that is 
My Goddard-inspired "Big-Red"-like grinder is probably all I will ever need,
small FP, plenty of power (can not stall 11" contact wheel with 3/8 D2), dirt-cheap (HF's $69 Buffer-grinder + some angle iron), multi-functional (full time buffer wheel on other end, platen and contact wheel can changed in 60 secs), nice tracking ....
But then again, the Holidays are coming and one has to reward himself with a new tool
.
I am thinking about building Bader-like grinder, direct drive off 2HP 3Phase VFD-controlled motor.
The idea is to junk-yard score 1/2 thick steel plate, 12x12 or so, face-mount the motor to the lower portion, in the upper area: fashion a horizontal square channel - for the tool arm, and upright 1.5 square for the tracking wheel's vertical pivot point and be done with it.
Bottom line (we are in big league now, $69 doesn't cut it
anymore ) :
- nice inverter-rated 2HP 3Phase TEFC motor: $200 (buy locally, shipping charge will kill ya). Must have base AND face mount. Or, try to save $60 buying from Ebay .. not worth it .
- NEMA-4 VFD: $350 (low-weight, low shipping). For $250 you can get Hitachi L200 in NEMA-1, but it will burn out in a year (???) as metal dust builds up inside. There doesn't appear a way to save on VFDs. Good ones command premium ... EOSP !
- figure another $100 for 3 feet of 2x2 square HRS, for tooling arm, some additional steel here and there
- I have a nice collection of surpluscenter rollers and flat pulleys I modified to contact wheels.
Plus, with me mill, lathe, MIG & TIG, 4x6 BS there is no limit to what I can make in the way of tooling for it.
Bottom line: $700 for a workhorse of a grinder. Now, with all the fun in the process of making it (priceless !), it will be virtually free at the end
Now, were I a fulltime knifemaker, I'd most certainly buy one ready-made - KMG or Bader, building one wouldn't be worth the time/effort and lost opportunity cost would just kill ya (spending 2-3 weeks building the tool-of-the-trade as opposed to the product you sell).
Now the questions I have:
- will 1/2 12x12 plate be rigid enough to serve as foundation for the grinder ?
- will motor's base mount be strong enough to support the whole thing ? I figure it would be smart to have the 12x12 vertical plate securely anchored to the workbench, in addition to securing the base of the motor
- Motor being easily reversible, I will go for ambidextrous setup, where belt can be on either side of the motor, for those who'd dare to repeat me design.
In my case, space being a constraint, I need the belt to be on the LHS of the motor.
In the way of add-ons, I am thinking about making a buffing wheel attachment and a disk grinder one. I am fine with them being driven
by 2x72 regular belts. Or may be I will groove the driving wheel for a V-belt
(will having a 3/8" wide grove in the driving wheel be detrimental to the abrasive belts ? )
My Goddard-inspired "Big-Red"-like grinder is probably all I will ever need,
small FP, plenty of power (can not stall 11" contact wheel with 3/8 D2), dirt-cheap (HF's $69 Buffer-grinder + some angle iron), multi-functional (full time buffer wheel on other end, platen and contact wheel can changed in 60 secs), nice tracking ....
But then again, the Holidays are coming and one has to reward himself with a new tool
.I am thinking about building Bader-like grinder, direct drive off 2HP 3Phase VFD-controlled motor.
The idea is to junk-yard score 1/2 thick steel plate, 12x12 or so, face-mount the motor to the lower portion, in the upper area: fashion a horizontal square channel - for the tool arm, and upright 1.5 square for the tracking wheel's vertical pivot point and be done with it.
Bottom line (we are in big league now, $69 doesn't cut it
anymore ) :- nice inverter-rated 2HP 3Phase TEFC motor: $200 (buy locally, shipping charge will kill ya). Must have base AND face mount. Or, try to save $60 buying from Ebay .. not worth it .
- NEMA-4 VFD: $350 (low-weight, low shipping). For $250 you can get Hitachi L200 in NEMA-1, but it will burn out in a year (???) as metal dust builds up inside. There doesn't appear a way to save on VFDs. Good ones command premium ... EOSP !
- figure another $100 for 3 feet of 2x2 square HRS, for tooling arm, some additional steel here and there
- I have a nice collection of surpluscenter rollers and flat pulleys I modified to contact wheels.
Plus, with me mill, lathe, MIG & TIG, 4x6 BS there is no limit to what I can make in the way of tooling for it.
Bottom line: $700 for a workhorse of a grinder. Now, with all the fun in the process of making it (priceless !), it will be virtually free at the end
Now, were I a fulltime knifemaker, I'd most certainly buy one ready-made - KMG or Bader, building one wouldn't be worth the time/effort and lost opportunity cost would just kill ya (spending 2-3 weeks building the tool-of-the-trade as opposed to the product you sell).
Now the questions I have:
- will 1/2 12x12 plate be rigid enough to serve as foundation for the grinder ?
- will motor's base mount be strong enough to support the whole thing ? I figure it would be smart to have the 12x12 vertical plate securely anchored to the workbench, in addition to securing the base of the motor
- Motor being easily reversible, I will go for ambidextrous setup, where belt can be on either side of the motor, for those who'd dare to repeat me design.
In my case, space being a constraint, I need the belt to be on the LHS of the motor.
In the way of add-ons, I am thinking about making a buffing wheel attachment and a disk grinder one. I am fine with them being driven
by 2x72 regular belts. Or may be I will groove the driving wheel for a V-belt
(will having a 3/8" wide grove in the driving wheel be detrimental to the abrasive belts ? )
