back when they were 'Warner', I think they are now called something different now but he remembers that when the PB825 brake unit was originally made it was fitted with bronze bushes, these over time were replaced with a nylon version as plastic was the 'in' thing back then. He commented that plastic never lasted that well and he suggested if we were to re-make the bushes that doing them in bronze (or even brass but they would be less durable than bronze) would be the way to go.

Still need to be a push fit in the 19mm armature mounting holes but this is something I am going to look into doing rather than make new bushes from nylon or delrin as the durability seems to be a big plus for the unit when fitted with bronze bushes.

In addition he also confirmed that if you reface the armature and re-machine the electromagnetic poles, re-face the infill material to just below the pole surface you will get a fair amount of noise from the brake for a while until the surfaces bed in, this is normal and should be expected.

 

[marcsO]

VARIATOR # 6

The saga continues.........

To recap the design of this part in the 135 series appears to be different from machine to machine, Schaublin have modified the design on many occasions resulting in inconsistent design. My particular machine has a sleeve which sat inside the central variator pulley assembly between the two oil seals, it appears not to have been made as an interference fit like some other machines but a sliding design. This may have been as a result of poor maintenance where the oil leaks caused the operator to tighten the belts too far resulting is excess wear in this area or just that Schaublin modified the design, sadly I wont know the real reason so the project ongoing is to re-machine and upgrade this component.

As mentioned in #5 we drove a new sleeve into the pulley assembly after heating the unit to around 300º, it went in half way but then would not go any further, since this point we tried freezing the parts but this did not work either so the only option was to machine the sleeve out, this is the resulting machined and removed first attempt sleeve....



After successfully removing the sleeve we went about checking in closer detail the bore of the pulley assembly, as you can imagine the findings were somewhat alarming, the hole was cone shaped with a smaller OD at one end, our original sleeve was finished with emery paper to mimic this however we found following more measurement tests that the middle of the hole was 0.2mm narrower than the ends so resulting in a tight spot exactly where our first sleeve jammed up!

I'm guessing this has happened as a result of the over tensioning of the belt following oil contamination and the loads from the motor pulley pulling down on one end of the Variator, and the spindle pulley loads pulley up on the opposite end, either way the only route was the machine the hole back to something closer to a consistent OD, so we machined this out...




After doing this we machined up another sleeve in the hope that this time we would stand a decent chance of actually getting the item press fitted into the newly finished internal 'round' hole.

Machining of sleeve #2





The decision this time round was to also make the insert shorter so that when pressed in the ends would be ready to machine the oil seal pockets into the pulley material with minimal need to machine the new sleeve, a spacer has been machined so that when pressed in the correct space is left for the rebate for the oil seals...

 

[marcsO]

VARIATOR # 7

New sleeve finally in, froze the part and it dropped in with a little help from the hydraulic press so now we have the first part of the puzzle done, next will be machining the twin wiper oil seal pockets in each end of the variator, adding a grease nipple and bleed hole which will be plugged with a grub screw.

The plan is to fill the void between the new sleeve and the shaft (it has a rebate cut into the centre section for this purpose which can be seen in the picture below) with a light grease until the bleed hole fills up and then plug it so the grease remains inside and lubricates the sliding motion of the unit when on the shaft.

The shaft will also be new as the plan is to machine out the yokes to accept bearings so the shaft rotates as a whole in these like the later version of the 135 uses.

Sleeve in place..

 

[marcsO]

OIL LINES # 2

Another small job done which was to drill out the two existing holes in the oil tank filler cap which were the returns from the gearbox and Variator and size and tap to accept the 12mm OD push fit unions.

14.5mm drill followed by a 16x1.5mm tap, did both holes and plan to use one for the return (gearbox only as the Variator wont have an oil feed - hopefully!) and the other can be used as a breather/vent, the inserted pipe will simply rise up inside the corner of the base unit. I also added an O ring to the cap assembly just to reduce/remove and oil leakage from around this area.

 

[marcsO]

Question:

What lubrication/grease/oil etc should this bearing have prior to fitting the casing over it?

 

[marcsO]

Hi is this forum working as I'm struggling to see via the new format look if it is. No indication of views* so you cannot see if threads are being viewed and usually you guys respond to questions with help etc but nothing for a while now - mods whats the situation please?

* re views there is a figure on the thread top but this has not changed in a week which I find strange as normally when posts are updated you do see some views resulting....

 

[marcsO]

BRAKE # 3

As the motor brake is ready apart from the new bronze bushes to be re-assembled I wanted to check the electromagnet was working! Be a shame to have done all this work only to find out it was a dud.

Tested with a 30v DC unit and all seemed fine, a decent pull at this voltage which is good and the amperage was in margin.

 

[rklopp]

Question:

What lubrication/grease/oil etc should this bearing have prior to fitting the casing over it?

View attachment 365723

What is it? Spindle bearing? Oil fed or greased? If greased, Kluber NBU-15 should work. If oil-fed, assemble with whatever oil is supposed to be fed.

 

[marcsO]

Oil fed so will apply the same oil as suggested for the gearbox as this feeds this bearing - thx for the info.