[arvidj]

Pete,

About what page in "Finally Getting Started ..." do you talk about the belt drive conversion? Even a date range would help. Yes, I'm trying to avoid looking thru the entire 65 page thread.

Ok, I'll answer my own question. It looks like post #78 is where Pete first mentions it and #85 is the first mention of real work being done.

Thanks,
Arvid

[pete from TN]

Hey man I honestly would have to look at it as well. I did most of the documentation on the belt drive in another thread I made called RF45 Lathemaster belt drive conversion I hope or something like that.... It shows some pictures of what I did and how I did it. From what I gather the basics could be done on the IH machine altho the coupler I used apparently will not fit the IH spindle body. I am sure you could do something similar with the IH and another option is to take the drive gear that couples the spindle to the gear train and order another one and machine it to accept the bearings and whatnot. It really is not a difficult thing to do and once you tear into it things become clearer. Good luck and PEACE!!

Pete

[yooooda]

As others have already posted, the 1920 is the highest spindle speed with the stock arrangement. That said MTW says they put VFDs on these mills regularly with no problem. Interesting side note. The actual IH mill has a stock top end of 1500 something rpm. They said when they put a VFD on theirs they typically get around 3400 rpm. The MTW uses the same type of hardened gear sets in the head. They just had to have different speeds to be 'different'. That said, if the MTW top end is some 400 rpm higher than the IH, then putting the VFD on should get you close to 3800 rpm at the top end.
Has anyone actually done this and checked?

[SCzEngrgGroup]

As others have already posted, the 1920 is the highest spindle speed with the stock arrangement. That said MTW says they put VFDs on these mills regularly with no problem. Interesting side note. The actual IH mill has a stock top end of 1500 something rpm. They said when they put a VFD on theirs they typically get around 3400 rpm. The MTW uses the same type of hardened gear sets in the head. They just had to have different speeds to be 'different'. That said, if the MTW top end is some 400 rpm higher than the IH, then putting the VFD on should get you close to 3800 rpm at the top end.
Has anyone actually done this and checked?

If you buy an IH mill with VFD, it comes with a different motor. The stock motor is a single phase, while a VFD requires a three-phase motor. Most any three-phase motor can be run to at least twice its base speed.

Regards,
Ray L.

[pobanion]

Hi Guys...

The stock 3 phase motor for the MD001 machine can be run with a VFD up to 4000 rpm safely according to the engineers at the factory. However according to the engineers, the stock spindle bearings on the machine are only suppose to be rated for 3000rpm. I suppose you could over run them a little but that would be up to you.

The top gear ratio is 1920/1750 = 1.097. That gives a potential rated top motor speed of 2735 rpm to get 3000 rpm on the spindle. While it is true these motors are not "inverter duty", I have been running one in my basement for a couple years not without any trouble. I have also sold quite a few without any complaints.

Regards,
Pat