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dangermouse

Making Your Own Tyres

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Hello all

I have been reading discussions about some brands of tyres being better, silicone is great or banned and how people put after market tyres on to improve performance. Looking online and at the shops it seems that one is up for $8-15 for a set of tyres - which gives me 2 choices pick 1 or 2 cars for silicones or find a better option. I have searched the threads and found longbeach's article on making your own so was thinking I can do that - I will make tyres for all my cars I also thought might be handy to learn mold making for making details for my model trains as well -

 

Any of the discussions appear to be in older threads are people still making their own tyres?

Is there something I need to know that makes it not a good idea?..

Any one in sunny Brisbane doing/done this lately?

Any tips on where to buy the stuff and the approx. cost? I found the website from longbeach's tip but they are in Adelaide.

 

thanks

DM

Edited by penfold

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Hi DM,

 

Making your own tyres is quite easy, as they are the easiest object to mould. The upfront cost will be about $40 or $50 through. The smallest packet (500ml) of silicone moulding material is around $25, and a 200ml packet of polyurethane casting liquid for the tyres is about $14 ($26 for 400ml). That will make up at least 60 or 70 tyres. You will also need a black polyurethane tint which is another $10 for a 15ml bottle (goes a long way) and maybe another $5 or $10 for incidentals. I use a SHORE 40 compound for my scalextric cars. The 50 will last longer but the grip is not quite as good. I haven't tried 30, but I'd be worried about it holding its shape and/or coming off the rim at speed, unless you glued them.

 

Personally, I use Barnes Pinkysil for moulding. Its dearer than most, but its very runny, so is good for moulding up very small and intricate car parts. I use DalChem's Easyflex for the tyres, as its the only brand where you can buy smaller quantities than 1 litre. The only problem is that they are in different suburbs, and the DalChem one is very difficult for me to get to, so its a real paint to get new supplies. I could purchase online, but then you are up for another $15 in postage costs.

 

To make the moulds, I just pick out 1 or 2 really good clean, round and smooth tyres. Because your casts will come out identical, you need to choose tyres that look good, as well as are good. They should also fit tightly on the rim, or all the ones you cast will be loose as well. I then find a container just big enoiugh to hold the number of tyres I am wanting to cast, with a good 1cm gap around the outside and a similar gap between tyres. Glue the tyres to the bottom of the container, with the face that you want facing to the outside of the car facing up. (ie bad side down, good side up). Just use a light easy to unstick glue like a UHU glue stick. It just needs to hold the tyres lightly to bottom of the container so they don't float up into the silicon. Use the same or a similar container to work out how much silicone you need to make up (don't waste it, its expensive). You only need to cover the tyres by 8 to 10 mm at the most.

 

Once it has set, pulls the mould out of the container, turn it upside down, and pop each tyre out. You may need a very sharp stanley knife to score the very thin layer of mould over the bottom part of the tyre if you are using PinkSil, as its very runny, and actually gets under the tyres even with the glue. That give you your tyres moulds, Now, at this stage I use a very sharp pointy and small pair of scissors to cut open a couple of sections of the thin membrane on the top of each tyre mould (may not be necessary with other thicker silicones), just so I have a 2 mm wide hole or gap to pour the tyre compund into.

 

Then, start with very small amounts (20mm of compound will do 7 or 8 tyres, depending on the size), and mix together the polyurethane compounds, add a little dap of colouring, mix and then pour into each mould. I use little medicine bottles for this, as they are graduated, and come as small as 50mm in size, for about 10c each from the moudling suppliers. Just clean them up afterwards and reuse them. You can speed up the job, particularly if you are making very small tyres, by using small syringes to inject the mixture into each tyre mould. Again, they are pretty cheap at about 50c each and can be re-used 10 or 20 times before becoming difficult, as long as you clean them up. You can clean up the silicone and polyurethane using either Mineral Turps or Acetone, but I find Acetone more effective. Again, it can be re-used, as it is very expensive compared to turps.

 

This mehtod, I should point is, is a very quick and easy method for casting tyres, but it gives you tyres with only one good face. The face at the top of the mould that you use to pour the compound into will be rough, particularl if the mould overfills, and you will have to cut off the excess to fit on the rim. So you always have the good face facing outwards on the tyres. As very few people rotate the tyres on their slot cars nayway, this is not a real issue. If you wnated more perfect moulds, you would need to make up 2 part moulds. This takes a little longer, and is a bit more fiddly when pouring, but will give amore perfect reults. Mind you though, there is always a little leakage in any mould that is not machined, so you will still have to cut off thin dags of excess casting material anyway, it just won;t be as noticeable.

 

Hope this helps.

 

PS. If you don't want to go to the trouble of making your own, I make more than I need and sell them, to cover the cost of the tyres for my own cars. So if you only want 20 or 30 tyres, I can do them for you at a good price. I do quite a fair range of the older scalex tyres, for F1, sedans, le mans and rally cars.


Graeme

~~~~~~

 

(Life is like a sewer....................What you get out of it depends on what you put into it!)

 

My Website

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Just one question; tyres generally have a lip on both the inside and outside. How do you get the tyre out of the mould, or is the mould malleable enough that it can be popped out?


Beauty.

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Just one question; tyres generally have a lip on both the inside and outside. How do you get the tyre out of the mould, or is the mould malleable enough that it can be popped out?

good question just looked at a tyre now and yes I guess the silicone fills the lip and forms a plug in the middle when you make the mold. I have some rock casting moulds and the are fairly flexible.

Longbeach's website was very good - I also found another website where the guy actually made a mold with the tyre on a wheel he then removed the master tyre and with the wheel attached to the mold he poured the silicone around the wheel - one way to guarantee a good fit.

http://www.oldweirdherald.com/scalestuff/o.../silicones.html

Edited by penfold

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Just one question; tyres generally have a lip on both the inside and outside. How do you get the tyre out of the mould, or is the mould malleable enough that it can be popped out?

 

Matticus,

 

Yes, the mould is very flexible, and the tyres are just carefully popped out.


Graeme

~~~~~~

 

(Life is like a sewer....................What you get out of it depends on what you put into it!)

 

My Website

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using longbeach's technique you'll end up with a tire very close to a MJK, i've got some samples of longbeach's tire in 1/24, not bad for a home made tire...

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I followed GRT's instructions and made a batch of tyres.

 

Being my 1st attempt at moulding a cpl didnt turn out as I hoped but I had good results with others.

 

I dont know if the SCX tyres are made of something different but after making the moulds the original tyres came out abit slimey and the home made tyres seemed to be a bit big.

 

Ive only worked on the one car so far being my SCX aston martin. I sanded the tyres down a bit to get them running smooth and after a few laps they were gripping fantastic and I managed to set new lap records on both lanes in both directions. Down from 3.8 to 3.7 seconds.

 

I've since re-created a cpl of the moulds and have new tyres in the moulds setting overnight. Hopefully they will come out a tighter fit than my first attempt.

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BRRRRRR! That's Winnipeger for I wish I was down under right now. Hi guys, I'm new to the forum, but not slot car racing.

 

We use urethane to make our tires here. We have wood and plastic tracks in our club and most have found the urethane crosses over better. I can bring one car with me (like that ever happens) for the day and race both kinds of track. Especially now that I have my new SCP1's. I use Reoflex 40, which is made in the States by Smooth-On. Urethane stretches so much better than silicone. We have found that a copy of the slot.it sipt02 P2 will fit just about any modern hub and seat itself tight without glue. They can be sanded true in about 30 seconds, yet are much longer lasting than natural rubber. They stick!

 

I have started making individual molds because the tire comes out easier, and the molds are so good only 1 of 10 tires needs truing, unless the problem is with the hub. I also found a nice little mold frame that leaves a little rim around the top and allows the mix to form a pool. The pool helps release any bubbles better. The other plus is that after trimming off the membrane from the top, the side wall profile is almost perfect. I have seen many home made tires with a bit of a hollow on the inside from the formation of a concave meniscus. With an individual mold I can pour as few as 4 tires Fri evening and they are on the track Saturday.

 

I have a little less than a hundred cars and putting slot.it tires on them all would be too much money. and they stick! I was hesitant to try it at first, if only I'd known how easy it is.

 

In case of interest it is sold by;

Rowe Trading

4 Holder Ave.

Richmond

South Australia 5033

Tel: 61-8-8234-0000

Fax: 61-8-8234-2092

Ask for Mr. Chris Rowe

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BRRRRRR! That's Winnipeger for I wish I was down under right now. Hi guys, I'm new to the forum, but not slot car racing.

 

I have started making individual molds because the tire comes out easier, and the molds are so good only 1 of 10 tires needs truing, unless the problem is with the hub. I also found a nice little mold frame that leaves a little rim around the top and allows the mix to form a pool. The pool helps release any bubbles better. The other plus is that after trimming off the membrane from the top, the side wall profile is almost perfect. I have seen many home made tires with a bit of a hollow on the inside from the formation of a concave meniscus. With an individual mold I can pour as few as 4 tires Fri evening and they are on the track Saturday.

 

I have a little less than a hundred cars and putting slot.it tires on them all would be too much money. and they stick! I was hesitant to try it at first, if only I'd known how easy it is.

 

Hi Paul - thanks for the tips do you have in photos of the mold frame and the tyres -

A question for all who have responded to this thread - why do you need 1 type of silicone for the mold and a different type for the tyres? Reading the website about all the products people have mention they are all described as molding compounds... is it to do with the Shore strength? Is there any reason why I can't make the mold out of Reoflex 40 as well as the tyres?

 

thanks

David

Edited by penfold

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BRRRRRR! That's Winnipeger for I wish I was down under right now. Hi guys, I'm new to the forum, but not slot car racing.

 

I have started making individual molds because the tire comes out easier, and the molds are so good only 1 of 10 tires needs truing, unless the problem is with the hub. I also found a nice little mold frame that leaves a little rim around the top and allows the mix to form a pool. The pool helps release any bubbles better. The other plus is that after trimming off the membrane from the top, the side wall profile is almost perfect. I have seen many home made tires with a bit of a hollow on the inside from the formation of a concave meniscus. With an individual mold I can pour as few as 4 tires Fri evening and they are on the track Saturday.

 

I have a little less than a hundred cars and putting slot.it tires on them all would be too much money. and they stick! I was hesitant to try it at first, if only I'd known how easy it is.

 

Hi Paul - thanks for the tips do you have in photos of the mold frame and the tyres -

A question for all who have responded to this thread - why do you need 1 type of silicone for the mold and a different type for the tyres? Reading the website about all the products people have mention they are all described as molding compounds... is it to do with the Shore strength? Is there any reason why I can't make the mold out of Reoflex 40 as well as the tyres?

 

thanks

David

 

You make the mould from silicone because it doesnt stick to anything. You can pour it over your original tyres and then pull the tyres out.

 

And then you use the flex 40 to make the tyres.

 

I took some photos of the process

 

DSCF3173.jpg

Heres the toilet rolls ready to go for the moulds

 

DSCF3174.jpg

Tyres are inside and silicon has been poured over to make the moulds

 

DSCF3180.jpg

Heres the completed mould with the original tyre removed

 

DSCF3181.jpg

Two of the moulds with the new rubber tyre poured in

 

DSCF3182.jpg

OOO look at the pretty tyres. trimmed and ready to go

Edited by Johno

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OOO look at the pretty tyres. trimmed and ready to go

 

I'm interested to see how they they perform on a routed track.


* Avatar used with permission

 

Normal people worry me

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OOO look at the pretty tyres. trimmed and ready to go

I'm interested to see how they they perform on a routed track.

hopefully as good as the ones you buy from the shop..

I just put the silicone tyres of my slot.it 962 onto my 917k and whether I decide to make my own tyres (and I think I will) or not I need a pair of silicones for the 917k. It went from sliding, hopping and hard to control to just 'Beautiful' so much fun to drive on both my routed track and on carrera track.....so if they hold up as good as the 'commercial' ones and I think they would I'm sold will source some silicone and start making- first I think I will make a small video showing the difference between the 917k with and with out silicones on.

cheers

DM

 

ps Johno I assume they need a light sanding once you put them on the cars?

Edited by penfold

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OOO look at the pretty tyres. trimmed and ready to go

I'm interested to see how they they perform on a routed track.

hopefully as good as the ones you buy from the shop..

I just put the silicone tyres of my slot.it 962 onto my 917k and whether I decide to make my own tyres (and I think I will) or not I need a pair of silicones for the 917k. It went from sliding, hopping and hard to control to just 'Beautiful' so much fun to drive on both my routed track and on carrera track.....so if they hold up as good as the 'commercial' ones and I think they would I'm sold will source some silicone and start making- first I think I will make a small video showing the difference between the 917k with and with out silicones on.

cheers

DM

 

ps Johno I assume they need a light sanding once you put them on the cars?

 

 

Im unable to play cars atm due to rolling my ankle yesterday but I have got my SCX Aston Martin running great on the home made tyres. I had to sand them a bit as they rubbed on the body. (for some reason they were thicker than the originals). But after a bit of sanding the car ran great compared to when I was using the original SCX tyres. This was on my small routed track with sharp corners and it was able to handle the corners with very little if any sliding

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I have settled on urethane for the molds. I have found it more durable, stretches easier, and resumes it's shape after release almost instantly. The silicone molds worked fine, but developed an oval shape after a few pours. I pour either silicone or urethane into urethane molds. I use release agents all the time. I forgot a few times and the tires coming out of the mold either didn't come out or they had little clefts in the side, and/or sometimes what looked like they were laminated. I also found that the mix flows into the mold better when the release agent is used. As well, urethane is thinner when in the mixing pot and pours a little quicker before starting to thicken. I also tried blending the silicone with urethane to cast tires, but it would split in half when it stretched. I have read of some success with this, not for me though.

 

I am in the middle of a crash course on internet use, website publishing, html, url, and I will add posting pics to the list of things to learn. I'm told to go to Myspace and blah blah blah, I need to listen to the kids more often! I can email the pics to some one to post them. Ignore this I think I figured it out....

 

m_5e7d285dd1e9f593d1691aaecf1bd017.jpgm_eb487075c3ea680dce1d04896c3bdbf7.jpg

 

m_bf634ebeaa5c7dc50d50d9cce914f466.jpg

 

Well that's easier than I thought... thanks kids.

 

I'm using a small 1/2 ounce condiment cup. They molds are very flexible and release the tire easily, especially with the membrane that forms on top. They also make great mix cups. I pour as few as 4 tires at a time without wasting urethane.

Edited by paul gage

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Im a bit more mobile today so I hit the shed this morning and I must say Im a little disappointed with the tyres today. With the extra time to fully cure they are now alot harder to sand down than when I did the SCX pair straight out of the mould. The sandpaper I was using wasnt even scratching the surface. So I may have to make sure that I get the right straight out of the moulds.

 

Also my Aston Martin that was setting lap records the other day wasnt performing the same this morning so Im not sure what is going on there.

 

Im going to do another batch today and let them set overnight and then tomorrow when I have a full day off work I will get to work on putting them on my different makes of car and seeing how they go.

 

But overall a frustrating morning.

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I dont know if the SCX tyres are made of something different but after making the moulds the original tyres came out abit slimey and the home made tyres seemed to be a bit big.

 

Hi Johno,

 

I had the same problem when I tried to mould up some SCX tyres. They must contain some silicone or other compound that reacts with the silicone moulding compound. You could try making the mould from the urethane instead, but I got around it by sealing the SCX tyre with Johnson pledge. You could use anything like that, as long as it coats and seals the tyre, let it dry, then try moulding. It worked for me.


Graeme

~~~~~~

 

(Life is like a sewer....................What you get out of it depends on what you put into it!)

 

My Website

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I pour either silicone or urethane into urethane molds. I use release agents all the time.

 

i'm a novice here - is the urethane you use for the moulds the same as that you are making the tyres from?

 

is the release agent the same sort of product used for release agent for releasing plaster casts from urethane moulds (something like potassium soft soap)? or is it different for urethane-urethane moulding?

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I pour either silicone or urethane into urethane molds. I use release agents all the time.

 

i'm a novice here - is the urethane you use for the moulds the same as that you are making the tyres from?

 

is the release agent the same sort of product used for release agent for releasing plaster casts from urethane moulds (something like potassium soft soap)? or is it different for urethane-urethane moulding?

 

 

I have tried 2 brands, Smooth-On Universal Mold Release aerosol and Mann Ease Release 205 spritzer. Both have web sites if you want the ingreds. I use it to make the mold and to cast the tires. Not every time I pour though. I am getting 4 to 6 pours between applications. Clean them with isopropanol alcohol and reapply release agent. Too much and it can blur some finer details in the mold. I spray it on and then brush off as much as possible. Sidewall detail improves. Temperature and humidity play a small part in the quality of the mold. Too much humidity and more bubbles will form in the urethane, creating small bubble blobs on the inside of the tire that will need trimming after casting the tire. Dry environment, 72 deg. F is the manufacturers recommendation. I have not had to pre-treat the tire originals with any sealants. I just pay close attention when brushing off the excess release agent.

m_803445db0f10c3859d47b44e1db5dd5b.jpgm_b717f1684836678f36a176e9086dcb21.jpg

Edited by paul gage

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Too much humidity and more bubbles will form in the urethane, creating small bubble blobs on the inside of the tire that will need trimming after casting the tire. Dry environment, 72 deg. F is the manufacturers recommendation. I have not had to pre-treat the tire originals with any sealants. I just pay close attention when brushing off the excess release agent.

hi Paul the tyres look good - shame you are OS or I would just see if you could make me some :)

I may be confused - do you make the mold and the tyres from the same urethane material?

what does the tyre feel like compared to a standard rubber tyre? is it sticky or softer? I have a pair of slot.it silicones they definitely feel different to the other tyres I would say they feel smoother and softer and more flexible....

 

Any one in Brisbane making their own? give me a PM

cheers

DM

Edited by penfold

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Hi Guys,

The issue between the SCX tyres and the silicone is a condition called inhibition and GRT is spot on with creating a barrier between the master and the silicone mold. If your finding that the silicone isnt holding shape its most likely due to the fact your wall thickness on the outside of the tool is too small. Try increasing it, I generally aim for side walls on tools around 20mm + . I'm curious to see that your using urethane as a medium to make the mold from, I would of thought the tear strength wouldnt of been that wonderful when demoulding a part. What shore A hardnesses are you using?


Regards

Rob

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All my moulds even for bodies have a wall thickness of only about 10mm! But I place the mould back into its original moulding box when casting. The mould box is cheaper that all the extra silicone.

 

Phil

I agree with that Phil, most of the moulds we ran were for production qty's of prototypes cycling from 30-50 tool shots in a day the cost of the extra silicone was far out wieghed by the labour to process the moulds. Some of the other moulds mad a more or less glove moulds where we painted silicone on to a desired thickness and then layed a plaster shell over it to form the support.


Regards

Rob

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Paul who posted some pics and suggestions in this topic has a good system for making molds - he pours them in little plastic cups...

 

I have some of his tyres and they are really good - I put a set on a Scalextrix JGTC Supra and it drives really well - great grip (I have a small routed track painted with flat house paint) fast cornering and a lot of fun...

 

I am going invest some time now in making my own tyres now - I am really impressed with the performance difference

 

how are your tyres going Johno? Is your ankle better?

 

The urethane that Paul uses seems to do the job

 

cheers

DM

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How many of the tyres you guys are making fail? What's the cheapest possible 'tyre' you can make? I'm interested 'cause I figure tyres about the size of the Slot.it rears are perfect for making tyre walls. I want to make tyres cheaply to use as decoration / protection around the track (and yes I'm contemplating chaining bunches of them together with scale chain against walls as well as digging them into raised banks..


Captain's log: We are enroute to some planet whose name I cannot pronounce to do something really complicated that I don't understand.

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