Author Topic: Mini Knee Mill Recommendations (Read 33815 times)

sparky961 · « **on:** January 11, 2012, 12:28:41 PM »

Although I've learned a lot of new ways to use my machine over the past few years, I still have the desire for a vertical knee mill. I don't, however, have the space for a full sized one.

Can those of you with mini knee mills speak to their pros and cons? Other opinions on this style vs. others? Maybe it goes without saying, but I would like versatility, rigidity and compact size.... yes, the best of all worlds.

The sort that I'm thinking of would be something like this:
http://www.grizzly.com/products/Vertical-Mill/G3102

Thanks!

-Sparky

Dale · « **Reply #1 on:** January 11, 2012, 05:05:22 PM »

i have had my mini knee mill for about 2 years and can say its a good bang for the buck. I bought mine from Discount Tools and arrived on time. I installed dro's on all 3 axis and haven't looked at the dials since for they read in thousanths and millimeters easy for me to mix up. Its quiet,and very rigid for its size, the work lite failed but that gave me a reason to make one better. The mill I got has handy lifting holes to assist in setting it on its stand and makes a great spot to mount the collet rack and dro's without drilling into the machine. If you work within its parameter's its a great machine

doubleboost · « **Reply #2 on:** January 11, 2012, 06:37:13 PM »

Very pleased with mine
Made a riser block and tweeked a bit more travell
For the money a great machine
http://finance.groups.yahoo.com/group/6x26millingmachines/
loads of information on this site
John

sparky961 · « **Reply #3 on:** January 11, 2012, 09:15:43 PM »

Quote from: doubleboost on January 11, 2012, 06:37:13 PM

Made a riser block and tweeked a bit more travell
For the money a great machine
John

A riser block? I'll read more at the link you sent, but this one confuses me... why would you need the riser block when you have the knee? I figured I'd be getting away from using the one that I have now.

j_e_f_f_williams · « **Reply #4 on:** January 12, 2012, 12:26:11 PM »

Hello,

I have an 8x30 mini-knee mill that does not have a stand but goes to the floor with a smaller built in stand (kinda). I think it has more distance between the table and the spindle compared to the one you picture.

I added a DRO to 2 of the axis (have the 3rd but have not installed it yet) and a 3HP DC treadmill motor for variable speed up to 3000RPM (can go to 4000 with a belt change but not tried it yet)

Been happy with it over all. Not sure of the real brand as this was a left over brand new mid-1980's Taiwan mill that was left in a basement of the importer. He was selling off 4-5 of them that were left over. Still was covered in the waxy/oily goo when I got it for $750.

(first photo inclusion so ... we will try this ...)

This was the delivery back in 2007.

From when I have been to KBC Tools it's very similar to their mill other than mine is manual lube.

TTYL, Jeff

sparky961 · « **Reply #5 on:** January 12, 2012, 12:52:21 PM »

Hey Jeff, where the heck do I get one for $750??

doubleboost · « **Reply #6 on:** January 12, 2012, 02:15:39 PM »

Hi
Sparky
It all depends on what you are making
A decent rotary table and a chuck leave very little room for a job and tool
Personally i would go for a R8 spindle (loads of bridgport tooling to be had)
John

j_e_f_f_williams · « **Reply #7 on:** January 12, 2012, 02:19:18 PM »

A time machine to 2007 and a visit to Mississauga (west end of Toronto Canada)

It was kinda funny ... the importer's family also had a variety store and these were in the basement. So I went to a variety store to buy a mill ... wandered down the back stairs and there was several mills and a couple of 14x40" lathes.

The importer about the manually winch it up out of the basement

My 'winch' was a bit less manual ... good to have an uncle with a crane on his truck

TTYL, Jeff

j_e_f_f_williams · « **Reply #8 on:** January 12, 2012, 02:23:59 PM »

Hello,

To go with what doubleboost stated.

I have a 6" vise and 8" rotary on the table of my mill all the time. The rotary table I can only get 3/4 of the surface under the spindle as it's at the end of the table travel. But I have lots of room with my mill for tool changes etc with the knee.

If you want the specs I can gram them from the pamphlet the next time I am out in the shop.

And my mill has R8 spindle ... as all of the current 6x26 or 8x30 mini-knee mills ... or so I thought.

TTYL, Jeff

cjoscelyn · « **Reply #9 on:** January 15, 2012, 07:35:57 PM »

I have had a 6X26 for about four years now and I am very satisfied with it, after making several mods. I think the main reason these mills are not as popular as they should be is because of the, as delivered, rather small work envelope, compared to table size. I have a Harbor freight model, the cheapest available in the United States. As delivered the X=15", Y=6 1/2" and Z=12". The current envelope is: X=20 5/8", Y=8 3/4" and Z=18" with a 6" riser added. I believe I could have extended the X travel to 22" in hind sight but I have had no need for the travel I have now. The Y mod was the best choice as it allows me to machine an edge of the table, something you can't do as the mill is delivered. . I have some pictures on the Yahoo groups that show how the mods were done. I have also added 3 phase/VFD drive system, 3 axis DRO, X power feed and a "tachulator" that can show SFM- a real end mill saver. With all of the mods I have less than $3,000 US invested.

sparky961 · « **Reply #10 on:** January 15, 2012, 10:48:50 PM »

Where does the riser block go? Is this something that raises the head up more, or on the table? Something mounted to the table is what I think of when someone says "riser block", as I'm constantly bolting and unbolting mine from the table to account for different tooling lengths.

cjoscelyn · « **Reply #11 on:** January 16, 2012, 07:30:00 PM »

The "riser block" is installed between the flanges between the top of the column and the milling head. I have attached a picture of the one I made and installed.

sparky961 · « **Reply #12 on:** January 16, 2012, 10:20:52 PM »

Thanks for the picture. I get it now. With the block installed, how close to the spindle can the table be raised? Is there any noticeable reduction of rigidity?

The biggest issue for me is probably in getting it into the basement. It would have to go through the front door, around a hairpin turn, then down a flight of stairs.

Can someone who's taken one apart give me an idea what the heaviest piece weighs, and how long it takes to break down and reassemble?

Much thanks..

-Sparky

russ57 · « **Reply #13 on:** January 17, 2012, 08:05:41 AM »

i took mine down a long steep garden path. Supplier helped dismantle, the head/turret comes off easily, and the table. We left the knee on.
I reckon the body was then 150Kg odd. Took an hour or so to dismantle, and a couple or three to put back together by myself. (help to put the head back on, but table etc was solo). pretty straightforward, wash all the goo off while its apart. eventually no bits left over! (took a while to figure out a spare ball bearing, came out of a lock screw hole)

regards

russ

Davo J · « **Reply #14 on:** January 17, 2012, 08:51:57 AM »

It is a good idea to take these mills apart and give them a good clean. They all have some machining grit left behind, and is the only way to get rid of all the rust preventive from shipping.

Dave

mnmetal · « **Reply #15 on:** January 17, 2012, 10:36:17 AM »

You may want to consider the slightly larger 8x30 Grizzly.

http://www.grizzly.com/products/8-x-30-Vertical-Mill/G0730

It is about $800 more though.

doubleboost · « **Reply #16 on:** January 19, 2012, 04:46:10 PM »

Hi
I put a 5 inch riser block in mine it made no difference to the rigidity
When the machine is dismantled 2 people can lift the bits (just)
The main casting is the heavy bit
When i bought mine i had to strip it down and carry it out of a garage that had been built around it , down some stairs
I spent a couple of days cleaning and reassembling
Most of the cap head bolts were replaced bearings re greased etc
It seems you are buying a kit of parts that need putting together properly (very satisfying once done)

John

WillieL · « **Reply #17 on:** January 19, 2012, 05:36:19 PM »

Quote from: sparky961 on January 11, 2012, 12:28:41 PM

Although I've learned a lot of new ways to use my machine over the past few years, I still have the desire for a vertical knee mill. I don't, however, have the space for a full sized one.

Can those of you with mini knee mills speak to their pros and cons? Other opinions on this style vs. others? Maybe it goes without saying, but I would like versatility, rigidity and compact size.... yes, the best of all worlds.

The sort that I'm thinking of would be something like this:
http://www.grizzly.com/products/Vertical-Mill/G3102
Thanks!

-Sparky

I hope you have better luck with Grizzly than I did Sparky. Back when I was shopping for a mill I was looking at the very same thing for the same reasons. I called them several times trying to locate of the those mills and they kept telling me they didn't have a single one anywhere in the country. I guess they got tired of me asking and finally told me they the didn't know if they would ever get any more.

In the end it worked out for me though. A few days later I found a new 8x36 Bridgeport clone on sale for the same price Grizzly wanted for their 6x26. Hopefully they have managed to import some more by now and build up their inventory.

Willie

mnmetal · « **Reply #18 on:** January 20, 2012, 07:08:34 PM »

John,

Is that riser you made steel or aluminum? Either way that's a good sized chunk of metal. Not cheap.

sparky961 · « **Reply #19 on:** January 20, 2012, 08:58:47 PM »

Quote from: mnmetal on January 20, 2012, 07:08:34 PM

John,

Is that riser you made steel or aluminum? Either way that's a good sized chunk of metal. Not cheap.

Steel is the cheapest part of anything made of steel. Trust me.

Again, many thanks for everyone's input here. Any idea what one of these machines should cost used? I've been seeing them in around the $2500 CAD range, though a few posts I've seen here and there talk about new ones for like $1300. What am I missing here? Maybe that was in British Pounds??

-Sparky

doubleboost · « **Reply #20 on:** January 21, 2012, 06:17:51 AM »

The riser block is made from steel
not sure what sort but it was tough
John

Davo J · « **Reply #21 on:** January 21, 2012, 06:40:58 AM »

If you can weld you could pick up a piece of heavy wall pipe and weld plates on either end. Also you could use long studs or thread rod that go right through the spacer instead of having separate bolts top and bottom, so that would exclude the slots in the sides.
When looking for chunks of steel check your local scrap yard (become friends) and ask them to keep an eye out for you. It's amazing what some workshops throw out because it has been laying around for a long time with no use.

I have the next size up mill which is like the 3617 from grizzly and even it lacks room between the spindle and table. I have a plan for a riser for it, but with having the horizontal spindle in the column and the arbour on the ram it makes it a lot harder than just putting a spacer in like you can do.

Dave

mnmetal · « **Reply #22 on:** January 21, 2012, 06:26:28 PM »

Quote from: Davo J on January 21, 2012, 06:40:58 AM

If you can weld you could pick up a piece of heavy wall pipe and weld plates on either end. Also you could use long studs or thread rod that go right through the spacer instead of having separate bolts top and bottom, so that would exclude the slots in the sides.

Dave

Dave,

I was thinking the same thing. Look for some thick walled pipe and weld some flanges on it.

I'm considering the Grizzly 8x30 mill as a backup plan just in case getting one from China falls through.

Ed

WillieL · « **Reply #23 on:** January 21, 2012, 07:43:55 PM »

Quote from: doubleboost on January 21, 2012, 06:17:51 AM

The riser block is made from steel

John, what would you estimate the weight to be on your block? Do you notice any difference in dampening out any vibrations or chatter on the machine now?

Xldevil · « **Reply #24 on:** January 22, 2012, 03:53:16 AM »

Hello.
Is there anyone who made a working drawing of that riser?
The one on yahoo-group is wrong.
Or,maybe someone is selling such a riser.My lathe is really to small to turn my own.
Cheers,Ralph

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Author Topic: Mini Knee Mill Recommendations (Read 33815 times)