[cncmadness]

I have built the Momus CNC machine and my router died and needs to be replaced. I have been thinking of getting another bosh colt but I have also been looking at the 1.5kv spindle that is available online. I will provide a link. I have a few concerns about the spindle. Will it fit(colt is about 75mm and the spindle is 80mm)? Can the machine carry it(I cand find and spec on the weight of the spindle)? Is there any improvement over the $100 router to justify the extra cost? Is 1.5kv overkill(colt has 1Hp and the spindle has 2HP)? Any insight that can be provided would be a great help. Thanks in advance.

CNC Machine Spindles and Accessories

[DonFrambach]

You don't have do get a 1.5kW spindle. I'm thinking real hard about a much smaller .4kW spindle for my small router. It's air cooled and can be run with a 120 volt VFD. Here's a link: AIR COOLED SPINDLES | CNC SPINDLES | UgraCNC.com

[cncmadness]

That’s a big price difference between the one I found and yours. For the price of the .4Kv SPINDLE i can get the spindle & VFD. I’m sure there is quality difference’s but as for a hobby/small business is it worth the extra money, also the .4Kv is only 1/2Hp which is half the size of the colt. Is that enough power? Also is there any room to advance the machine to do bigger jobs with the .4KV. So at the moment I would still like to compare the 1.5Kv spindle to the colt with the machine I have with possible upgrades in the future. One more question, Air cooled or water cooled. The one I have been considering is water cooled.

[bushwakka]

I would go for the spindle. I killed 4 makita laminate trimmers (around 50hours life cutting 1/4" bit in 3/4" mdf single pass), before moving to a spindle 18months ago. The same spindle is still running, smooth and quiet as ever (around 10hours per week).

Pros
The induction motor in a spindle is much quieter than a brushed series wound motor in a router.
With the adjustable speed, I could reduce the cutter noise and get better chip loading and bit life.
The speed and torque in a spindle is much more consistent around the set frequency.
The speed can be set by the inverter.
You can easily get single phase to 3 phase variable speed drives in the smaller sizes (under 3hp).
It is easy to get collets for the spindles that accept non-standard size bits.
In that size (around 800-1500w) I would probably look at an air cooled unit, as the plumbing/parts for a water cooled unit can be a bit of a pain.

Cons
Cooling, water cooling will require a reservoir, pump, piping and possibly a cooling circuit (Computer radiator or similar). I have no experience with air cooling.
You will need to re-wire out to the z-axis with 3c+e cable (preferably screened cable to reduce the VSD noise).
Different bracket required, and will need mounting to z-axis.

Cheers
Bushwakka

[cncmadness]

Thanks for the great info. I have been cutting UHMW plastic and would like to increase the thickness to about 3/4 to 1 inch thick. What Kv rating would you suggest for best results and the site I had only had water cooled spindles. Does anyone have a good suggestion for a air cooled spindle for a good price. I don't mind spending a few extra dollars but I am still on a budget. Thanks.

[bushwakka]

I've never cut UHMW plastic, only MDF and pine.
I run a 2.2kW water cooled spindle. It normally spins a 1/8" single flute bit single pass in 3/4" mdf at 2.5m/min. It will easily spin a 1/4"bit at this travel speed, but is quiet noisy (cutter noise). I have spun 3/4" bit at 1/2" depth at same speed and it really sounded nice.

The biggest problem with water cooled spindle is getting the water circuit set up.
In hindsight, the easiest option would a a flow control valve from the mains water, and then use the water to water the vegetables.
I have setup a little pressure pump with a pressure tank, then a flow control valve to limit the flow. The pump runs for about 10secs every 5 mins to fill the pressure tank. The return water flows into an 20L oil drum, and the tap fitting at the bottom is fitted with the suction hose for the pump. There is no radiator in the circuit, as I haven't found the need for it.
I used 8mm nylon tube to get the water out and back from the spindle, and it runs in my cable carrier.
The spindles are fitted with a fitting for nylon tube.

My flow rate is about a cup a minute, and I have no overheating issues.

The only other thing I have seen is that the air cooled spindles come in a square frame, and may not require a bracket for mounting. I think the square frame can be/is tapped for mounting.

Bushwakka

[cncmadness]

I was doing some more looking and I found that for a few dollars more the 2.2kv spindle which will take the 1/2 collet were there 1.5kv will only take 1/4" collet. Would it be worth upgrading to the 2.2? and I still have not found out if these options are to heavy for the machine that I am using.

[DonFrambach]

Manufacturers of hand held routers (and shop vacuums) play a little fast and loose with "horsepower" ratings. I note that the Bosch Colt is rated at 5.6 amps at 110 volts while the 1.5 kW spindle is rated at 7 amps at 220 volts. That means that the 1.5kW spindle is almost three times more powerful than the Bosch Colt. You may want to consider a much lighter .8 kW spindle on your small machine (which would still be more powerful that the Bosh Colt.)

I'm thinking of going with a .4 kW for my small router because I take relatively light cuts and the biggest bit I will ever use has a 1/4" shank. For a while, I ran a Taig spindle on my machine which has an ER-16 collet which can accept up to a 3/8" shank. I have an adapter which alllows the Taig spindle to accept 1/2" shanks but I'd never use such a large bit on my small router.

For me, there are two major advantages of these smaller spindles. First, they are air cooled so I don't have to worry about a liquid cooling system. Second, they can be run with a 110 volt VFD which is more convenient for me.

[momus_cnc]

One thing to keep in mind is that the Momus machine is belt drive, which means it can be back-driven. In other words, pull on the belts hard enough, and you can overcome the amount of holding power the stepper motors have. The consequence here is potential runaway climb cutting. This isn't much of an issue with the 1 HP laminate router, unless a CAM programming error moves you too quickly through way too much material. But with a more powerful spindle there is the temptation to start taking more aggressive cuts, and this could get you in trouble. Even without hitting the runaway cutting issue, you could run into machine rigidity limitations or belt stretch problems. The spindle would be a fantastic upgrade, but just be careful not to go crazy with hogging off too much material.

-Bob

[cncmadness]

thanks for the added insight. anyone else have any added suggestions before I start placing orders. As it seems that I am going to go with a spindle and not the colt, is there anyone else that would like to put there two cent in. So far my options are the .8kv spindle, 1kv spindle 1.5kv spindle or the 2.2kv spindle. So far I am liking the .8kv square body as it has mounting holes in it and no brackets will be needed but is there any other benifit to the square body as it is an extra $140 over the round. Also I am still a little concered that the 0.8kv will be less powerful then what I had with the colt.

[DonFrambach]

... Also I am still a little concered that the 0.8kv will be less powerful then what I had with the colt.

I think you'll be pleased to see it is almost 1.5x as powerful as the colt!!

[DonFrambach]

Thank you for getting me going!! I just placed an order for the small spindle I've been eyeing for several months. Hope you figure out what you want and it works well for you.

[electricgraffix]

I have a 2.2kw liquid cooled Chinese spindle. My machine is pretty hefty (J-Cut 1325B). This spindle seems to heat up without a load on it! I am still trying to figure out the cooling system that works well. Anyways, my advise is if your machine isn't hefty, avoid the 2.2, it has some pulling power.

[UgraCNC]

Electricgraffix,

If your spindle heats up unloaded that could mean:
1. Wrong VFD settings.
2. Bad bearings.

If the spindle is new and heats up during test runs then I would recommend you to perform a break-in procedure. The procedure should be performed for every new spindle.

Start your spindle at 10% of the max speed and run for 30-60 minutes unloaded.
It will allow the grease inside of bearings to spread properly. The temperature should raise then drop back to normal.
Then increase speed by 10% at a time and run 30-60 minutes more. Continue till you reach the max speed.

Regards,

Andy

[electricgraffix]

Thanks Andy for the useful advise! Should I break the spindle in without coolant flowing through the motor while it runs unloaded?

[Dylwad]

Thanks Andy for the useful advise! Should I break the spindle in without coolant flowing through the motor while it runs unloaded?

Always have coolant running through it.

Is the heat coming from the cooling jacket, or mainly by the lower bearings?

Sent from tapatalk

[DonFrambach]

Did you get a spindle?

[DonFrambach]

I got the .4kW spindle installed on my small router. It was MUCH easier than I expected. This spindle appears to be about as powerful as the Bosch Colts and a good fit for small routers. Here's a link to my install: http://www.cnczone.com/forums/diy_cn...ml#post1281294