Frezka TOS FA2V stůl

[Broer]

Ahoj,

Obnovuji frézku TOS FA2V a při sestavování stolu narazím na určité potíže.

Když jsem dostal stroj byl kompletně rozebrat a myslím, že některé části chybí.


Všiml jsem si, že o tomto stroji je mezinárodně známo jen velmi málo; což ztěžuje montáž...

Téměř všechny problémy jsem se setkávají mít co do činění s pohonem stolu.

Na fotografii vidíte aktuální situaci. Na základě toho několik otázek:

1 - Mám jen jednu bronzovou matici a jsou tam dva otvory (označené zelenou a žlutou). Myslel jsem, že by to měly být dva, ale jen jeden.

2 - lathes.co.uk říká, že tabulka může pohybovat 640 mm. To na mě v žádném případě neplatí, protože (zeleně označené) nit těsně přiléhá a dosahuje bronzové matice… 
Jak se může stůl pohybovat o 640 mm, když jsou závit 68 cm a vzdálenost mezi dvěma maticemi je 35 cm? 
68 - 35 = 33 cm pohyblivý. Co jsem chybí?

3 - Jak vypadá ozubené kolo, které by mělo klouzat po závitu vřetena? (Modrá na fotografii.) Tato položka není u mě součástí. Fotky by byly velmi užitečné.

4 - Jeden z klínů v ose Y nezapadá. Zdá se mi, že je příliš hubený…???


Zkrátka a dobře, já chci vědět, co původní vypadá a jak se musím dát dohromady.


Pokud mluvíte německy nebo anglicky, velmi bych ocenil odpovědi v tomto jazyce.


Díky předem / Dank im voraus / Thanks in advance

[zverodoktor]

Hi Broer,
maybe manual of this Milling machine will be helpful for you.
http://www.tumlikovo.cz/download/
Search file " MANUÁL KONZOLOVÝCH FRÉZEK FA2 (H, V, U)"

Best regards, Andrej.

[Broer]

Hi Andrej,

Thank you for your reply!

Very useful website. I checked out the document you proposed, and found some information that comes in handy for me. But I couldn’t find information concerning the table drive.

Though, this manual is definitely worth reading; thank you.

Kind regards,
Broer

[zverodoktor]

Dear Broer,
You're welcome!
I mean, that your configuration is wrong. I mean, that bronze nut must be in the yellow holder. At green one is missing gear wheel drive which transfer movement from blue gear to the threaded rod via slot visible at front part of geared rod in your photography. But, maybe I am wrong.
In this thread one guy dismantle similar, but bigger (and littlebit more complex) milling machine (korean version of TOS FA3 mill). There are also photographs of milling table guts.
viewtopic.php?t=23188

[titel]

Hi Broer.

I am no sure if I have same model as you. If no, at least you can compare this two models and you will find answer for some your questions.
1. There should be only one nut. Second housing is for driving screw. There is a simple nut with no backlash compensation.

2. If there is one nut, table can move 640mm.

3. Now I realize that you have V (vertical) model and I have U (universal) model which have tilting table. Thats why my milling machine have driving gear in the middle. I have also H (horizontal) model which have same table as you, but I don't have any pictures . So try to find information about the H model as well.

4. Sorry, I cant help.

With regards
Rado.

[Broer]

Hi all,

OK, I get it. I moved the nut (see photo). Now I have 640 mm table movement, indeed. 
I just didn’t thought that there would be no compensation for backlash… Maybe the friction of the large table key helps in preventing the table to „walk away” during milling.

_______

@Zverodoktor

I didn’t knew that thread yet. But indeed, I see that there is only one nut there. The other one has a key only; no threads.
_______

@Rado

Yeah, perhaps I can find something on the FA2H. That helps!
You did a very nice painting job on your mill, by the way.
_______


The first two problems are solved now. Thank you guys!

Two questions are still open: the keys, and the gear.

[titel]

Hi.
If there is a backlash between screw and nut, you cannot use climb milling. Friction doesn't help.
The only way is use conventional milling - up milling.

And now the keys.
If there is a gap (and there is), you can stick on the opposite (not functional side) a sheet of bronze. Of course thickness must be little bit over the gap. Also calculate the thickness of the glue.

[zverodoktor]

Hi,
congratulations! As mentioned by Rado, you must glue some sheet material on back side of your wedges. It is, of course, possibble to use bronze sheet, but there is often problem with flatness of glued material. You can scrap bronze sheet after gluing to flat, but it is also possibble to use as underlay for the wedge other better formable sheet materials, for example PRESSPAN. It is special hard resin impregnated carton paper used often as electric isolator and it is available in different thicknesses. It is easy to glue it by epoxy glue. When you press it through gluing process to the wedge by flat sheet of glass, you will have smooth and flat surface immediatelly. Dont worry about durability, is absolutelly suficient for this purpose.

[Broer]

@ Rado

„you cannot use climb milling” Maybe I have to start looking for a new nut…

Yes, of course. I was hoping they weren't worn, and that I just put them in the wrong way (like with the bronze nut).
But yes, I have some bronze sheet material laying around.

Thank you!
______________

@ Andrej

That’s a surprising trick! I didn't know that one…
Thank you for sharing it.
______________

It’s just a bit strange to me that at the short wedge, I can stills see something of the original scraping, and at the long wedge, it seems to be worn away.

Is asymmetrical wear normal?

[titel]

Hi Broer.
I don't have good news for you
New nut often doesn't help. You have to unify also the screw, because also screw is not were out symmetrically.
But after some time you will have the same problem as today. I think that only way is to make nut (2nuts) with backlash compensation. But then you will lose travel length a little bit and make some other minor problems....
I don't think it's worth the troubles. When you understand all errors of your machine, you can produce good results.
You can live with that.
Rado.

[titel]

Hi.
I was looking at that picture and it seems that on right side the wedge can go deeper or not? The hole for screw is deep enough isnt it?
R.

[Broer]

Hi Rado,

That's a very good point. It can go deeper there; I was thinking the same...

The big hole is deep enough, but the M8 threaded hole isn't, so I was thinking to just shorten the screw. Now it has about 40 mm of M8 threads, but when I make it 25 mm, it should fit.

About the nut:

I think you're right.
For now, I continue with the single (worn) nut. If it turns out that it works too bad, I can try to make a backlash compensation.

First, I'll take care of the wedges and the table feed gear.


Broer

[Broer]

Hi all,

The wedges are both in place now. I machined a special screw so that the wedge fits in correctly.

I have two further questions. Maybe you guys can answer them.

1- It’s an all too basic question, but I’m not 100% sure… The push buttons below the table feed lever; are they for activating the spindle motor, or the table feed motor?
Should the user select the feed direction with the lever first, and then switch the motor on? Or should the motor run before selecting the feed direction?

2- The machine came with some old collets for the ISO40 toolholder. I would like to purchase some additional collets, but I don’t know what type it is (see picture). Does anybody recognise this type?

Thank you so much, again…


Kind regards.

Broer

[titel]

Hi Broer.

1. These buttons are only for spindle motor. Table feed works like this:
Level has 2 positions on the left and 2 positions on the right. First position engage normal feed speed (selected on gearbox on the left). Second position (this position is not fixed and will return to first position when you release the lever) is for fast table moving.
Depends on electric wiring, fast moving can be use with or without spindle motor running.

2. I wouldn't do it and I would order ER collet holder and collets.

Rado.

[Broer]

Thank you for sharing your knowledge, Rado.

So the lever takes care of the mechanical clutch engagement, and at the same time the electrical activation of the feed motor. But does this happen at exactly the same moment, or does the lever activate the motor first, and then, moving the lever further to „the first click”, engage the clutch? (for reducing the starting load, for example?).

What do the switches and buttons on de side of the machine do, by the way? One switch is obviously for coolant…

And yes, ER collets would be great.
I’m still interested in knowing the collet-type, since there are only a few sizes missing; it would be a cheap beginners solution.


Broer.