[Bird_E]

Does anyone know if the rf45 clone Square column mill can be converted to a belt drive setup?

I would think, for milling alum and such that more spindle speed would be nice, and with all those gears in head for power and speed changes this will limit how fast you can turn the spindle. I would imagine a 2 HP vfd belt drive to the spindle would allow much higher spindle speeds. I have mill on order, so I haven't seen the insides yet. But does anyone know if this is possible with minimal work?
Thanks!
Bob

[NC Cams]

You really need to figure out the loads you'll be running and the speeds you'll be running at and do the load calcs with the belt sizes you plan to run.

Once you know this and run the numbers via the power tranamission formulae, you'll be able to determine the viability of the project.

Most industrial belt drive catalogs and/or handbooks provide the formulae and shock load assumptions needed to determine belt sizes and projected belt life.

2hp at 1750 rpm has a much different torque factor than a 2hp motor at 3500 rpm and TORQUE is what is going to create the forces that you'll have to deal with.

HP= torque x rpm/5252 and torgue is expressed in ft-lb

Multipy torue by shock factor to provide for the inevitable oops and/or a factor of safety.

[ChrisJ]

It is my understanding that Aaron at IH had successfully converted one of his mills to belt drive. I believe he changed the spindle out to a #30 at the same time.

Chris

[Brian Kidd]

It is my understanding that Aaron at IH had successfully converted one of his mills to belt drive. I believe he changed the spindle out to a #30 at the same time.

Chris

Yeah at one time when I was talking to him he did do this and he was thinking about setting it up as an option for the conversion.

B.Kidd

[IndHobby]

Yes, you can convert it to belt drive. It does take some machining, a few custom made components, and some minor head adjustments, but it does work and it does go fast.

We will be offering it as a listed modification in a couple months along with prices. It's not something we're going to give away simply because it took some time to figure our.

We will probally sell it in a few ways:

Instructions and plans.
Instructrions/plans and major pieces machined.
We do everything.

Of course the farther down the list you go the more it costs, but I'm guessing prices will be pretty reasonable.

[Bird_E]

If I may ask a couple of more questions:
When converted to belt drive, what kind of spindle speeds are we talking about? Also, do you feel any capability of the machine is lost when converted to a belt drive?

And I completely understand your need to post only "General" information.
Thanks again!
Bob

[phil burman]

Seems kinda strange to buy an RF45 (read geared head mill) then convert it to beltdrive, bypassing the gear box. That's a significant portion of the total cost of the machine sitting there redundant. Or have I missed something.


Regards (chair)
Phil

[Bird_E]

To me the biggesst asset of the machine is it's mass and rigidity for a desktop Mill. However, if you want to use small cutters and get good finishes on aluminium A higher speed spindle would be nice, the gear box doesn't lend it's self to running at high speed. For that reason I believe belt drive would give you more opportunity for higher speeds.
Bob

[phil burman]

Exactly Bob.

If you want or need much above 2,000 rpm then a geared head is not going to make it. Look at a high end BP type, 60 to 4,000 + rpm. They have VFD with belts to change ranges. But then a BP doesn’t have a column in the way to restrict the design of the pulley system. You can easily get high-end speed with a compact pulley arrangement but for low speed pulleys need diameter in order to handle the additional torque, assuming you want to use all the available horsepower. Square column mills don’t have the space. That’s why there are no square column belt drives out there, at least not without a variable speed motor. The next significant step in the evolution of the square column bed mill is going to be a drive system that gives both high and low speed capability. This might be a hybrid using a VFD with pulley drive for high end speed and gear drive for low speed torque.

Regards
Phil

To me the biggesst asset of the machine is it's mass and rigidity for a desktop Mill. However, if you want to use small cutters and get good finishes on aluminium A higher speed spindle would be nice, the gear box doesn't lend it's self to running at high speed. For that reason I believe belt drive would give you more opportunity for higher speeds.
Bob

[TPPJR]

Exactly Bob.

If you want or need much above 2,000 rpm then a geared head is not going to make it. Look at a high end BP type, 60 to 4,000 + rpm. They have VFD with belts to change ranges. But then a BP doesn’t have a column in the way to restrict the design of the pulley system. You can easily get high-end speed with a compact pulley arrangement but for low speed pulleys need diameter in order to handle the additional torque, assuming you want to use all the available horsepower. Square column mills don’t have the space. That’s why there are no square column belt drives out there, at least not without a variable speed motor. The next significant step in the evolution of the square column bed mill is going to be a drive system that gives both high and low speed capability. This might be a hybrid using a VFD with pulley drive for high end speed and gear drive for low speed torque.

Regards
Phil

True 2 speed RF-45's do 3k out of the box. But the gear box is noisy for me and I am fighting high running temps when running full speed for over an hour. I got the mill for the square column not the gear box. I wish it was belt drive and my look into converting it in the future.

Thomas

[phil burman]

Hi Thomas,

What 2 speed RF-45 are you referring to

Best Regards (chair)
Phil

True 2 speed RF-45's do 3k out of the box.

Thomas

[TPPJR]

Hi Thomas,

What 2 speed RF-45 are you referring to

Best Regards (chair)
Phil

Phil,

As far as I know Roung-Fu only makes one two speed RF-45 gear head.

Thomas

[phil burman]

You mention 3,000 rpm. The only two sped RF45 I can find is 2,500 rpm. I can't find any 2 speed RF45's on the RF website!!!

Just curious if the 2 speed is a dealer mod or original from the factory.

Phil

Phil,

As far as I know Roung-Fu only makes one two speed RF-45 gear head.

Thomas

[TPPJR]

You mention 3,000 rpm. The only two sped RF45 I can find is 2,500 rpm. I can't find any 2 speed RF45's on the RF website!!!

Just curious if the 2 speed is a dealer mod or original from the factory.

Phil

Original from the factory. I got it from a local shop in Hawaii.

Thomas

[Mortgaged]

I can really understand wanting to go to belt drive just from the noise aspect alone. My machine is loud enough with the OE motor that it already wakes up my wife and kids from my basement shop. I can't imagine what it would sound like with the 3450rpm motor! Some gear combinations are worse than others, it's mostly the 3rd position in either low or high that is at least 3x louder than any other gear. Is this common for the geared head and will it quiet down after the hardened gears wear-in?

I'm really not pleased with the whole gear head/quill arrangement as my machine has a particularly sloppy quill that easily moves >.015" during it's travel. Tramming is almost irrelevant and I have to keep the quill retracted and use the hand crank when I really need to maintain accuracy (flatness).

I would love to convert the whole head assembly to a Cat 30 spindle belt driven by a servo motor thru a VFD (kind of like a HAAS). Skip the quill and counterbalance the head for easy up/down movement. Maybe relocate the hand crank? It would only help for the eventual conversion to CNC. It may take me a couple years, but I will come up with something as the current amount of slop is not tolerable.

[MikeAber]

[QUOTE=Mortgaged]
I'm really not pleased with the whole gear head/quill arrangement as my machine has a particularly sloppy quill that easily moves >.015" during it's travel. Tramming is almost irrelevant and I have to keep the quill retracted and use the hand crank when I really need to maintain accuracy (flatness).
QUOTE]

My IH Mill has the same problems with quill travel. Moving the quill down 1" creates more than .020" error in the Y axis. I was trying to drill and bore some holes with less than .001" error perpendicular to the surface and discovered this problem with the quill. Basically the quill is unusable for any precision drilling or boring. Place a DTI in a collet in the quill and measure the run out up and down against a 1-2-3 or 2-4-6 block on the table then get ready to be sick. If you tram the mill head to the table then move the quill to another position the cutting tool is no longer parallel to the table. Don't bother using the quill for your Z axis in a cnc conversion.

If you can find a cartridge spindle with angular contact bearings I would do away with the gear head assembly and replace it with a 2 speed belt driven spindle and a 3 phase vfd controlled motor similar to the PCNC1100 spindle or a DC PWM controlled motor. The bearings in the original gear head will handle 3000 rpm ok; however, there isn't any provision for preload adjustment and a two bearing spindle is marginal in every way. The Gilman spindle Swede has would be perfect on an IH mill. If time is no issue and you or a good friend is a good machinist with a healthy bank account anything is possible.

Mike

[kimoyo]

Has anyone done this conversion?

[DiscretePID]

Aaron (IH Hobby), have you gotten around to make the belt drive conversion packages you intended earlier this year? I am converting my square column to 3ph 2hp motor & VFD and would really like to do the belt drive. Thanks.

[kentavv]

DiscretePID - try giving Aaron a call or write to him at [email protected]

Please let us know what he says. Sounds like a great conversion.

[DiscretePID]

Just spoke with Aaron - very nice guy to speak to. Gives me straight answers and doesn't BS around - my kind of guy. Even though I made it clear I bought my mill from Bob at Lathemaster, Aaron still spend nearly 1/2hour on the phone giving me good and sometimes very poignant advice. I just got into this machining biz recently, and I must say both Bob and Aaron have been great.

Basically, the conversion will be expensive and only worth it for those who need extreme speed for high-rate production runs. Even then, the rest of the mill/CNC/tooling system will have to be upgraded to take full advantage of it.

My application is no where near that demanding. I just need to automate my mill and be able to cut something other than straightline. For now, I will just stay with the gear head. If the gears and/or spindle bearings ever wear out, then it will make more economic sense for me to do the belt drive conversion.