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Unimat 3 - Belt cover removal


 

Hello:

As part of my on-going task (installing a 24v DC motor on the U3) I have come to the point that I need to detach the belt cover from the motor's mounting plate.

Here's the page from the manual showing the whole assembly, which refers to it as the clamping plate:



From the drawing and the corresponding legend, it is clear that part #12 is not one but three parts: the clamping plate and the two pins/screws that make up the pivot for the cover.

As you can see, they are shown as being inserted/screwed from the outside of the cover in.

But I cannot make out any sort of screw head ie: flat head, phillips, allen, etc.
Looking with a loupe and better lighting, I was not able to make out any trace of a screw head.
ie: being this U3 second/third/fourth hand, some indication of a previous owner's haste/lack of patience/sense.

So ...
If not screws, could they they be pins?
And press fit at that?
It would be a rather strange design choice but, given others I have seen on the U3, not impossible.

In any case: anyone here knows how to you get the bloody things off?

Thanks in advance.

Best,

JHM


 

I had a fight with this on mine - the hinges on the cover had broken, and I had a new one to fit. They are just pins inserted into holes in the plate. You can't get them out with the cover on, so the only way to get the cover on or off is to bend it until it clears the pins. Do it on a warm day when the plastic is more flexible, or even warm it in a bath of hot water first. It does feel like the cover will break, but mine didn't.


 

Hello:

Thank you for the prompt reply.
Much appreciated.? 8^)


On Sat, Aug 13, 2022 at 02:34 PM, Keith S. Angus wrote:

... a fight with this on mine ... ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ????????????????????????????????????????????????????????????????????????????????????????? ... had a new one to fit.????????????????????????????????????????????????????????????????????????????????????????????????? ? ?????????????????????????????????????????????????????????????????????????????????? ? ? ? ... just pins inserted into holes ... ?? ???????????????????????????????????????????????????????????????????? ? ??????????????????????????????????????????????????????????????????????????????????? ? ? ? ? ? ? ?? ... can't get them out with the cover on ...
No way!
Absolutely un-be-lie-va-ble.

I tell you, the more things I discover on the U3, the more I think that whoever was in charge of design/quality control was a certified clown.
So much for the famed Austrian industrial quality, just cannot see it here.

... only way to get the cover on or off is to bend it until it clears the pins.
Ahhh ...
As I was not finding any other possible way, I started to look at the possibility of doing exactly that.
But I stopped and reflected: it can't be that, I'll break the cover. There must be a plausible explanation to this problem.

And all this time there I was assuming a previous owner had somehow screwed it up or taken a punch and hammer to it.

In another life, working first tier IT support in a ministry, I put this phrase over one of my monitors:
"Never ascribe to malice that which is adequately explained by incompetence"

This U3 belt cover situation fits like a glove.?? 8^¡ã

... on a warm day ...?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ... warm it in a bath of hot water first.
Thanks for the info and the hot water tip.
If the pins can come off, there may be just enough room in the holes to thread for an M2 screw.
If not, longer tight fitting SS/piano wire pins that can be twisted and pulled out.
That would avoid problems like this one in the future.

I'll post the result when I am finished.

Once again, thanks a lot.

Best,

JHM


 

In nearly every company, you start with a product designed by engineers. As that product is successful, and the company makes money, the accountants take over, and try to cut expenses to the bone, while still producing a salable product. And eventually, they cut past the bone, and the product stops selling, and the company goes under. Some companies have so many products going out that the progression lasts a really long time, and a very few may survive it...? Not sure EMCO is one of them.?

Bill in OKC

William R. Meyers, MSgt, USAF(Ret.)

Aphorisms to live by:
Good judgement comes from experience. Experience comes from bad judgement.?
SEMPER GUMBY!
Improvise, Adapt, and Overcome.
Physics doesn't care about your schedule.
The only reason I know anything is because I've done it wrong enough times to START to know better



On Saturday, August 13, 2022 at 01:16:36 PM CDT, <sawbona@...> wrote:


Hello:

Thank you for the prompt reply.
Much appreciated.? 8^)


On Sat, Aug 13, 2022 at 02:34 PM, Keith S. Angus wrote:

... a fight with this on mine ... ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?? ????????????????????????????????????????????????????????????????????????????????????????? ... had a new one to fit.????????????????????????????????????????????????????????????????????????????????????????????????? ? ?????????????????????????????????????????????????????????????????????????????????? ? ? ? ... just pins inserted into holes ... ?? ???????????????????????????????????????????????????????????????????? ? ??????????????????????????????????????????????????????????????????????????????????? ? ? ? ? ? ? ?? ... can't get them out with the cover on ...
No way!
Absolutely un-be-lie-va-ble.

I tell you, the more things I discover on the U3, the more I think that whoever was in charge of design/quality control was a certified clown.
So much for the famed Austrian industrial quality, just cannot see it here.

... only way to get the cover on or off is to bend it until it clears the pins.
Ahhh ...
As I was not finding any other possible way, I started to look at the possibility of doing exactly that.
But I stopped and reflected: it can't be that, I'll break the cover. There must be a plausible explanation to this problem.

And all this time there I was assuming a previous owner had somehow screwed it up or taken a punch and hammer to it.

In another life, working first tier IT support in a ministry, I put this phrase over one of my monitors:
"Never ascribe to malice that which is adequately explained by incompetence"

This U3 belt cover situation fits like a glove.?? 8^¡ã

... on a warm day ...?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????? ... warm it in a bath of hot water first.
Thanks for the info and the hot water tip.
If the pins can come off, there may be just enough room in the holes to thread for an M2 screw.
If not, longer tight fitting SS/piano wire pins that can be twisted and pulled out.
That would avoid problems like this one in the future.

I'll post the result when I am finished.

Once again, thanks a lot.

Best,

JHM


 

Replying to all: if the Unimat 3 is so awful, go buy a Sherline and stop complaining.


 

Hello:

On Sat, Aug 13, 2022 at 03:16 PM, @juliushenrymarx wrote:

... post the result when I am finished.
Here we go:

Keith's hot water method worked a wonder.
I was terrifed the cover would break, but as the pins are shortish the plastic did not have to stretch too much.

These pins are 3.0 mm and are a press fit in the plate that is 4.0 mm thick.
Here is the pin hole and how a 3.0mm drill fits snugly in it.



The plate being 4.0mm and the hole being 3.0 mm leaves a bare 0.5 mm for threading all around.
Fortunately I have a Greenfield set with a 3.5x0.6 tap/die combination which is rather rare as the usual I see (when I see it) is 3.5x0.5.

I was able to tap the holes with just enough threads to be able to put a screw in as the hole is not too deep and I don't have a snubby 3.5x0.6 to get to the bottom.

The threads bit and in doing so actually caused the thin wall to bulge.
But it is not an issue as the screws are not actually holding anything, they only have to stay put and act as a pivot.

I did not have 3.5x0.6 screws so to get by for now, I made ~ 5.0 cm of thread to make the two set screws I was needing.




?
Next week I'll get a couple of proper 3.5x0.6 screws, cut the heads off and dremel in a tidier slot.

@ Keith: thanks again, you saved the? day for me.? 8^)
@ John: thank you for your input.
But there's really no need to get your nickers in a twist over my post.
My opinions are just that: my opinions, to which I am entitled. Just as you are entitled to yours.
Mine are solidly backed by over four decades of professional activity in my specific field which, BTW, include design and QC.
Do have a good day.? 8^)

Best,

JHM


 

On Sat, Aug 13, 2022 at 11:59 PM, @juliushenrymarx wrote:
Keith's hot water method worked a wonder.
Glad it worked, as I never actually tried it! I just reasoned that the only way they could have got the cover on was to stretch it over the pins, so that was the only way to get it off. It did not occur to me at the time to try a bit of heat.


 

Hello:


On Sun, Aug 14, 2022 at 02:53 AM, Keith S. Angus wrote:
... only way they could have got the cover on ...
Don't think so.
It is (apparently) the only way to get the cover off.
At the factory they would not be doing something like that, complicated and rather manual intensive.

I think that the job was probably done by putting the clamping plate in a holding jig with the plastic cover in position.
Then the pins were put/held in place and pressed into the holes.

Best,

JHM