|
Construction Equipment If it digs, pushes, hauls dirt "off road" post it here. |
|
Thread Tools | Display Modes |
#21
|
||||
|
||||
Re: Cat 777D Mining Truck
That's a great looking tire plug you made. Well done! I look forward to seeing the mold and tires it produces.
__________________
Brian Finster shavin' and smokin' a cigar?!?! |
#22
|
|||
|
|||
Re: Cat 777D Mining Truck
won't the lugs be stickin out ????or is that used to make the mold and then the casted tire??
__________________
I built this thing and have it working now what do I do with it? |
#23
|
|||
|
|||
Re: Cat 777D Mining Truck
TD9-this part will be used to make a two-piece flexible mold. Then the liquid rubber for the tire will be poured into the mold. Let it cure then hopefully I will have a tire.
|
#24
|
||||
|
||||
Re: Cat 777D Mining Truck
Do you have to coat the master with varnish like they do with sand casting? That would aid in releasing it from the rubber.
|
#25
|
|||
|
|||
Re: Cat 777D Mining Truck
ahhhhh now i get it lol sorry i just didn't grasp the whole concept but now i do i wish i could make a solid mold so i can use it quite a few times like at a tire plant or something there is too much of a process for me to make tires i think unless i can buy solid rubber lol
__________________
I built this thing and have it working now what do I do with it? |
#26
|
|||
|
|||
Re: Cat 777D Mining Truck
Yes steve, This is the hard part. Varnish will not work but I have to finish it really smooth so it will release. I wanted to use glass filled delrin for the plug because it machines easy and you can mold directly from it but a 3-1/2" pc. cost over $200 with shipping and I only need a 1-1/4" slice and I probably would never use the rest of it so I went with the mdf but finishing it will take a while.
|
#27
|
|||
|
|||
Re: Cat 777D Mining Truck
TD9-it is a long and time consuming process but I didn't think I had any other options. I e-mailed a couple of the foreign sites and although they did not have exactly what I needed I was going to buy their tires anyway but I never even got a response from them. Not sure how to deal with them maybe it has to be in their language, not sure?
|
#28
|
|||
|
|||
Re: Cat 777D Mining Truck
do you need some delrin i shere i got some liking around at the shop for you if all you need is a 1 1/2 pice think it 4" but that onlu take seconds to make it 3 1/2 lol let me know we got some scrap think there is some 6" around too
__________________
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts. |
#29
|
|||
|
|||
Re: Cat 777D Mining Truck
Mog-thanks-maybe I should have ask around before I started. I am too far along now to start over but if this doesn't work I may get back to you. I am waiting for the silicone & rubber to make the molds and tires so I should know something in a couple of weeks.
|
#30
|
|||
|
|||
Re: Cat 777D Mining Truck
Great looking tyres, will follow progress closely. To find tyres that matches are a very hard part, Have had som thoughts of building a Pete with lowboy to transport my D8, but then it is the tyre problem again.
I you find a easy way of making those you will solve a lot of problems for us others. Dan |
#31
|
|||
|
|||
Re: Cat 777D Mining Truck
D8R-thanks a lot-I agree tires can be a huge problem especially when you are not building by the common scales. I did not want to make my own tires but I felt like I had no other options. This is not an easy solution but there is not a lot of work involved just a lot of time. For me making the master part was the hardest job. The mold and tires just require some time & patience. A machinist would probably make the master part from aluminum and you could spray the release directly on that and make the molds. I spent several hours with the finish on the wood part I made so the silicone will release from it. Hopefully in a few days I can see the results of my work.
|
#32
|
||||
|
||||
Re: Cat 777D Mining Truck
Hi tom ..Not sure how far along you are with your tires but i did find this site with supplies and alot of free intresting how -to vids ..Any chance you could give us a bit of a tututial on how you are going about it...Cheers Lou
http://www.freemansupply.com/video.htm |
#33
|
|||
|
|||
Re: Cat 777D Mining Truck
T-n-T Lou-thanks for the link but I already have my supplies. I have the molds started and I am taking pictures as I go along so maybe I can do a how-to if everything works out okay.
|
#34
|
|||
|
|||
Re: Cat 777D Mining Truck
Okay fellas, I have a tire! I will try to show how I did this. First step-I bedded the master part 1/2" deep in modeling clay. I put 4-3/8" steel balls in the corners and sprayed in the release wax.
Then I poured the top half of the mold- After this cured for 16 hrs. I turned it over and removed the modeling clay and the steel balls and put the stems on for fill holes and air vents and sprayed the release wax on this surface. I then poured the other half of the mold. |
#35
|
|||
|
|||
Re: Cat 777D Mining Truck
Aftter 16 more hrs. of cure time I separated the mold halves and this is how it looked-
This is the molds ready for pouring the tires- I sprayed release wax on the molds and poured the black rubber mixture in the molds. To speed up this process I filled the bottom half about 2/3 full before closing the molds- I had the molds on a perfectly level table to pour in the remaining rubber. I feel this is an important step to be sure the mold is full and to release all air. If air gets trapped in the mold the tire will be flawed. |
#36
|
|||
|
|||
Re: Cat 777D Mining Truck
After an overnight cure I separated the molds and this is the first tire right out of the mold-
Another- I have these stems on the side of the tire from the pour holes and air vents but I can grind these off and turn this to the inside and I don't think it will be a problem. Using this process I don't see any way to avoid this and I have a few tiny air bubbles on the fill side but I believe I can rig a shaker on the table and possibly solve this. I am happy with the results but will try to improve on the remaining tires. If anyone has any questions I will be glad to answer them. |
#37
|
||||
|
||||
Re: Cat 777D Mining Truck
Interesting! Thanks for sharing!
kerst |
#38
|
||||
|
||||
Re: Cat 777D Mining Truck
WOW that is really nice. I think if you had a small autoclave that remedy the air bubbles. Can you put a ruler next to it for size?
|
#39
|
||||
|
||||
Re: Cat 777D Mining Truck
Modelman, Those tires are looking good, I use a vacuum pump from Harbor Frieght and a garage sale pressure cooker as a vacuum chamber for moisture removal from Powder Coating powder, my thought is that would remove the air bubbles from the rubber. So far I haven't seen any problem with this lash-up. Fred
|
#40
|
|||
|
|||
Re: Cat 777D Mining Truck
The urethane stuff I mold in my shop has do be "degassed", once mixed I place it in a vaccum chamber (with clear top) and pull a vac with a AC vac pump until it boils out. Then when molded you minimize the air bubbles such as you have in a simple hand poured mold.
The vac chamber I have is just a piece of 8 or 10" pipe with a bottom welded on, top machined flat and a piece of 1/2" lexan for a top sheet. Port in side for vac line from pump. The tires came out very nice.
__________________
Jeff |
Currently Active Users Viewing This Thread: 1 (0 members and 1 guests) | |
|
|