Info on 1980's ACRA mill?

[PNW_Guy]

I have an ACRA model CK-4HK knee mill and I'm trying to find any documentation on it. The motor plate says 1980, and I assume it's the original.

I'm trying to find any printed documentation I can find. A parts diagram would be awesome. I don't really need a full manual (I know how it all works) but some specs would be good.

I called and emailed ACRA. They are beyond useless. Based on my phone call (a guy yelling at me to email my question) and the lack of reply to my email I'd never consider buying new ACRA equipment. vintage-machinery.org doesn't do imports. A Google search only brings up machines for sale and a few links to Acer tools.

I'm assuming ACRA didn't make it, and just put their name and paint color on something. Any idea what company would have made it?

It's a great mill and has all the things I think are important - big table, 3hp, X power feed, mechanical variable speed, quill feed, tilt and nod adjustments on the head and it came with a rotary phase converter. It seems to be accurate - I drilled and reamed a .499 hole and can't get a .500 pin into it. After tramming, I used a large face mill and got a beautiful pattern with no oddness. I know some of the history, and it was purchased used in the late 80's by a retired machinist in my area, who sold me everything he had a year ago.

Any help would be appreciated.

 

[bulgie]

Might be similar enough to a Precision Matthews PM-935TV, check out their docs maybe?
Note they also sell the PM-935TS, which would not have the same head as yours.

Can't tell by eye but I assume this is a bit smaller than a full-sized Bridgeport, amirite? That is a dream mill for me, all the functions of a BP but in a size I could almost handle in my shop. Alas I think I'm stuck with a benchtop for the foreseeable future. I used a knee mill at work before I retired and so I am spoiled, but I have to admit my benchtop does everything I need it to so far.

Is the head on yours a lighter color paint than the base, or is that just light/shadow? You do hear of mix'n'match milling machine parts sometimes, even between different brands. Lots of imports are so faithful a BP knock-off that their parts are interchangeable with BP or other knock-offs.

 

[matthewsx]

Have you looked at H & W Machine's website?

Home

Your trusted source for Bridgeport Machine Replacement Parts and Services. We're the best place to get metalworking parts & services online!

machinerypartsdepot.com

They have a ton of info on Bridgeport and clones online, and people you can talk with if you have questions.

John

 

[PNW_Guy]

Might be similar enough to a Precision Matthews PM-935TV, check out their docs maybe?
Note they also sell the PM-935TS, which would not have the same head as yours.

Can't tell by eye but I assume this is a bit smaller than a full-sized Bridgeport, amirite? That is a dream mill for me, all the functions of a BP but in a size I could almost handle in my shop. Alas I think I'm stuck with a benchtop for the foreseeable future. I used a knee mill at work before I retired and so I am spoiled, but I have to admit my benchtop does everything I need it to so far.

Is the head on yours a lighter color paint than the base, or is that just light/shadow? You do hear of mix'n'match milling machine parts sometimes, even between different brands. Lots of imports are so faithful a BP knock-off that their parts are interchangeable with BP or other knock-offs.

I know it's a copy of a J head Bridgeport, which is what everybody else copied. I'm just not sure if the belt is the same size and all that.

It's a bit larger than the average Bridgeport. 9x50 table. The drawbar is at least 7' up. It's the perfect size for what I do, and the space I have.

As far as I can tell, it's all original. Everything matches - color and sheen of the paint, and even the amount of grime.

I think I got really lucky with this machine, being pretty lightly used for most of its life. The PO made a lot of engine models, and mostly did small work in soft materials. For example, I got all of his tapping tools - there was a Tap-Matic tapping head that went up to #10 or #12. He had matched sets of tap bits, clearance bits, counterbore bits and all three tap styles - from 0 to #12. My assumption is that it saw high RPM but no load.

 

[PNW_Guy]

Have you looked at H & W Machine's website?

Home

Your trusted source for Bridgeport Machine Replacement Parts and Services. We're the best place to get metalworking parts & services online!

machinerypartsdepot.com

They have a ton of info on Bridgeport and clones online, and people you can talk with if you have questions.

John

Good call. They are probably my best option.

 

[FOMOGO]

I have a similar machine. It's 10x54, 3hp, with square ways on the Y. Pretty much the same as the BP, and the other clones. IIRC it runs 3400lbs. Did a complete tear down on it. Repaired a few things, and replaced the nut on the Y axis. Still need to get a DRO installed. Think it's going to be a keeper, but still hanging onto the Bridgeport. Yours seems to be in really nice shape. Mike