Blowing Diodes On My 10EE

cbrcliff · Mar 18, 2011

Good Evening all,
I'm the new proud owner of a 1980 10EE in great mechanical condition but it seems to be blowing diodes in the black box. Can someone point me in direction to start my troubleshooting ? I'll keep sifting thru the threads to see if someone had the same problem.

Thanks
Cliff

rke[pler · Mar 18, 2011

Which diodes?

cbrcliff · Mar 19, 2011

The ones in the black box.

PaulM · Mar 19, 2011

You need to give the people here more specifics. Which diodes in the black box blow - hope its not all 14 every time :eek:

the people here will be extraordinarily helpful, but you need to give as many specifics as possible.

Different ones will indicate different things.
here is a picture I had from when I opened that area up.

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Paul

cbrcliff · Mar 19, 2011

Sorry about that. I'll break open the box to tell you which ones are blowing. I was just going off what the seller said and I thought it might have been a cookie cutter problem.
Is this some type of motor controller?

Here is a pic of the black box. They replaced the diodes so I'm not sure which ones blew. The pic shows the blast zone though.

Also the right hand main fuse in the same access panel is blown too of the three in the upper left hand corner.

Cliff

PaulM · Mar 19, 2011

OK - I think from what you have written that you are going to have to do some investigation first. The way I read your message, the diodes were blown (and replaced) by the previous owner, and several of the main fuses are also blown when you received the machine? Are you just operating on what the seller told you?

To a search on Modular and diodes and you will find lots of info, also try searching on modular and blown fuse. This may give you some more info to start your diagnosis. Also read Donnie's posts if the drive has been "worked on" you may want to trace wires to confirm its hooked up as its supposed to be.

If you don't have the manual for your specific machine from Monarch - order it as it will have the specifics for how that machine was built. If it was blowing fuses - you may want to get a couple and you may also want to buy some diodes (in your search on diodes you will find plenty of info on using replacement diodes that cost a few cents each rather than $$ for the type that are there now).

Once you do some checking Russ and others can be really helpful.

last thing - do you own a decent multi-meter? You will likely need one.

Paul

donie · Mar 19, 2011

Cliff,
I will get you in the right direction starting right here.

Looking at your diodes.
The fourth one over from the left, is jammed in the clip, "wrong polarized", It actually damaged the clip, "spread it open".
Also, that style of diode has the problem of the diode wire ends being crimped into the cap instead of soldered like later Monarch diodes.
After decades, they loose contact and also get weak "leak back".

I would replace all the diodes right off. I use 600v 3amp diodes, that I make brass ends for, like this.

Monarch EE lathe control module picture by donsmonarch10ee - Photobucket

Others may say different, this is what I found works best.
You have a nice machine, of the vintage that I am only interested in, very serviceable. and when working unmatched performance.

You have to count on sorting out what others have done.
When confronted with a machine like that, I go through absolutely everything, every wire, every switch "contacts, very important".
You must have the electrical prints, for your machine.

After all, who would sell such a machine in working condition?

cbrcliff · Mar 19, 2011

Thanks Paul.
I did go off of what the previous owners told me and it was hard to nail down when this started occuring. The machine has been sitting broken the last 10 of its 30 years of life. They bought the machine new in 1980.
The last time they had it worked on was back then and I'm not sure what the Technician did to start this problem (if anything at all).
The previous owners told me that the machine would run for a short time (1 minute or so) with the new diodes and they would blow again.
I have not run power to it yet.
I did look at all the wiring and it looks extremely unmolested.

Also, I did get the manual with the wiring schematics and I have a decent meter.

Thanks again for your help.

C

donie · Mar 19, 2011

Looks good.
Inch/metric gear box is a nice touch.
I run two such machines.
The weak links are the diodes, the Square D switch contacts, and the C3j field tube.
It important to have a strong C3j tube, it works over time with the diodes, that control the drive functions.
The machines tend to take an hour to warm up, the module adjustment should be made when the machine is at temp.
Those adjustments are top speed. and speed comp.
I would suggest not running the machine over the ability of the comp circuit to maintain speed.
Clean the filter in the left hand compartment often.

rockcombo · Mar 19, 2011

cbrcliff said:
Donie,
A German company came in and bought out this small company in Huntsville AL. This company still has 6 Hardinge DSV's in perfect condition which they still use. A new manager walked through the shop and wrote "scrap" on the machines they wanted to get rid of.
Here is a pic. I almost fell over when I saw that. The guys in the shop couldn't believe it either. They almost didn't let me go...

Anyway, I really appreciate the advice. This was completely an impulse buy. I've been looking hard for 6 months and have had 2 bought out from under me. I guess they weren't the right ones..

I should have paid my mortgage instead I guess. I'm only 2 months behind though so...

you will be really glad when you get it running that the others fell through

, the I/M 10ee is one of the finest machines of it's size , I blew my budget to get mine and have no regrets .
Brice

cbrcliff · Mar 22, 2011

I called monarch tech support and they told me to check the speed control pot and sure enough it is bad. It's never been replaced. I'll let you know what happens...

rke[pler · Mar 22, 2011

cbrcliff said:
I called monarch tech support and they told me to check the speed control pot and sure enough it is bad. It's never been replaced. I'll let you know what happens...

How did you diagnose it?

cbrcliff · Mar 22, 2011

I bought a decent Meter with an OHM readout on it. I checked both ends on the top pot with 3 wires and got an open reading. I then checked the wiper and one end and I got a closed reading. I checked the wiper to the other end and got an open reading. The lower pot seems to be working fine. I got my info from this video.

YouTube - How to test a potentiometer

rke[pler · Mar 22, 2011

cbrcliff said:
I bought a decent Meter with an OHM readout on it. I checked both ends on the top pot with 3 wires and got an open reading. I then checked the wiper and one end and I got a closed reading. I checked the wiper to the other end and got an open reading. The lower pot seems to be working fine.

Sounds OK, but I usually take it out of the circuit to make sure of the reading. In this case the armature pot ends are across a bridge rectifier and will read normal with one DC bias and "shorted" in the other, the field pot will read the sums of the resistances between the pot and the "max speed" pot (both in case the module is not removed).

cbrcliff · Mar 22, 2011

I'll do that first then.... So I did.

I did get the same reading after cutting it out (thankfully!)

OMG The thing is roll pinned together. A lot of the machine has roll pins!

I might need some guidance on replacement. Is there a past post I can refer to?

Cliff

steelz · Mar 22, 2011

What about running the machine without the Module? That's the first step to see what you have. You can damage a lot of parts in the module fooling around with the wiring in other places on the machine. If the machine run without the module then you have a starting point.

Every one of these I've fixed the transformer wires were crunchy and shorting. That will take out the fuse. Something to think about if the machine dies when the light glows and you push that button to fire the transformer then poof, blown fuse.

Good luck. Like the others said a very straight forward and simple machine once you fix the first one.

rke[pler · Mar 22, 2011

cbrcliff said:
I might need some guidance on replacement. Is there a past post I can refer to?

Are you asking about getting to it mechanically or finding a functional replacement? If it's the latter then the only real source (other than scrounging here and other sources) is Monarch. The pot is either a 20K pot or 100K Clarostat wire-wound pot with half of the turns shorted - the last half in the case of the armature pot (giving 50K change in the first half of travel) and the first half in the case of the field pot (resulting in 10K change in the last half of travel).

cbrcliff · Mar 23, 2011

I have not run power to the machine yet. I was hoping to fix whatever was wrong first. I wanted to fix the problem first. I'll run power to it when i fix the speed control.

I sent the speed control casting assembly off to Monarch. They will replace the pot for around $300.00.

I'll take it! I don't want to deal with those tiny roll pins.

cbrcliff · Apr 11, 2011

Bad Speed Control Follow Up

Well I got the speed control assembly back from Monarch about a week ago and finally finished installing it and the machine works perfect! It cost $140 for the part and the installation of it. Buying that machine was the best $1500.00 I ever spent...

YouTube - P4100390.AVI

rke[pler · Apr 11, 2011

cbrcliff said:
Well I got the speed control assembly back from Monarch about a week ago and finally finished installing it and the machine works perfect! It cost $140 for the part and the installation of it.

Good deal!

Buying that machine was the best $1500.00 I ever spent...http://www.youtube.com/watch?v=QCOAc3TG9ig

If you ever want to double your money I'll take it off your hands...

Blowing Diodes On My 10EE

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