Needs Pictures: 0
Results 1 to 15 of 15
Thread: Belt sander issue
-
10th Apr 2020, 01:55 AM #1Golden Member
- Join Date
- Dec 2007
- Location
- Adelaide
- Posts
- 575
Belt sander issue
A while back I picked up one of these belt/disk sanders (Gumtree) to replace the old hand held belt sander that I used to turn upside down and sit it on the bench, I ordered a selection pak of belts from Ebay with various grits, and set it up with the belt in the vertical position and up until now I have only used it for wood, plastic and fibreglass sheet with no issues. I had need to shape some brass and have noticed that there is marked thump as the join on the belt passes the brass being shaped, I have never noticed this from the old hand held belt sander - is this normal or have I just got a cheap set of belts with poor lumpy joins ?
-
10th Apr 2020, 02:39 AM #2
Hi Familyguy,
I've got one of those. Mine thumps as well even putting the belt on facing the right way makes no difference. DAMHIKT. I find that it stalls very easily. I replaced the capacitor thinking that it was bad, but it made no difference. Just not enough motor power from 250 Watts for anything but wood. Biggest improvement was a new smaller section belt. I've been meaning to put a treadmill motor on mine for ages, but not got round to doing it !Best Regards:
Baron J.
-
10th Apr 2020, 09:27 AM #3Member: Blue and white apron brigade
- Join Date
- Feb 2006
- Location
- Perth
- Posts
- 7,189
-
10th Apr 2020, 09:58 AM #4
I had 2 of them, as said not enough power and mine always thumped like yours.
Ended up selling both years ago and bought the biggest 240v model from H&F.Using Tapatalk
-
10th Apr 2020, 10:39 AM #5
They all thump, I've messed around with mine trying to get rid of it. It does improve with higher quality belts but never disappears completely.
I found by adding a stick on slip pad thingo helped a lot(cant remember what its called... its pretty slick stuff graphite impregnated I think)under the belt on the plattern/work area, I got it from Timbecon years ago but they dont seem to list it anymore?....................................................................
-
10th Apr 2020, 10:43 AM #6
Ah ha found some at Carbatec search for "GRAPHITE-150MM"
....................................................................
-
10th Apr 2020, 11:29 AM #7Senior Member
- Join Date
- Nov 2019
- Location
- Brisbane
- Age
- 69
- Posts
- 452
Belt grinder
Hello again.
These cheap belt grinders are not good for metal removal. The small diameter drive wheel means the surface speed of the belt suits wood, but metal use leads to a poor finish and grain shedding. Still if you can't afford the right thing.
Belts with tape joins will always thump as the thickness at the join increases. Well made lap joins with the abrasive skived off the top on one side and the backing ground to remove fillers and prepare the cloth or combination material should run well. Once again pay for good quality product.
The graphite impregnated canvas used on the platten is called slip cloth and will help if it doesn't raise the plate above the belt tracking height.
My small belt grinder has a Norton Blaze belt I received as a sample maybe 5 years ago. The top size coating is mostly gone but the grain keeps going. I keep well away from it when starting up in case the join fails.
In my opinion the Multitool linisher attachment can't be beaten for value and working life for small industry.
regards
BC
-
10th Apr 2020, 05:38 PM #8China
- Join Date
- Dec 2005
- Location
- South Australia
- Posts
- 1,658
Are the belts overlapped or butt jointed.
-
11th Apr 2020, 02:16 AM #9Golden Member
- Join Date
- Dec 2007
- Location
- Adelaide
- Posts
- 575
The belts are overlapped, probably not the best idea to get the cheapest, more expensive brand name belts probably have better made joints.
I haven't noticed any lack of power with the stuff I've been sanding so far, some the comments made in this thread mention that these things are under powered so I tried to grind a radius on a mild steel bar around 30mm wide 8mm thick - pressing as hard as I dare due to the thump/knock from the join in the belt and it did not appear slow it down, radius was ground with no issues, it's hard to read but it looks as if the motor is labeled 0.18Kw or 180 watts and 2.5 amps - doesn't say much for the efficiency of the motor, I always thought small induction motors were around 55% - 60% efficient, with Chinese motors who knows, they seem to have their own standards.
-
11th Apr 2020, 04:04 AM #10
Hi Familyguy, Guys,
Mine definitely says 250W, but it couldn't pull the skin off a rice pudding !
I've actually got a spare motor for this machine that originally came off the original one that I had. That one had a seized up roller. I managed to break the plastic trying to get it apart.
Both my machines came from the scrapyard as rescued ones.Best Regards:
Baron J.
-
11th Apr 2020, 05:43 PM #11China
- Join Date
- Dec 2005
- Location
- South Australia
- Posts
- 1,658
Many people replace the motors on these with more powerful units, plus using butt jointed belts will all but eliminate the bump
-
11th Apr 2020, 10:00 PM #12Most Valued Member
- Join Date
- Jul 2006
- Location
- Athelstone, SA 5076
- Posts
- 4,258
I am at a loss to comprehend how a under powered belt grinder can be the cause of the thump i experience with a 3 mm radius on 4mm flat bar with a 2 x 72inch belt grinder driven by 3hp motor.
-
11th Apr 2020, 10:03 PM #13Gear expert in training
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 1,080
I don't know if they still do, but the large Norton Metallite belts we used on the linisher at my old work had a squiggly butt join with tape on the back for strength; very smooth running.
-
12th Apr 2020, 12:00 AM #14China
- Join Date
- Dec 2005
- Location
- South Australia
- Posts
- 1,658
The bump is caused by the cheap over lapped joints on the belt
-
12th Apr 2020, 12:14 AM #15Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,959
It's not only cheap belt that have the overlaps. Good quality belts have tape over the butt angled joint, they are harder to find.
KrynTo grow old is mandatory, growing up is optional.
Similar Threads
-
Looking for old belt sander - see link
By jhovel in forum METALWORK GENERALReplies: 7Last Post: 5th Jul 2016, 07:57 AM -
Hafco BS-48 Belt linisher/ sander
By dradyz in forum METALWORK - Machinery, Equipment, MARKETReplies: 0Last Post: 23rd May 2016, 06:51 PM -
Disc and belt sander
By Maxi77 in forum METALWORK GENERALReplies: 32Last Post: 26th Jun 2015, 10:17 AM -
My new belt sander
By Stustoys in forum METALWORK GENERALReplies: 8Last Post: 24th Mar 2011, 09:40 AM -
using belt sander as linisher
By Com_VC in forum METALWORK GENERALReplies: 3Last Post: 25th Nov 2007, 02:42 PM