RF-31 or RF-30 Power feed

[Cmdevans]

Has anyone adapted a Bridgeport/knee mill style power feed to their RF-30 or RF-31 mill? All of the power feeds I see for these look like they have some flaws I'd like to avoid putting on my mill. Plus, they are typically 2-3 times more expensive for some reason, even though they use the same motors as the other power feed/drive units.

Basically, I want to put one of these:

Mophorn Power Feed Al-310S X-Axis Torque 450 in-lb Power Feed Milling Machine 200PRM Power Table Feed Mill Fits Bridgeport Acer (450 in-lb X-Axis Torque) - - Amazon.com

Mophorn Power Feed Al-310S X-Axis Torque 450 in-lb Power Feed Milling Machine 200PRM Power Table Feed Mill Fits Bridgeport Acer (450 in-lb X-Axis Torque) - - Amazon.com

www.amazon.com

On this:

8" x 29" 2 HP Mill/Drill with Stand - Grizzly Industrial

<h1>G0705 8" x 29" 2 HP Mill/Drill with Stand</h1> <h2>A competitively priced mill worthy of being the cornerstone of your shop.</h2> <p>The G0705 8" x 29" 2 HP Mill/Drill has a 2 HP motor and enough table space to make quick work of just about any machining job you can throw at it.</p> <p>The...

www.grizzly.com

 

[jwmay]

Grizzly sells a unit for that machine. I don’t remember it costing 175 dollars times 2.

I think a problem you may run into with that unit is that it will run into the cabinet at either end of your travel. It hangs down, you see. The unit that’s sold for that machine is horizontally mounted. So it will never run into the cabinet. Then again, I could be wrong. Who am I to dash your dreams? But if it WERE me, I’d just buy the direct bolt in unit. There will be plenty of engineering problems to solve, even if you pass this one by, and just bolt on the right unit.

 

[jwmay]

Power Feed for Mill / Drills ALSGS - Grizzly Industrial

<h1>H8370 Power Feed for Mill / Drills </h1> <h2>If you want to get the most out of your mill drill, you really need a power feed.</h2> <p>The H8370 power feed is designed to install on the left side of a mill/drill table to provide powered longitudinal movement of the table.</p> <p>The...

www.grizzly.com

I stand corrected...

 

[darkzero]

All of the power feeds I see for these look like they have some flaws I'd like to avoid putting on my mill.

What flaws were you concerned about? I have the ALGS AL-310S that are made to bolt on mill/drills on my RF-45 style mill. I've never had a problem with it.

 

[Cmdevans]

@jwmay: I couldn't find one on the Grizzly site either. Cheapest I have found is around $300 with shipping for a Shars Unit on ebay, but the other two I found are about $400-500. (OK, so I just found one that MSC has as well for a bit over $300)

I know it sticks down. I'd either lose 3.5" of travel in that direction or I could just make a shaft and block that extend the screw and bolting area out that same distance.


@darkzero: I think that helps. It sounds like you have the same power feed unit that I linked to. I believe that the RF-30 and RF-45 share the same basic table and lead screws, though I could be wrong. I am guessing you lose a little travel on one side?

This is the style that is technically made for the RF-30-31:

560 Inch Max Peak Torque Per Pound, Table 41046715 - MSC

Discover Value Collection Milling Machine Power Feeds at MSC Industrial Supply. Over 1 million products that ship and deliver fast

www.mscdirect.com

Two main flaws.

First, the casting that clamps to the table seems to be weak and subject to breaking (mostly due to people over tightening them) . Id like to have one that bolts on rather than clamps on to completely bypass that issue. If its a common failure point with over tighting, I'd imagine that is likely not going to stand up over time to the sorts of pressure that I will likely have on it. I often have large 8' pieces of wood clamped to the table, and as soon as you let off the clamps there is a lot of pressure put right where that cast clamp goes. Which brings me to the other point.

Second, since I clamp flat to the table and have the ends of a lot of stock overhanging each end, any raised surface at the end would be an issue for me. On the style that is made for my my RF-30 clone the forward/reverse lever, the end of the motor and the clamp all go 1/2" or so above the table surface.

 

[jwmay]

I should have been more clear. Above, I linked to the power feed unit that is sold by Grizzly, and fits your mill. But it’s over 175 dollars times 2. That won’t work though, due to the reasons you just typed. Wish I could have been more help.

 

[mikey]

I have an Align power feed and you're right, it sits above the level of the table. BUT the key thing is that it is a direct mount that bolts up to the table using the two bolts this mill uses. The Mophorn unit has 4 holes and I don't think it will fit.

 

[darkzero]

@darkzero: I think that helps. It sounds like you have the same power feed unit that I linked to. I believe that the RF-30 and RF-45 share the same basic table and lead screws, though I could be wrong. I am guessing you lose a little travel on one side?

This is the style that is technically made for the RF-30-31:

560 Inch Max Peak Torque Per Pound, Table 41046715 - MSC

Discover Value Collection Milling Machine Power Feeds at MSC Industrial Supply. Over 1 million products that ship and deliver fast

www.mscdirect.com

Two main flaws.

First, the casting that clamps to the table seems to be weak and subject to breaking (mostly due to people over tightening them) . Id like to have one that bolts on rather than clamps on to completely bypass that issue. If its a common failure point with over tighting, I'd imagine that is likely not going to stand up over time to the sorts of pressure that I will likely have on it. I often have large 8' pieces of wood clamped to the table, and as soon as you let off the clamps there is a lot of pressure put right where that cast clamp goes. Which brings me to the other point.

Second, since I clamp flat to the table and have the ends of a lot of stock overhanging each end, any raised surface at the end would be an issue for me. On the style that is made for my my RF-30 clone the forward/reverse lever, the end of the motor and the clamp all go 1/2" or so above the table surface.

The one I have is the one that mounts horizontally & is the same one for the RF-30/31. The drive unit is the same as the one you first linked except it's setup for horizontal use, rapid switch is remote mounted on the bracket. Mill/drills don't have the room for the power feed to be mounted verically like on knee mills. As mentioned you'd loose travel on one side. Mounted horizontally I have no loss in travel except for the room needed for the limit switch & stops.

I've never heard of anyone cracking their mount from overtightening but I wouldn't be surprised as there's always a "200lb gorilla" out there. The clamping "system" are just 2 cone point bolts (I think, I forget, been a long time since I installed it). I've never had an issue with mine but I never lean on mine or put heavy parts on it.

You could possibly make a simple L bracket to bolt to the existing holes for the cone point bolts then drill/tap a couple of holes straight down in the table end cavity. Still this would not address the issue you have of clamping long work pieces. Whenever I clamp a long work piece, which is not often, I'll use 123 blocks or material to raise the piece off the table to clear the power feed. Not really intentionally to clear the power feed but usually cause I need to drill holes so I need to raise the work piece up off the table.

If you need to clamp long pieces directly to the table sounds like the only way around this is to make your own bracket & drive gear. But in that case it would probably be better to build your own power feed from scratch rather than modifying one of these units. Lots of great examples of power feeds built from scratch out there to get ideas from.

 

[darkzero]

BUT the key thing is that it is a direct mount that bolts up to the table using the two bolts this mill uses

What?! Interesting, yours actually bolts onto the table? I thought all these power feeds for mill/drills used the same basic design. I'm jealous, wish mine bolted directly to existing holes on the table but whatever, mine is secure, it's never gave me trouble.

 

[mikey]

What?! Interesting, yours actually bolts onto the table? I thought all these power feeds for mill/drills used the same basic design. I'm jealous, wish mine bolted directly to existing holes on the table but whatever, mine is secure, it's never gave me trouble.

I embarrassingly stand corrected. The power feed unit bolts to an L-shaped bracket that fastens to the end of the table with two bolts. This positions the drive gear over the driven gear on the leadscrew. There is also another L-bracket that bolts to the first L-bracket and also to the inside of the table edge. It is solid enough.

I do not see how you can adapt a four-hole attachment to the end of a RF mill, though. I don't think it will fit but then again, I haven't actually seen one done so maybe its possible.