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Grob 4v-18 Questions (Guides and Tires)


Feb 20, 2014
Hello all,

I just picked up a 1980 Grob 4V-18 via auction. I was unable to inspect it so took the gamble. Was able to start it up for a few seconds when I picked it up to confirm the thing ran at least.


The good:
  • Seems to be in decent overall shape
  • Opened the back cabinet and found both the rip fence (thought it was missing) and a circle cutter attachment
  • Turns on at least
  • 7.5 KVa transformer attached that I don't need and can use elsewhere (machine currently wired 460V)

The bad:
  • The upper guide is some sort of homemade ball bearing setup (machining not up to a commercial piece)
  • Lower guides missing, holder worn badly (luckily, newer holder in cabinet)
  • Some random color repaint (paint job in the future to factory green)
  • Rip fence guide in the front is bent, I'll need to straighten it or make a new one.


The ugly:
  • Lower tire missing altogether, wheel has some damage on it.


So, I have three questions:
1) Is the lower wheel salvagable with a new tire? It feels like the majority of the crown is still there, and I'm home a new tire will at least get it to servicable condition. This is for my personal shop, so won't be run 8 hrs a day, so I'd prefer not to spend $500 for a new wheel if I can avoid it. Plan is to use the factory rubber tires unless someone makes a case for urethane being the greatest thing ever.

2) As I'm missing the upper guide holder, I can either buy a new factory one and a new set of guides, or for almost the same money get a set of Carter roller guides. Does anyone have experience with these on a Grob saw?


3) Can someone confirm this is the correct lower guide holder? It looks to match the images Grob has as best I can tell.


Hopefully in the next few days I'll be able to rewire it to 230V and clean it up, change out the gearbox oil and make sure all else is good.

What car2 said...I have an NS-18 too, but with Carter roller guides on it.

My guides were incomplete, so going with new, easily available seemed like a good idea at the time, though I wouldn't do it again. At 2050 max sfpm, they're just not needed and chips that have escaped the (added) chip brush are more likely to roll between the bearings and the blade. Solid guides give more support to the blades at those speeds and last I checked, they're still available from Grob.

The roller guide you've shown is not that much different than the Carter guides. So long as the rollers have adjustments for blade thickness and position, you're all set. The Carter guides have bearing mounting holes tapped offcenter so the shafts are rotated for alignment. The holes in the Carter bodies are too large for the shafts (IMO) so adjusting them is an exercise in fiddling around. Maybe there've been changes, but at the time there was no provision for blades wider than 1/2". I think the 4V will accomodate 1" blades.

The 4V18 runs quite a bit faster than the NS18, so if you cut a lot of wood, roller guides might be useful. Carter is making their kits to a price point, ruggedness reflects that. They work well for light to medium duty work, with fiddling, but they're nowhere near the quality and construction of Black Diamond guides, for example.

Grob also sells tires for their saws and upper blade guards, too. (Looks like that saw needs one.) They were very helpful and had parts in stock when I needed them for my saw - I'd use them again in a heartbeat.

Good luck, keep us posted.
Thank you both for the replies so far, definitely helpful to hear your experiences on the guide. This will be my only (planned) vertical bandsaw, so it'll cover a mix of steel, aluminum, and wood. Maybe some stainless in there but likely nothing exotic. My plan is to primarily run 1 inch blades, at least for metals, and then maybe 1/2 blades for curved cuts or wood.

I have two of the lower guide holders, although one is toast by means of being run without the bronze guide for too long. The upper bearing one is also pretty far gone. The side support bearings are too narrow to do a good job with a 1 inch blades, and they're only about 1/2 inch in diameter, so spinning way too fast at the upper end. The saw will do 5000 from and I figure I'll run it in the 3000 - 5000 fpm range a fair amount for aluminum and wood.

The lower I have seem to be for the smaller size guide blocks, going up to 1/2. If anyone has any good images of the larger holder (both bottom and top) that use two screws instead of one, it'd be greatly appreciated, as these seem like very simple parts to make and would set me back over $300 from Grob, before the guide blocks. I'm trying to define if the larger holders use the screws to press directly on the guide blocks, or clamp like the smaller one with a single screw. I'm basing all this off the images Grob has for these holders (single isometric CAD images).

I think my plan at this point is to make upper and lower holders for the Grob 1 inch guides for now. After that, I'll either make a Carter style guide (figure I can probably make something for $40 with cheap bearings to start, and would handle wood better), or make the upper small guide holder to use the Grob guide for 1/2 blades as well. Maybe someday I'll make a set of Black Diamond or Doall clone guides.

I'll be ordering some tires in the short term. Now leaning towards either urethane tires from Sawblade or Sulfur Grove.

Thanks again.
FWIW, my tires came from Grob. They were reasonably priced and much more even thickness than the other two sources' tires, who shall go unnamed.

They needed no shaping after installation and have run for 22 years, used almost daily.
Here's a few pics of the setup on my 4V-18. I like to run a 1" blade on mine too. A one incher will cut into your table cover plate a little, and also your shields and doors, but just a little. That or you really have to get the distance towards or away from you just right. Maybe if I had the factory bronze guides for 7/8-1" it wouldn't do this. I use the Carter roller guides pictured when running one inch.

You won't get much form cutting done even with 1/2". 1/4" is good for that.

If you don't have the manuals for the machine check with Grob.I bet they still have them and they are super handy for service and parts. You wouldn't need any of these pictures if you had the books, as the books are even better then the pics.

BTW - Been running mine without a lower tire like forever. Still going. Though I will admit my rim looks better then yours.

The one pic is of the factory contour attachment (never used) and the power feed bar I made.


Forgot one you might need.Grob_4.jpg