Hello - & I have a question about Amoloco Milling Attachement

Hello,

I've been on this forum a while and found it to be very helpful. There sure are a lot of knowledgeable folks on here.

I'm interested in learning machining skills, for no other reason than self improvement. I dont have a particular interest in model making - may be that comes later.

At the moment my skiils are pretty basic and I make lots of mistakes. Most of my projects come out looking as if gnawed from scrap by a demented owl.

Anyhow. In a moment of madness I recently bought an Amolco mill of dubious provenence. Of course on inspection it has a runout of about 4-5 thou. I have pre-loaded the bearings as much as I dare. So I'm thinking the bearings might be shot and need replacing.

On dismantling it I found that it is fitted with Steyr 302050C Taper bearings - which ~(I think)~ are metric?

Does anyone know if these are the correct bearing type? Seems strange to me that a metric bearing would be original fit?

Thanks in advance

Rich

Hi rich Steyr do make imperial seized bearings you can contact a local suplier and they can give you a comparable bearing it dosn' t matter what make just the correct size and type. Perhaps you can check the spindle for runnout , concentricity or bend whilst it is out use a pair of v blocks and a dial test indicator ?

David

How did you measure the runout? Unless you have a known good MT2 tool that you can fit in the taper socket, the only way to be sure is with a finger type DTI running on the inside of the taper socket. If you measured it with a taper tool in there might be a bit of grit or a "ding" on the inside surface of the socket.

Hi

Good question. I've measured the runout on my lathe spindle using an MT2 collect chuck and test bar ( home turned) and its less than 5 tenths If I then transfer that same chuck and test bar to the milling spindle I get over 4 thou. But, you are right that it could be that the taper in the Mill has a ding, it doesn't look great and there was some obvious rust in there when I first got it.

What are the options for fixing a damaged MT2 taper? Assuming the worst and its more then just a bit of grit in there. I gave it a good squirt of brake cleaner and a wipe out before testing.

I will remove the spindle and check for concentricity using v-blocks. That will confirm/deny another possibility.

am still a bit puzzled as to why it has metric sized bearings fitted.

You need an MT2 taper reamer, just give it a very gentle touch, not under power! If you insert the reamer with a lot of oil and carefully turn it you may be able to feel as any ding catches a flute and gently cut it away.

Why not metric bearings? When you say Amolco mill, is it just the head or the complete thing with base? What colour is it? The original Amolco was make by A Mole and Co in Watford and painted crackle grey, but later the design was resurrected for a while and made by a company in Baldock whose name I've forgotten, but they painted it crackle blue. I had an old style Amolco grey head and bought one of the bases from the second company so my machine was bi-colour! But the point is that the later machines were being made in the early 90s and the company would quite likely fit metric bearings - and the base I bought had metric feeds. Indeed even Mole may have fitted metric bearings.

I thought the machine was rather nice though too small for me, and I wanted something that had a quill feed for drilling. I did make a couple of modifications to increase the working height range, fitting a new longer key to the back of the column and an extension on the top with a longer and metric feed screw. You also get more height range by using MT2 finger collets, either Myford style with a closing nut or drawbar type rather than a collet chuck.

Thanks again for the advice on the MT2 Taper. Will proceed with caution.

I have the crackle grey painted model, made by Mole in Watford. Just the milling head, no base. It just seemed to me that an imperial size would be more likely. But thats just my unfounded assumption could just as easily be metric as original.

The lack of quill for drilling does make progress somewhat slow, but I don't have space for a separate machine so i'll have to live with it for now.

But I can def. see why you upgraded.

Have tried plain MT2 collets but they would not hang on to the tool securely even with a drawbar. An end mill would work its way out? Is there a way to stop that ?

If the taper is good an mt 2 collet will hold, but the drawbar must be tight - this is likely the machine saying my taper is bad.

In other words it's the same fault 

Edited By Dave Halford on 27/02/2018 20:37:46

Thanks everyone for your kind advice - good stuff.

Seems like the taper is the likely issue so I'll go and give it a good clean out.

Then if problem persists after clean I will *carefully/gently apply a 2MT reamer.

As this was a new member intro thread, will start another one when I report back - hopefully with good news

Take something with a good MT2 on it and scribble marker pen all over it. Insert it in the spindle and gently turn it a little. Remove it and look at how the marker pen ink has been scraped off. If it's removed over a large majority of the surface, it's OK. if you've only got localised contact, the spindle has issues which if not too severe, a taper reamer will deal with.